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Appendix G• • APPENDIX G Problem Area Summary C • ANALYSIS OF DRAINAGE PROBLEM AREAS WITHIN THE CITY OF SHOREWOOD PREPARED FOR THE CITY OF SHOREWOOD, MINNESOTA • January 23, 2006 Prepared By: WSB & Associates, Inc. 701 Xenia Avenue South, Suite 300 Minneapolis, MN 55416 (763) 541 -4800 (763) 541 -1700 (Fax) • TABLE OF CONTENTS CERTIFICATION I . INTRODUCTION .................................................... ..............................1 II. DISCUSSION OF PROBLEM AREAS .......................... ..............................3 III. SUMMARY AND RECOMMENDATIONS ................... .............................59 LIST OF TABLES TABLE 1- Areas Categorized As "Public Safety and Health" Problem Areas TABLE 2 - Areas Categorized As "Substantial Financial Impact To The City" Problem Areas TABLE 3 - Areas Categorized As "Public Nuisance" Problem Areas TABLE 4 - Areas Categorized As "Private Nuisance with Limited City Responsibility" Problem Areas TABLE 5 - Areas Categorized As "Private Nuisance With No City Responsibility" • Problem Areas TABLE 6 - Areas Categorized As "No Further Action Required" Problem Areas LIST OF APPENDICIES APPENDIX A - Opinion Of Probable Cost For Selected Problem Areas (Category 1 -5) APPENDIX B - Recommended Maintenance Activities (On -going or One -time projects) Analysis of Drainage Problem Areas within the City of Shorewood Shorewood, Minnesota WSB Project No. 1459 -04 TOC • CERTIFICATION hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly licensed professional engineer under the laws of the State of Minnesota. Steven Gurney, P.E. is Date: January, 2006 Reg. No. 40497 is Analysis of Drainage Problem Areas within the City of Shorewood Shorewood, Minnesota N'SB Project No. 1459 -04 I. INTRODUCTION • On September 4` 2005 a strong thunderstorm developed over the City of Shorewood. In the course of approximately three hours, close to six inches of rain fell within the City. During this time, large hail also was observed, stripping leaves from trees and adding to the general debris that was present within the storm sewer system. The City experienced a second storm on October 4` 2005. This storm produced approximately 4.5 inches of rain within a four hour period. The City requested WSB & Associates, Inc. look at the various drainage problem areas. The preliminary findings of this investigation are outlined within this report. To aid the City in planning for projects that will reduce the number of flood problem areas, we have ranked the problem areas based on a modified classification system. In order to maintain some consistency with the City's system previously established, we used the same categories with limited modifications. The criteria outlined in the Capital Improvement Program (1997 — 2001) were modified as follows: • Split "Private Nuisance" areas into two categories, one in which the City may share in the responsibility for the project and one that is entirely the responsibility of the private property owner and / or their neighbors. • Added a new category consisting of areas where no additional work is recommended. i The various categories are outlined below: 1) PUBLIC SAFETY AND HEALTH Primary attention will be paid to those projects that impact the public health or safety. These projects would include ice problems on the road, erosion that is causing a hazardous structural problem (i.e. undermining a road), or storm water that is causing a significant health problem (such as flooding the sanitary system). 2) SUBSTANTIAL FINANCIAL IMPACT TO THE CITY This category will include those projects that, while not endangering the public health, will still have a negative impact on the residents as a whole. Projects in this category include minor infrastructure replacement that cannot be funded cost effectively by other means. Other potential projects include erosion causing property damage and minor structure replacement. 3) PUBLIC NUISANCE This category includes those projects that cannot be considered a substantial hazard, are not likely to cause a financial loss to the City, but are a public nuisance. These projects include standing water in the roadway, unwanted flooding in public parks, and minor is projects. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page I WSB Project No. 1459 -04 • 4) PRIVATE NUISANCE WITH LIMITED CITY RESPONSIBILITY This category includes projects that are a nuisance to a single residence or small group of residences that the City Council deems that the City has some responsibility to help correct. These projects include those instances where a large drainage area is causing a problem to a small area or where a substantial portion of the runoff is generated within the City's Right -of -Way. In order for the City to participate, the homeowner(s) must be willing to provide a right - of -entry to City crews and provide Drainage and Utility Easement over improvements without cost. 5) PRIVATE NUISANCE WITH NO CITY RESPONSIBILTY This category includes projects that are a nuisance to a single residence or small group of residences that the City Council deems that the City has no responsibility to help correct. These projects include those instances where a limited drainage area, consisting of private property, is causing a problem to a small area. The nuisance problem will involve little or no runoff that is generated from City Right -of -Way. 6) NO FURTHER ACTION REQUIRED This category includes projects that are under way, or have been addressed through • various means, such as individual homeowners correcting the problem himself or herself or City crews fixing the problem. The problem areas are all evaluated and a category assigned so that the City Council can begin to prioritize the problem areas. Tables 1 -6 contain a list of the problem areas for each category along with a preliminary ranking of the areas within in each category. This ranking, along with the preliminary cost estimates, can be used by the City Council to determine the priority for fixing the problem areas. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 2 WSB Project No. 1459 -04 II. DISCUSSION OF PROBLEM AREAS • Following the September 4 1 storm, the City received several drainage complaints. Since that time, we have investigated each of the various areas to visit with concerned residents, gather additional information, take pictures, and where possible, observe the problems. The results of this preliminary investigation are presented in the following pages. Each problem area has a brief description of the complaint expressed by the property owner followed by a summary of the hydrologic characteristics of the subwatershed tributary to the site. Next, possible alternatives that may be considered to address the problems at the subject site are outlined. A preliminary cost estimate for each alternative is also provided. Following that is a recommendation by WSB as to how the City should proceed. Several of the areas are within private property and do not necessarily much additional investigation by City Staff or their consultants. However, there are several areas that, because of their proximity to or the amount of public property involved in the tributary area, will require further review. Unless otherwise noted, the hydrologic information is based on a cursory review of the subwatershed tributary to the problem area. The Soil Conservation Service's TR -20 method was used to estimate flow rates from the subwatershed directly tributary to the problem area. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 3 WSB Project No. 1459 -04 • Problem Area Number I — 6180 Murray Hill Road Description of Problem: The owner of 6180 Murray Hill Road has experienced flooding as a result of the September 4 th storm. The house is located at the base of a steep hill. At the top of the hill, two city streets, Murray Hill Road and Summit Drive, intersect at a "T" intersection. Runoff from Summit Drive is conveyed down the surface of the road, which is at an approximate 12.5% slope. It has been observed by City crews that the runoff from this road is flowing with such velocity that it does not stay on the road surface. Rather, it drops down the steep slope and flows towards the residence at 6180 Murray Hill Road. This is evident by the accumulation of sediment at the base of the hill. The resident has stated that they had flooding of their basement during the storm event. Hydrologic Information: • Tributary Area: 2.3 ac • Impervious Surface: 20% • Peak 10 -year Flow Rate: 5.8 cfs • Peak 100 -year Flow Rate: 10.2 cfs Possible Alternatives: • The following alternatives are available to correct the drainage problem at this site: 1. Installation of storm sewer and catch basins on Summit Drive. It is anticipated that the construction costs associated with this work will be approximately $31,000. 2. Regrading of Murray Hill Road and / or areas behind the west curb to provide conveyance for on the street surface, rather than down the steep bank. It is anticipated that the construction costs associated with this work will be approximately $2,300. 3. Grading of the yard to provide a swale that will intercept runoff coming down the steep slope and convey it to the wetland behind the residence. It is anticipated that the construction costs associated with this work will be approximately $2,900. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that additional analysis be undertaken to determine the depth of flow at this intersection so that the height of the constructed berm can be verified. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 4 WSB Project No. 1459 -04 Problem Area Number 2 — 6100 Apple Road Description of Problem: This residence is located at the bottom of a ravine, with the house cut back into the hill. The homeowner has attempted to redirect runoff around his house by constructing a drain tile system comprised of six inch HDPE and pea rock french drain system. During the heavy rains of September, the system was overwhelmed and several areas were eroded, depositing the pea rock on the downstream lawn. Hydrologic Information: • Tributary Area: 5.1 ac • Impervious Surface: 5% • Peak 10 -year Flow Rate: 7.7 cfs • Peak 100 -year Flow Rate: 15 cfs Possible Alternatives: .7 The homeowner could construct a new pipe with more capacity. Due to the proximity of the house, it is not recommended that additional ponding be provided uphill unless an emergency overflow route can be established. In order to accomplish this, the homeowner may have to coordinate the work with his neighbors. It is anticipated that the construction costs associated with this work will be approximately $16,000. • Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5). A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 5 WSB Project No. 1459 -04 • Problem Area Number 3 — Minnetonka Country Club Description of Problem: Discussion during the heavy storm events of September, the Country Club experienced flooding that resulted in the course being shut down for a few days. While much of the course was flooded initially, the extended duration of the flooding in the southeast corner of the course has the groundskeeper concerned. A field review of the area shows that the outlet pipe that conveys runoff from this area is an 8 -inch PVC line. Hydrologic Information: • Tributary Area: 147.2 ac* • Impervious Surface: 12 %* • Peak 10 -year Flow Rate: 141cfs ** • Peak 100 -year Flow Rate: 267 cfs ** *Based on a model developed as part of CSMP * *Considerable storage volume available on golf course. Peak rates represent runoff to golf course. Possible Alternatives: is The following alternatives are available to correct the drainage problem at this site: 1. Provide a larger pipe with more capacity to convey runoff from the southeast corner of the golf course. 2. Provide additional ponding within golf course, within areas that will not impact play. 3. Raise impacted greens above high -water level. 4. Combination of the above. The above alternatives could be constructed in phases or as one large project. Since the scope of this project could vary significantly, separate cost opinions have not been developed for the individual alternatives. Rather, a cost range has been provided to aid in planning and budgeting purposes. It is anticipated that the construction costs associated with this work will be approximately $120,000 to $533,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since there are areas off -site including City Right -of- Way that contributes runoff to the golf course. Since this is a large area containing lots of open space, and there is potential for a comprehensive storm water management plan for this area, it is recommended that further analysis be • undertaken to develop a comprehensive system that will provide treatment and rate control for the watershed as a whole. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 6 WSB Project No. 1459 -04 Problem Area Number 4 — 5925 Galpin Lake Road Description of Problem: This residence is a new home constructed on a previously vacant lot. The homeowner is concerned with the amount of runoff that is conveyed through his property from the road. Hydrologic Information: • No hydrologic analysis completed since this problem has already been addressed. Possible Alternatives: The homeowner has redirected the runoff conveyed through his property by constructing a berm adjacent to the road surface. The berm will contain runoff within the road surface. It is then conveyed downstream to a low point, where it will discharge to Galpin Lake. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the problem has been addressed through the building permitting process. A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. 0 is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 7 WSB Project No. 1459 -04 • Problem Area Number 5 — 25360 Birch Bluff Road Description of Problem: The culvert at the driveway entrance to this property is damaged and in need of replacement. The CMP is deteriorated along the bottom of the culvert and both ends of the culvert are partially collapsed. This has resulted in greater flow velocities and erosion at both ends of the culvert. The culvert is located on the drainage ditch that conveys runoff from a large portion of the City directly to Lake Minnetonka at Crescent Beach. Hydrologic Information: • Tributary Area: 86.1 ac (direct), 306.4 ac (total tributary area)* • Impervious Surface: 30 % ** • Peak 10 -year Flow Rate: 8 cfs * ** • Peak 100 -year Flow Rate: 14 cfs * ** * Based on subwatershed delineated in CSMP. ** The amount of impervious surface is estimated from the Curve Numbers previously established during preparation of the City's CSMP. • * ** Flow rates based on full flow capacity of existing culvert (10 -year) and peak flow rate without overtopping of driveway (100- year). Additional rate control is provided by upstream culvert at Pleasant Place. Possible Alternatives: The following alternatives are available to correct the drainage problem at this site: 1. Do nothing. 2. Replace culvert. It is anticipated that the construction costs associated with this work will be approximately $15,000. Recommendation: It is recommended that this problem area be categorized as a "Public Safety and Health" area (Category 1) since the drainage ditch is an integral part of the City's storm water conveyance system. The City will replace this culvert in the spring. is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 8 WSB Project No. 1459-04 Problem Area Number 6 — 26220 Wild Rose Lane Description of Problem: During the heavy rainfalls of September, the resident experienced basement flooding. The water in the basement was approximately 2 — 2 %2 feet deep. The backyard of the residence contains an in- ground swimming pool that is located at the base of a steep hill. To gain access to the pool from the house, there is an egress door located below ground, as well as a lookout window. The runoff seems to have entered through these openings as evident by the debris line on the lookout window. Hydrologic Information: • Tributary Area: 1.5 ac • Impervious Surface: 15% • Peak 10 -year Flow Rate: 3.9 cfs • Peak 100 -year Flow Rate: 6.9 cfs Possible Alternatives: The following alternatives are available to reduce the risk of flooding at the basement of this residence in the future: is 1. Seal the low - building openings. It is anticipated the construction costs associated with • this work will be approximately $12,500. 2. Provide a drainage swale around the back of the lot to convey runoff around the home. It is anticipated the construction costs associated with this work will be approximately $6,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5). A letter will be sent to the resident recommending that they contact their neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. Since this property has experienced flooding of the basement, it is further recommended that this be given a higher priority if the City does decide to get involved in private drainage problems. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 9 WSB Project No. 1459 -04 Problem Area Number 7 — 5925 Grant Street Description of Problem: This residence is located at the lowest point of a subwatershed that includes a portion of the City of Excelsior. A series of culverts are located in the roadway ditch in the front of the yard. To alleviate standing water in the low backyard area, a 4 -inch PVC drain tile was installed to convey runoff from this lowpoint to the storm sewer located in the street Right -of -Way. The inlet to this drain tile consists of a small hole dug into the yard supported by landscape bricks. A screened grate was placed over the bricks. During the September rainfall event, this area flooded resulting in water in the basement of the residence. It was observed that the landscape bricks that supported the grate had collapsed, partially blocking the drain tile line. The storm sewer system crosses below Park Street and discharges to a drainage ditch located within the City's Right -of -Way. At the end of the ditch, adjacent to the TH -7 Right -of -Way, a resident has constructed a horseshoe shaped berm in an attempt to block runoff from flowing across his property. The height of this berm is approximately 3-4 feet high. Based on review of the City's 1 -foot contour information, it appears that there is approximately 7 feet of fall from the outlet of the storm sewer system to the top of this berm. Therefore, it is unlikely that the berm is creating any tailwater impacts on the Grant Street storm sewer system. The City has an existing sewer easement across the property containing the berm. It is recommended that the City instruct the homeowner at 5965 Grant Street to remove the berm. • Hydrologic Information: • Tributary Area: 1.7 ac* (direct), 8.9 ac total (tributary to Park St. storm sewer) • Impervious Surface: 9% (direct), 25% (total area) • Peak 10 -year Flow Rate: 19.7 cfs • Peak 100 -year Flow Rate: 34.3 cfs *Area within City of Excelsior has been estimated based on field visit. Possible Alternatives: Constructing a larger storm sewer system with additional capacity would reduce the flooding potential in this area. It is anticipated the construction costs associated with this work will be approximately $42,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since the runoff involves City Right -of -Way and a portion of the storm sewer system is a City owned system. It is recommended that additional analysis be undertaken to design a comprehensive system in . this area. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 10 WSB Project No. 1459 -04 Problem Area Number 8 — 20955 Ivy Lane is Description of Problem: The resident is complaining of small "sink holes" in her yard. It appears that these eroded areas are a result of the gutter downspouts from the garage area, which are directed toward the areas that have eroded. The resident was requesting that fill be placed in these areas since it is adjacent to a City drainage ditch. Hydrologic Information: • No hydrologic analysis completed since the erosion is located on private property. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6). A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. • • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 11 WSB Project No. 1459 -04 • Problem Area Number 9 — 4980 Suburban Drive Description of Problem: The owner has experienced a wet basement. He believes this is due to the neighbor's gutter downspouts being directed toward his foundation. In addition, during the October rainfall event the homeowner observed that runoff from the neighbor's yards has conveyed down a small hill in his backyard and across his driveway, resulting in erosion to the gravel driveway. The eroded material is then deposited in a low area adjacent to this property. Hydrologic Information: • Tributary Area: 0.5 ac • Impervious Surface: 37% • Peak 10 -year Flow Rate: 1.6 cfs • Peak 100 -year Flow Rate: 2.6 cfs Possible Alternatives: The following alternatives are available to reduce the potential for further erosion in this area: 1. Installation of a small private drainage system to convey runoff under the driveway. It is anticipated that the construction costs associated with this work will be approximately $6,500. 2. Construction of a berm to contain runoff within the yard or spread it out so that localized erosion is not experienced. It is anticipated that the construction costs associated with this work will be approximately $4,300. 3. Paving driveway. It is anticipated that the construction costs associated with this work will be approximately $7,800. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5). A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Analysis of Drainage Problem Areas within the City of Shorewood January 23,1006 Shorewood, Minnesota Page 12 WSB Project No. 1459 -04 Problem Area Number 10 — 25720 / 25 722 Wild Rose Lane Description of Problem: The property owner has experienced erosion of his driveway. A review of the site showed that the driveway culvert at this location was almost completely plugged. Runoff from the roadway that would have been conveyed under the driveway by this culvert instead ran down the driveway thereby causing erosion. The property owner has since regraded the front yard and driveway to block street runoff from entering his property. In addition, the City has built up a small bituminous curb over the driveway that will convey runoff past the driveway and into a low area west of the property. Hydrologic Information: • No hydrologic analysis completed since the property owner was fixing this area. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the property owner has addressed the problem. A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. 0 • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 13 WSB Project No. 1459 -04 • Problem Area Number 11— 25575 Smithtown Road (Lake South Auto) Description of Problem: During the September rainfall event, the business owner reported flooding of his shop area. A catch basin is located in the Smithtown Road ditch, immediately east of the paved area in front of the shop. Runoff intercepted by this catch basin is conveyed under Smithtown Road by a storm sewer system that discharges to the Regional Trail ditch. The primary structure for this property has experienced flooding on several occasions. During the last events approximately 8 inches of water covered the finished floor of the building. In addition, runoff inundated the low point of Smithtown Way Roadway, located approximately 75 feet west of Smithtown Road, and the intersection of Smithtown Road and Smithtown Way. Further observations by the City during the October rainfall event indicated that runoff was being trapped by the curb that has been placed around the edge of the parking lot, by the owner, in front of the business. In addition, it has been observed that the capacity of the catch basin immediately east of the driveway is exceeded. Hydrologic Information: • Tributary Area: 7.4 ac • Impervious Surface: 19% • • Peak 10 -year Flow Rate: 14.9 cfs • Peak 100 -year Flow Rate: 26.7 cfs Possible Alternatives: 1. The Public Works Department has swapped out the inlet grate for the catch basin located immediately east of the subject driveway to increase the capacity of the drainage inlet. 2. If the increased capacity of the inlet grate remains inadequate, modifications to the driveway will be required to redirect runoff to the mainline structures. It is anticipated that the construction costs associated with this work will be approximately $19,000. Recommendation: It is recommended that this problem area be categorized as a "Public Nuisance" (Category 3.) • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 14 WSB Project No. 1459 -04 Problem Area Number 12 — 21165 Minnetonka Boulevard Description of Problem: This home was recently constructed on a subdivided lot. As a requirement of the construction, the homeowner constructed a private drainage system within the City Right -of -Way. Runoff from a small depression located on his lot is conveyed to the storm sewer system through a flared end section (FES) located on the property. The system discharges to the roadside ditch located downstream along Minnetonka Boulevard. The storm sewer system appears to have replaced a series of culverts in two downstream driveways. To replace these culverts, catch basins were added at the driveways that connect to the private drainage system. The homeowner originally contacted the City to express concern that the system was clogging with debris. He also expressed concern that an upstream culvert was clogged and redirecting runoff through his front yard rather than along the roadside ditch. He also expressed concern with the amount of standing water that was in the depression on his property. The homeowner indicated that he plans to place fill in the depression to eliminate standing water below the FES. Subsequent conversations with the property owner indicate that, at times, stormwater runoff was actually flowing into the depression through the FES. Based on this, it appears that the storm sewer system may have surcharged and back -flowed into the depression area. Once the peak subsided, the water did drain out of the depression to the elevation of the FES. Hydrologic Information: • Tributary Area: 6.0 ac • Impervious Surface: 25% • Peak 10 -year Flow Rate: 13.3 cfs • Peak 100 -year Flow Rate: 23.2 cfs Possible Alternatives: To reduce the risk of clogging, City crews have replaced the standard CB grates with beehive - type grates. In addition, the trash guard on the FES at the downstream discharge point to the Minnetonka Boulevard ditch was removed. This trash guard had trapped debris within the FES. City crews also removed a portion of the damaged culvert upstream of the property, which should reduce the potential for runoff being conveyed across the front yard of the 21165 Minnetonka Boulevard. In order to reduce the potential for runoff backflowing into the depression area located on the property, the homeowner may wish to consider the following options: 1. Installation of a flap gate within the storm sewer line between the FES and the catch basin. It is anticipated that the construction costs associated with this work will be approximately $4,000. U • 2. Construction of a parallel storm sewer system to convey runoff from Minnetonka • Boulevard. The system could be installed over the top of the previously installed system Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page is WSB Project No. 1459 -04 • to convey the runoff collected by the catch basins adjacent to Minnetonka Boulevard. It is anticipated that the construction costs associated with this work will be approximately $12,000. 3. Do nothing. The backflow is a temporary inconvenience that, with proper grading of the depression area, could be reduced to occurring only during large intensity storms. The emergency overflow elevation for this depression area is approximately two feet lower than the low building opening of the new home at 21165 Minnetonka Boulevard. Provided that overflow elevation is maintained, it is likely that adequate freeboard will be provided for this property. 4. Other, homeowner - initiated solution. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance With No City Responsibility" area (Category 5). This situation would normally be categorized as a "Private Nuisance With Limited City Responsibility" area (Category 4), but since this private storm sewer system was required to develop the lot, it should remain a private system. A letter will be sent to the residents recommending that they contact their engineer to discuss the operation of the storm sewer system and potential solutions to the back flow condition. • No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 16 WSB Project No. 1459-04 Problem Area Number 13 — 4770 Lakeway Terrace • Description of Problem: This property is located near the low point of the Lakeway Terrace cul -de -sac. The property owner is complaining that during the recent storms, runoff was conveyed over his landscaped berm and through his side yard to Lake William. There is a storm sewer system in the street that conveys runoff from a drainage ditch as well as runoff from the road surface. Catch basins are located at the street low point. The catch basin on the west side of Lakeway Terrace has a beehive casting that appears to be slightly silted in. During the September storm event, it is possible that this casting became plugged with debris, as there were a lot of leaves dropped from trees as a result of hail. A review of City records did not yield any specific information as to a drainage and utility easement, although, typically, there is a 10 -foot easement provided along each side of the common lot line. Hydrologic Information: • Tributary Area: 3.4 ac • Impervious Surface: 14% • Peak 10 -year Flow Rate: 7.8 cfs • Peak 100 -year Flow Rate: 14.0 cfs Possible Alternatives: is The following alternatives are available to reduce the potential for runoff being conveyed through this property: 1. Install a different casting that will allow debris to enter the CB. A stool grate such as the Neena HR- 4341 -A casting is recommended. It is anticipated that the construction costs associated with this work will be approximately $900. 2. The road grade could be lowered on the east edge of the roadway. This would convey runoff back to the drainage ditch. There are drawbacks to this proposed system, as it would impact an existing force main and lift station located in the Right -of -Way in this location. It is anticipated that the construction costs associated with this work will be approximately $12,000. 3. Construction of a higher berm along the property would allow additional runoff to pond on the road surface in this area before being conveyed across the property. This construction would result in the disturbance to front yards that are currently in good condition. It is anticipated that the construction costs associated with this work will be approximately $1,700. 4. Do nothing. The remainder of the overflow route does appear to be well graded away from structures; therefore, flooding potential is minimized. It does not appear that the Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 17 WSB Project No. 1459-04 • runoff conveyed along the lot line of this property would result in a flooding risk to the adjacent homes. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance With Limited City Responsibility" area (Category 4). It will be recommended that the City look at future improvements in this area that may reduce the potential for runoff being conveyed along the common lot line. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 18 WSB Project No. 1459 -04 Problem Area Number 14 — 28070 Woodside Road 0 Description of Problem: This property has experienced partial erosion of the timber retaining wall that has been constructed along the bluff overlooking Lake Minnetonka. In order to convey runoff from the backyard to the lake, a downspout consisting of two CMP flumes have been installed. The entrance to these flumes consists of grouted riprap to provide a smooth transition. Based on a field visit, it appears that runoff from the adjacent property to the north is conveyed to this downspout. During the site visit, it was observed that the grass surface had been bent over, indicating that runoff had come from that property and been conveyed to the downspout. Based on a review of the grading plan for the adjoining property, the construction of the new house does not appear to have significantly altered the drainage patterns that existed prior to the construction of the new house. Hydrologic Information: • Tributary Area: 1.1 ac • Impervious Surface: 16% • Peak 10 -year Flow Rate: • Peak 100 -year Flow Rate: Possible Alternatives: • The property owner has already fixed the eroded areas. The following alternatives are available to reduce the potential for future erosion in this area: 1. Reconstruct the entrance to the downspout by building up the grouted riprap area adjacent to the entrance to the culverts. This would reduce the chance of water flowing over the bluff and eroding the material supporting the downspouts. It is anticipated that the construction costs associated with this work will be approximately $1,700. 2. Constructing a new drain on the north property that would reduce the amount of runoff being conveyed to the downspout. In order to convey this runoff to the lake, a separate pipe would have to be constructed through the bluff, which would require a variance from the Bluff Preservation Ordinance. Alternatively, the drain system could connect into the existing downspout at a lower elevation. It is anticipated that the construction costs associated with this work will be approximately $5,000. 3. Do nothing. The storm events that caused the erosion were large storm events that exceeded the 10 -year storm event, which is the typical design storm event for this type of system. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance With No City Responsibility" area (Category 5.) - Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 19 WSB Project No. 1459 -04 • A letter will be sent to the resident recommending that she contact her neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 20 WSB Project No. 1459 -04 Problem Area Number 15 — 800 Water Street (Frontier Electric • Description of Problem: The Frontier Electric shop building was flooded during the September storm event. The property is actually located within the City of Excelsior. The property owner contends that increased runoff from the City of Shorewood has resulted in his shop being flooded. These improvements include the reconstruction of the parking lot at the Shorewood Mall, as well as the construction of the new townhomes located immediately east of the mall. Subsequent inspection of the catch basins within the mall parking lot indicates that the runoff from the parking lot is conveyed to the storm sewer system that was constructed as part of the TH -7/41 improvements. This was verified during a subsequent rainfall event where no runoff was observed being conveyed to the TH -7 ditch east of the mall. There is an emergency overflow pipe that would convey runoff to the east should that ditch in front of the mall fill up. However, the area tributary to this ditch is relatively small, and it is not likely that runoff would be conveyed to the east. Hydrologic Information: The hydrologic analysis completed in conjunction with the Mn/DOT project to reconstruct the TH -7/41 intersection indicated that the tributary area to the Frontier Electric building was actually reduced. Possible Alternatives: • In addition to the work that was previously done during the reconstruction of TH -7/41, work is has been completed by other government entities. Mn/DOT has regraded the TH -7 ditch and improved the entrance to the culvert adjacent to the shop building. In addition, it is our understanding that the City of Excelsior will be removing the pipe adjacent to the shop, providing an open channel conveyance system that will be less likely to cause flooding of the shop building. It is anticipated that this work will be completed in 2006. Recommendations: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since it is being addressed by other government entities. A letter informing the property owner of this will be mailed, but no further analysis of this site will be made without direction from the City. is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 21 WSB Project No. 1459 -04 • Problem Area Number 16 — 27780 Island View Road Description of Problem: The homeowner expressed concern about standing water in his yard adjacent to his neighbor's property. The problem has been noticed since the neighbor installed a new pool. The property owner believes that a drain tile may have been damaged as part of the construction of the pool. Hydrologic Information: • Tributary Area: 1.6 ac • Impervious Surface: 4% • Peak 10 -year Flow Rate: 3.0 cfs • Peak 100 -year Flow Rate: 5.7 cfs Possible Alternatives: The following alternatives are available to correct the standing water problem at this site: 1. Construct a small drain system to the lake. The effectiveness of this system may be limited because the system would have to operate under hydraulic head since there is limited fill between the yard and the lake. It is anticipated that the construction costs associated with this work will be approximately $7,800. • 2. Because the area of standing water is relatively small, a rain garden could be constructed at the site low point consisting of wet tolerant trees or shrubs. It is anticipated that the construction costs associated with this work will be approximately $4,500. 3. Do nothing. Since the problem does not pose an immediate potential for flooding, doing nothing would be an appropriate option at this site. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance With No City Responsibility" area (Category 5). A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. J Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota P age 22 WSB Project No. 1459 -04 Problem Area Number 17— 23350 AcademyAvenue Description of Problem: The elevation of this house and the garage are below the elevation of the street adjacent to the property. During the September storm event, runoff was observed flowing onto the property. The house was flooded. A catch basin is located on the south side of the road, but this catch basin appears to have been plugged. Runoff then overtopped the road. It appears that the majority of the ditch on the south side of the road has been silted in over time and is in need of maintenance. Hydrologic Information: • Tributary Area: 1.2 ac • Impervious Surface: 18% • Peak 10 -year Flow Rate: 2.9 cfs • Peak 100 -year Flow Rate: 5.1 cfs Possible Alternatives: The following alternatives are available to correct the flooding problem at this site: • 1. Installation of a beehive manhole will reduce potential for clogging. It is anticipated that the construction costs associated with this work will be approximately $900. • 2. Excavation of a new ditch along the south side of the street would reduce the potential for runoff overtopping the road. It is anticipated that the construction costs associated with this work will be approximately $1,400. 3. Regrading the road to provide positive drainage away from the house may not be possible due to the steep grades of driveways across the street. However, installation of curb and gutter along this stretch of road, combined with some lowering of the road, may reduce the potential for runoff being conveyed toward the house. It is anticipated that the construction costs associated with this work will be approximately $53,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that additional analysis be undertaken to determine the most cost effective alternative to reduce flooding potential. • Analysis of Drainage Problem Areas within the City of Shorewood January 13, 2006 Shorewood, Minnesota Page 23 WSB Project No. 1459-04 • Problem Area Number 18 — 6180 Chaska Road Description of Problem: Runoff from Chaska Road washed out a landscape berm on the west edge of this property. Runoff was conveyed through the side yard and into an egress window, flooding the basement. A small drain system with small catch basin inlets located in the side yard did not convey the runoff at the high rate generated by the September storm. Hydrologic Information: • Tributary Area: 1.3 ac* • Impervious Surface: 7% • Peak 10 -year Flow Rate: 2.5 cfs • Peak 100 -year Flow Rate: 4.8 cfs * Area is estimated from CSMP Subwatershed Boundaries since the City's 1 -foot contour information does not extend into Chanhassen. Possible Alternatives: The homeowner is considering the following alternatives to correct the drainage problem at this site: • 1. Construction of a more defined swale to provide an overflow route through the side yard of this residence. In addition, increase the height of the grading around the egress windows. It is anticipated that the construction costs associated with this work will be approximately $3,200. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance With Limited City Responsibility" area (Category 4.) It will be recommended that the City look at future improvements to reduce the potential for flooding at this property. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 24 WSB Project No. 1459-04 Problem Area Number 19 — 26025 Birch Bluff Road Description of Problem: Runoff from the road has eroded the area around the driveway. Hydrologic Information: • No hydrologic analysis was completed since the problem has been addressed. Possible Alternatives: City crews have already corrected this erosion problem by building up a bituminous curb along the edge of the road and backfilling the eroded area. It is anticipated that this work has addressed the erosion problem. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the City maintenance crews have fixed this area. A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. is • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 25 WSB Project No. 1459 -04 • Problem Area Number 20 — 22015 Stratford Place Description of Problem: During the large September rainfall event, runoff from the drainage channel adjacent to this property may have scoured away part of the bank on the north side of the channel. Continued high flows in this drainage channel may result in additional erosion of the channel, thereby threatening the foundation of the house. During the site visit, it was noted that the 36 -inch culvert under Stratford Place was almost completely clogged at the inlet. The City removed the debris at this site. Hydrologic Information: • Tributary Area: 45 ac* • Impervious Surface: 25 % ** • Peak 10 -year Flow Rate: 66.2 cfs • Peak 100 -year Flow Rate: 116.6 cfs * The majority of the subwatershed is in the City of Chanhassen. Tributary area outside the City limits is estimated from subwatershed boundaries established during development of the City's CSMP. ** The amount of impervious surface is estimated since the majority of • watershed is in the City of Chanhassen. Possible Alternatives: It is recommended that the City of Chanhassen be contacted to discuss repairs in this area since the majority of the area tributary to this problem is within their boundary. The following alternatives are available to correct the erosion problem at this site: 1. Extend the culvert under Stratford Place. A manhole could be added beyond the storm sewer extended up through the channel to collect runoff prior to the point where it begins to erode the bank of the existing home. The length of the storm sewer is approximately 100 feet. It is anticipated that the construction costs associated with this work will be approximately $27,000. 2. Armoring along the channel bank to protect the foundation of the house along with installation of riprap adjacent to Apple Road is recommended. It is possible that the riprap could be placed only in selected portions of the channel that are posing a threat to the stability of the roadbed. It is anticipated that the construction costs associated with this work will be approximately $18,000. Recommendation: It is recommended that this problem area be categorized as a "Public Safety and Health" area (Category 1) since further erosion may threaten both the City's roadway and the private • residence. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 26 WSB Project No. 1459 -04 Problem Area Number 21— 5915 Grant Street . Description of Problem: The property owner experienced flooding in her yard. This residence is adjacent to 5925 Grant Street. The description of the problem, hydrologic information, and possible alternatives are the same for this property as those outlined in Problem Area Number 7. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since the runoff involves City Right -of -Way and a portion of the storm sewer system is a City owned system. It is recommended that additional analysis be undertaken to design a comprehensive system in this area. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 27 WSB Project No. 1459 -04 • Problem Area Number 22 — 5635 Harding Lane Description of Problem: Runoff from adjacent homes is conveyed through the backyard of this property. The runoff is conveyed by overland flow on the property. The catch basin is located on the north property line of this property, but it does not appear that the catch basin fully intercepts all runoff conveyed through the backyards. There is a drainage and utility easement on the back 50 feet of the lot. This does not appear to coincide with the primary flow path. This problem area was previously studied in 2003 and a draft version of the report was presented to the City for review. The project was tabled since there was not a consensus with the impacted property owners at that time. Hydrologic Information: • Tributary Area: 2.8 ac* • Impervious Surface: 30 %* • Peak 10 -year Flow Rate: 6.0 cfs • Peak 100 -year Flow Rate: 12.2 cfs * Based on model previously developed as part of the 2003 Harding Lane Comprehensive Stormwater Management Plan. • Possible Alternatives: The following alternatives are available to correct the drainage problem at this site: 1. The backyard area could be regraded so that the drainage swale is moved further away from the walkout opening. It is anticipated that the construction costs associated with this work will be approximately $9,000. 2. Construction of a catch basin and storm sewer upstream of the project would intercept more water before it is conveyed onto this property. This system would be connected to the existing catch basin. It is anticipated that the construction costs associated with this work will be approximately $13,000. 3. The construction of the improvements suggested in the 2003 study could address problems within the whole Harding Lane area. Adjusted for inflation, these costs are anticipated to be approximately $87,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) A letter will be sent to the resident recommending that they contact their neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis • will be undertaken by WSB on this problem area unless directed by the City to do so. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 18 N'SB Project No. 1459 -04 Problem Area Number 23 — 5615 Harding Lane • Description of Problem: This is a property immediately north of 5635 Harding Lane. The runoff that is not intercepted by the catch basin located in the side yard of this property and 5635 Harding Lane is conveyed through this backyard. A retaining wall has been partially eroded and the runoff ponds in the homeowners garage. The hydrologic information and possible alternatives are the same for this area as those outlined for Problem Area Number 22. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) A letter will be sent to the resident recommending that they contact their neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. Since this property has experienced flooding of the garage, it is further recommended that this be given a higher priority if the City does decide to get involved in private drainage problems. • • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 29 WSB Project No. 1459-04 • Problem Area Number 24 — 23980 Yellowstone Trail Description of Problem: This property is concerned about the current high water level of Mary Lake. Trees are being flooded on this property. A review of the Minnesota Department of Natural Resources website indicates that no Ordinary High Water Level has been determined for this lake. Hydrologic Information: • Tributary Area: 61.8 ac • Impervious Surface: 43% • Peak 10 -year Flow Rate: 133 cfs* • Peak 100 -year Flow Rate: 231 cfs* *Basin is actually land- locked. Flow rates represent peak runoff rates to the basin. Possible Alternatives: The following alternatives are available to correct the nuisance flooding problem at this site: 1. Construction of an outlet for this basin. The proposed storm sewer improvements for • Minnetonka Drive could easily be modified to include an outlet for this basin. This outlet pipe would be relatively small and would function as an emergency overflow. It is anticipated that this pipe could be set at an elevation two feet lower than the existing overflow elevation. It is anticipated that the construction costs associated with this work will be approximately $207,000. 2. Pump down the basin. The City did this for a period of time this fall. The costs associated with this option would vary depending on the amount of time the pump would run, and the number of occasions that the pump would have to be brought to this location. 3. Do nothing. The emergency overflow elevation of Mary Lake is approximately 957.1 and the lowest floor elevation of the adjacent elevations is 957.5. This provides 0.4 inches of freeboard, which is less than ideal, but would provide some buffer so that if the City were not able to pump, the water would overflow from the lake before flooding the residence at 23955 Clover Lane. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that an outlet from Mary Lake be constructed as part of the Minnetonka Drive storm sewer improvement project. is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 30 WSB Project No. 1459 -04 Problem Area Number 25 — 23955 Clover Lane • Description of Problem: This property is also located on Mary Lake. The description of the problem, hydrologic information and possible alternatives are the same as those outlined for Problem Area Number 24. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that an outlet from Mary Lake be constructed as part of the Minnetonka Drive storm sewer improvement project. Since this residence has the lowest low floor elevation, the property owner should consider obtaining sand bags to protect his building in the event that the water level rises and the City is not able to pump. • • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 31 WSB Project No. 1459-04 • Problem Area Number 26 — 5815 Eureka Road Description of Problem: A new house was constructed south of this property and it has blocked the drainage from the subject property. An old drain tile existed prior to construction of the new house, but it was damaged during construction of the new house. The drain tile conveyed runoff to an existing drainage ditch located south of the new house construction. New drain tile was installed, but this does not appear to be functioning properly. During the heavy rainfall events, water has ponded in the low area in the southwest corner of this property. During the October storm event, it was observed that runoff overtopped to Eureka Road and was conveyed to the west through the backyards. (See Problem Area Number 35 and Problem Area Number 48.) Hydrologic Information: • Tributary Area: 2.9 ac • Impervious Surface: 5% • Peak 10 -year Flow Rate: 5.7 cfs • Peak 100 -year Flow Rate: 10.7 cfs Possible Alternatives: The following alternatives are available to correct the drainage problem at this site: • 1. We have been working with the home builder to fix the drainage problem at this site. This is being accomplished through the building permit process. The solution proposed by the builder is to excavate a small pond area to replace the depression area in the southwest corner of the lot. It is anticipated that the construction costs associated with this work will be approximately $1,000. The builder has placed $1,500 in an escrow account to cover this work once the area dries out in the spring. Recommendation: It is recommended that this problem area be categorized as a "Public Safety and Health" area (Category 1) since the overtopping of Eureka Road, if it occurs in the winter, could result in ice on the road. The City is working with the builder to construct these improvements to minimize the potential for flooding across Eureka Road. This situation would typically be categorized as a private drainage matter, but, because of the hazard potential, is moved to Category 1. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 32 WSB Project No. 1459 -04 Problem Area Number 27— 5840 Eureka Road Description of Problem: This property has experienced a wet basement after the two large rainfall events this fall. The property owner contends that this is a result of a new culvert that was installed under Eureka Road, which conveys runoff to the drainage swale located along the south edge of this property. This swale discharges to the wetland located west of this property. The homeowner believes that removal of debris at the outlet of this wetland would eliminate his problem. A cursory review indicates that the elevation of the outlet is approximately six feet below the existing ground elevation adjacent to his house. Since the basement is depressed approximately two feet, it appears that this is a groundwater related problem rather than a surface water runoff problem. It is unlikely that removing the debris, which is approximately six to twelve inches deep at the outlet, would greatly decrease the water level at the wetland. Hydrologic Information: • Tributary Area: 39.4 ac (direct), 55.9 ac (direct and indirect) • Impervious Surface: 38% • Peak 10 -year Flow Rate: 6.4 cfs* • Peak 100 -year Flow Rate: 7.0 cfs* * Flow rates based on existing CSMP model for culvert located upstream of this property. Possible Alternatives: In order to address flooding at this site, a new outlet for this basin would have to be constructed at a lower elevation. Storm sewer improvements for this area would involve constructing a trunk storm sewer system that would be deeper than the existing conveyance system of culverts, pipes, and ditches. This new trunk sewer would discharge to the large wetland complex downstream of Eureka Road. There will most likely be some amount of wetland mitigation required as a result of lowering the water level of this basin. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the problem appears to be related to a ground water level. A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 33 WSB Project No. 1459 -04 • Problem Area Number 28 — 5600 Wedgewood Drive Description of Problem: There has been standing water at the Regional Trail and that it is higher than usual. It is creating an annoying odor. The homeowner is also concerned about the potential for his house flooding. An emergency overflow elevation for this area is approximately two feet lower than that ground adjacent to the house. This overflow elevation is located approximately 300 feet west of Wedgewood Lane. Hydrologic Information: • Tributary Area: 1.1 ac • Impervious Surface: 14% • Peak 10 -year Flow Rate: 2.5 cfs • Peak 100 -year Flow Rate: 4.5 cfs Possible Alternatives: The following alternatives are available to correct the drainage problem at this site: 1. Do nothing. The house is not in danger of flooding from surface waters since there is an adequate overflow section. • 2. Provide outlet through existing overflow route. A positive outlet could be established by dredging the ditch deeper through the existing overflow area to the west. This work could be done by the Hennepin County Regional Trail Authority since the area is within their Right -of -Way. It would result in significant tree loss. The area with the standing water has been identified as a wetland, so eliminating all standing water would require mitigation to replace the lost wetland. It is anticipated that the construction costs associated with this work will be approximately $18,000. 3. Construct an outlet to the Wedgewood Drive storm sewer that is being proposed for construction in 2006. It is anticipated that the construction costs associated with this work will be approximately $156,000. This cost could be reduced if the outlet is constructed as part of the up- coming Wedgewood Drive road reconstruction project. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5). No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. Since the area in question also involves the Hennepin County Regional Trail Authority, the City has contacted them in an effort to assist with the solutions to the standing water. However, this • effort would result in the loss of many trees. The removal of these trees would not require replacement if the work is done as part of a City project. Analysis of Drainage Problem Areas within the City of Shorewood January 23,1006 Shorewood, Minnesota Page 34 WSB Project No. 1459 -04 Problem Area Number 29 — 26395 Peach Circle Description of Problem: The property owner at this location is concerned with the amount of standing water located adjacent to the Hennepin County Regional Trail. The water backed up during the recent storm events and flooded their backyard. They have also had flooding in the basement that was due to a failed sump pump. The emergency overflow elevation for this area is approximately one foot lower than that ground adjacent to the house. This overflow elevation is located approximately 600 feet east of Strawberry Lane. Hydrologic Information: • Tributary Area: 2.7 ac • Impervious Surface: 10% • Peak 10 -year Flow Rate: 5.6 cfs • Peak 100 -year Flow Rate: 10.4 cfs Possible Alternatives: The following alternatives are available to correct the drainage problem at this site: • Do nothing. The house is not in danger of flooding from surface waters since the overflow section is lower than the low building opening of the residence. However, more • freeboard would be preferred. 2. Provide a positive outlet through the existing overflow route. This outlet could be established through the existing overflow area by dredging the ditch deeper. This work could be done by the Hennepin County Regional Trail Authority since the area is within their Right -of -Way. It would result in significant tree loss. These trees would not have to be replaced, but replacement would result in a project that is more acceptable to surrounding residents. It is anticipated that the construction costs associated with this work will be approximately $28,000, excluding tree replacement. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. Since the area in question also involves the Hennepin County Regional Trail Authority, the City has contacted them in an effort to assist with the solutions to the standing water. is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 35 WSB Project No. 1459-04 • Problem Area Number 30 — 23930 Yellowstone Trail Description of Problem: This property is immediately east of 23980 Yellowstone Trail. The description of the problem, hydrologic information and possible alternatives are the same as those outlined in Problem Area Number 24. It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that an outlet from Mary Lake be constructed as part of the Minnetonka Drive storm sewer improvement project. • is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 36 WSB Project No. 1459 -04 Problem Area Number 31— 24735 Glen Road • Description of Problem: During recent storm events, the backyard area has filled up with water. When I visited the area on the 13` of October, the water had receded. The property owner claims to have lost $25,000 worth of landscaping improvements in the past at this property. This area has been studied as part of the Glen Road Problem Area Report, which was originally completed by WSB & Associates, Inc. in October of 2001. This project was not completed due to resistance by several property owners. Since that time, there have been storm sewer improvements constructed as part of the CSAH -19 Project. Based on these improvements, the previously proposed plan no longer is valid. However, the hydrology of this problem area is essentially unchanged in the vicinity. Hydrologic Information: • Tributary Area: 16.4 ac* • Impervious Surface: 26 %* • Peak 10 -year Flow Rate: 34.9 cfs ** • Peak 100 -year Flow Rate: 61.1 cfs ** *Based on model developed for CSMP * *Peak runoff rate represents runoff to low point at problem area. Possible Alternatives: • There is an outlet for this area proposed as part of the Amlee Road Reconstruction. The outlet will be constructed in the northeast corner of the lot and at an elevation low enough to convey runoff from the lower area at the back of the property. This outlet could be extended to the south to convey runoff from the low point if desired by the property owner. However, an easement will be required over all pipes within this property. It is anticipated that the construction costs associated with this work will be approximately $82,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) However, since this area has been an ongoing problem area, the City is in the process of designing plans for the construction of an outlet for this problem area, provided easements can be obtained. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 37 WSB Project No. 1459-04 • Problem Area Number 32 — 5770 Smithtown Way Description of Problem: The property owner contacted the City concerned about a "river" running through her yard. The "river" was caused by runoff from a designed drainage swale that outlets a wetland area behind this development. The swale flowing through conveys runoff around the houses, down the common lot line, and into a rock -lined channel where it is then conveyed the Smithtown Road storm sewer. The property owner claims that the increased runoff is a result of the construction on the new house at 5835 Eureka Road. Hydrologic Information: • Tributary Area: 18.5 ac (direct), 74.4 ac (direct and indirect) • Impervious Surface: 38% • Peak 10 -year Flow Rate: 36.5 cfs* • Peak 100 -year Flow Rate: 59.1 cfs* * Flow rate on based existing CSMP model for downstream outlet at pond adjacent to Smithtown Way. Possible Alternatives: • There is no alternative identified for this problem area as the system appears to be functioning as designed. All runoff is being contained in the drainage and utility easements. A review of these easements indicates that they are located along the back lot line for a width of approximately 51 feet at the west edge of the property. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the runoff conveyed through this property is contained within the existing drainage and utility easement. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 38 WSB Project No. 1459 -04 Problem Area Number 33 — 26275 Smithtown Road Description of Problem: The property owner called concerned that the culverts under Smithtown Road were partially plugged. During a visit to this area, it was observed that the entrance to one culvert was mostly plugged with debris. The other culvert had sufficient capacity to convey the runoff under Smithtown Road. A review of the City's one foot contour information indicates that Smithtown Road would overtop before the house at 26275 Smithtown Road would become inundated. Hydrologic Information: • Tributary Area: 44.5 ac (direct), 25 1. 5 ac (total tributary area) • Impervious Surface: 43% • Peak 10 -year Flow Rate: 63.4 cfs* • Peak 100 -year Flow Rate: 92.6 cfs* *Flow rates based on CSMP model. Road will not overtop during 100 - year event. Possible Alternatives: • No further work is required at this area, except regular maintenance to clean debris from the culvert entrances. • Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. Analysis of Drainage Problene Areas within the City of Shorewood January 23, 1006 Shorewood, Minnesota Page 39 WSB Project No. 1459 -04 • Problem Area Number 34 — 5900 Afton Road Description of Problem: The property owner has expressed concern about the amount of runoff that is conveyed through his backyard from his neighbor's property. The grading adjacent to the structure is adequate, with positive drainage away from the foundation. The runoff is conveyed through a small swale located approximately at the location of the homeowner's fence. The runoff is generated from a small tributary area, comprised of a portion of two neighboring lots. In addition to this concern, the property owner also expressed concern about several small maintenance items associated with the storm sewer for Smithtown Road. These include the following: a) There is a sinkhole adjacent to a catch basin immediately west of Afton Road. This is located in the south ditch of Smithtown Road. b) There is standing water on Afton Road after large rainfall events. c) There are additional sinkholes in the south ditch, east of Afton Road. This suggests there may be damage to the bands connecting the culvert. Hydrologic Information: • Tributary Area: 0.5 ac • • Impervious Surface: 14% • Peak 10 -year Flow Rate: 1.3 cfs • Peak 100 -year Flow Rate: 2.3 cfs Possible Alternatives: The homeowner may wish to consider regarding his lot to provide a more defined conveyance route for runoff through his backyard, further from his foundation. In order to address the maintenance concerns along Smithtown Road, it is recommended that the catch basin and culverts be repaired and the sinkholes backfilled. To reduce the potential for standing water on Afton Road, it is recommended that the grassed areas adjacent to the street be lowered so that the road is higher than that ditch. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance With No City Responsibility" area (Category 5). A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. The maintenance items associated with this problem area will be added to the maintenance list • that has been developed while discussing drainage concerns with residents and by observing problems during site visits. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 40 WSB Project No. 1459 -04 Problem Area Number 35 — 5790 Smithtown Way Description of Problem: The homeowner has a concern about the amount of runoff flowing through her backyard. She believes the problem is created by the construction of the new house 5835 Eureka Road. A review of the City's records indicates that there is a drainage and utility easement located in the backyard of this property. During the large October rainfall event, it was noted that the low spot at 5815 Eureka Road (See Problem Area Number 26) had standing water that backed up and over - topped Eureka Road. This water was conveyed through the backyards to this property. However, it does appear that the runoff was contained within the drainage and utility easement. Hydrologic Information: • Tributary Area: 1.5 ac • Impervious Surface: 24% • Peak 10 -year Flow Rate: 4.0 cfs • Peak 100 -year Flow Rate: 6.8 cfs Possible Alternatives: This problem area does not require any additional work as the runoff is conveyed within drainage and utility easements. The standing water and subsequent over - topping of Eureka Road is being addressed through the building permit process as discussed in the report for Problem Area Number 26. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. The City will be working with the house builder to reduce the potential for runoff over - topping Eureka Road. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 41 WSB Project No. 1459 -04 • Problem Area Number 36— 27475 Pine Bend Description of Problem: The property owner called complaining of a "river" running through her backyard. This appears to be an ongoing problem. The basement of the property is wet, but this appears to be caused by a high ground water table. The City did install a catch basin and grade a small swale along the property line to convey water away from the property. This was done in either 2001 or 2002. Hydrologic Information: • Tributary Area: 8.4 ac • Impervious Surface: 13% • Peak 10 -year Flow Rate: 13.0 cfs • Peak 100 -year Flow Rate: 24.2 cfs Possible Alternatives: The following alternatives are available to correct the flooding problem at this site: 1. Do nothing. This problem does not appear to be related to surface water runoff as there is an existing swale to convey surface water flows through the property. The catch basin that was installed consisted of a perforated riser, which would lower the ground water • table if the soils adjacent to the house were porous enough to convey water. 2. Construct a storm sewer system from west of Howards Point Road through the property. Although the swale is located on a private property, it does convey runoff from several lots upstream. It is possible to construct a system at a lower elevation, but this would result in the removal of several mature trees. 3. Since this is a ground water issue, the homeowner may wish to consider a more comprehensive foundation drain tile system and sump pump. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the problem appears to be related to a high ground water level. A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. is Analysis of Drainage Problem Areas within the City of Shorewood January 13,1006 Shorewood, Minnesota Page 42 WSB Project No. 1459 -04 Problem Area Number 37-23950 Elder Turn . Description of Problem: The property owner is concerned with the high water level in Mary Lake. This residence is south of the property at 23955 Clover Lane. The description of the problem, hydrologic information, and possible alternatives are the same for this property as those outlined for Problem Area Number 25. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that an outlet from Mary Lake be constructed as part of the Minnetonka Drive storm sewer improvement project. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 43 WSB Project No. 1459 -04 • Problem Area Number 38 — 23075 State Hijzhway 7 (Control House) Description of Problem: The owner of this commercial property initially contacted the City with a concern about a partially blocked culvert located in the roadside ditch downstream of this property. After review of property boundaries, it was determined that the constriction and the ditch block downstream were a result of an abandoned right -of -way. Mn/DOT maintenance crews have removed the old culvert and restored disturbed areas in the ditch downstream if the Control House. No record drawing information was available to verify the location of storm sewer in this area. However, there is a large pipe that discharges to the ditch north of the Control House driveway. The alignment of this culvert is not known at this time. After the constriction was removed, the property owner again contacted the City to express concern over the amount of gravel that had eroded upstream and deposited on his driveway. Hydrologic Information: • Tributary Area: 0.4 ac • Impervious Surface: 35% • Peak 10 -year Flow Rate: 1.2 cfs • Peak 100 -year Flow Rate: 2.1 cfs • Possible Alternatives: The following alternatives are available to reduce the potential for eroded materials being deposited on the driveway of the Control House property: 1. Construct storm sewer along Chaska Road. This would allow runoff to be conveyed in the storm sewer pipe rather than on the roadway shoulder. This would reduce the potential of gravel from the shoulder being eroded downstream. It is anticipated that the construction costs associated with this work will be approximately $18,000. 2. Construct catch basin over existing storm sewer. This would convey runoff, and sediment, from the road under the driveway. Additional investigation would have to be done to determine exactly where the storm sewer is located in this area. It is anticipated that the construction costs associated with this work will be approximately $2,500. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is recommended that additional investigation be undertaken as to the exact location of the storm sewer outletting into the Chaska Road ditch adjacent to the Control House. This investigation will be necessary to determine the most effective storm sewer option available to • minimize the amount of sediment deposited on the driveway entrance to the Control House. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 44 N'SB Project No. 1459-04 Problem Area Number 39 — 23895 /23905 Elder Turn • Description of Problem: This property is located across the street from the property located at 23950 Elder Turn (Problem Area Number 37.) The description of the problem, the hydrologic information, and possible alternatives are the same for this property as those outlined for Problem Area Number 25. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. It is also recommended that an outlet from Mary Lake be constructed as part of the Minnetonka Drive storm sewer improvement. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 45 WSB Project No. 1459 -04 • Problem Area Number 40 —19660 Silver Lake Trail Description of Problem: The property owner contacted the City concerned about the high water level in the wetland behind her house. She had also reported that the road was washed out, but it was determined that what she meant was only that the water had overtopped the road. Hydrologic Information: • Tributary Area: 20.2 ac (direct), 72.8 ac (total tributary area)* • Impervious Surface: 35% • Peak 10 -year Flow Rate: 5.0 cfs ** • Peak 100 -year Flow Rate: 5.8 cfs ** *Based on model developed for CSMP ** Estimated flow rates based on capacity of culvert under Sweetwater Curve. Possible Alternatives: This area is located on private property. Therefore, no work will be done by the City on this • property. However, if the homeowner wishes to regrade the lot, they could do so. Any fill in excess of 100 cubic yards would require a Conditional Use Permit from the City. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 46 WSB Project No. 1459 -04 Problem Area Number 41— 5775 Smithtown Wav Description of Problem: This property is adjacent to 5790 Smithtown Way. The description of the problem, hydrologic information, and possible alternatives are the same for this property as those outlined for Problem Area Number 35. The homeowner has a concern about the amount of runoff flowing through her backyard. She believes the problem is created by the construction of the new house 5835 Eureka Road. A review of the City's records indicates that there is a drainage and utility easement located in the backyard of this property. During the large October rainfall event, it was noted that the low spot at 5815 Eureka Road (See Problem Area Number 26) had standing water that backed up and over - topped Eureka Road. This water was conveyed through the backyards to this property. However, it does appear that the runoff was contained within the drainage and utility easement. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) • A letter informing the homeowner of this will be mailed, but no further analysis of this site will • be made without direction from the City. The City will be working with the house builder to address the potential for runoff over - topping Eureka Road. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 47 WSB Project No. 1459-04 • Problem Area Number 42 — 5970 Strawberry Lane Description of Problem: This property owner is concerned about standing water in the neighbor's yard and along his common lotline. He would like his neighbor to the north to install a culvert under his driveway so that runoff will be conveyed to the existing wetland north of the neighbor's property. Hydrologic Information: • Tributary Area: 4.7 ac • Impervious Surface: 19% • Peak 10 -year Flow Rate: 9.5 cfs • Peak 100 -year Flow Rate: 17.0 cfs Possible Alternatives: The following alternatives are available to reduce the potential for nuisance flooding at this site: 1. Do nothing. There is an emergency overflow located at the west end of the property that would allow runoff to overflow to a pond in back of the property prior to flooding the structure located at 5970 Strawberry Lane. • 2. Installation of a culvert in the neighbor's property. This could be done, but it appears there would be a minimal amount of hydraulic head over the culvert to convey water to the north. It appears the area most likely would remain wet after large storm events unless the culvert could be installed at a lower elevation and the adjacent ground graded to drain toward the culvert. Since this is a relatively large area that is very flat, this does not appear to be a very practical solution. It is anticipated that the construction costs associated with this work will be approximately $4,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Anatt sis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 48 WSB Project No. 1459 -04 Problem Area Number 43 — 20458/ 20456 / 20454 / 20452 120450 Knightsbridge Road • (Amesbury Townhomes) Description of Problem: This problem area is immediately downstream of an existing wetland. During the storm events, the wetland filled up until it reached its over - topping elevation. Once this happened, the runoff that normally would have been contained within the basin was conveyed down the hill through the drainage swale adjacent to the townhomes and into a culvert located under Knightsbridge Road. The capacity of this storm sewer system does not appear to be adequate to convey the runoff rate from the area. Therefore, the townhomes were flooded. A subdivision of existing lots in the upstream reach of this subwatershed was under construction when the flooding occurred. Hydrologic Information: • Tributary Area: 6.5 ac (reduced to 5.6 ac with new construction upstream) • Impervious Surface: 17% (based on proposed conditions) • Peak 10 -year Flow Rate: 12.6 cfs* • Peak 100 -year Flow Rate: 22.4 cfs* *Peak rates based on proposed conditions Possible Alternatives: • The following alternatives are available to reduce the potential for flooding at this site: Provide a positive outlet from the wetland located on the common lot line. By providing a positive outlet, the storage in this basin can be used to reduce peak rates. A possible secondary benefit would be that the outlet pipe could be constructed so that the runoff is conveyed in the pipe rather than through the overland Swale adjacent to the townhomes. Increasing the size of the wetland and/or constructing a berm across the natural overflow outlet could create additional storage. This work would have to be coordinated with the Minnehaha Creek Watershed District so that the requirements of the Wetland Conservation Act are met. It is anticipated that the construction costs associated with this work will be approximately $12,000. 2. A larger pipe could replace the 18 -inch RCP with greater conveyance capacity. Consideration should be given to providing a larger pipe that is less susceptible to plugging by debris. It is anticipated that the construction costs associated with this work will be approximately $56,000. 3. Do nothing. The Homeowner's Association could monitor the wetland level and pump the water down to provide some storage for larger runoff events. It should be noted that this might not eliminate flooding potential, depending on the amount of pumping that can be achieved between storm events. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 49 WSB Project No. 1459 -04 • Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) A letter will be sent to the Homeowners Association recommending that they contact their residents to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 50 WSB Project No. 1459 -04 Problem Area Number 44 — 6045 Burlwood Court Description of Problem: This property owner called to complain about standing water located between her house and the neighbor to the west. They are also concerned about a bad odor, presumably from standing water. During the November 8, 2005 site visit, no standing water was observed. Hydrologic Information: • Tributary Area: 1.7 ac • Impervious Surface: 13% • Peak 10 -year Flow Rate: 3.7 cfs • Peak 100 -year Flow Rate: 6.8 cfs Possible Alternatives: The following alternatives are available that may reduce the potential for standing water in this area: • 1. Do nothing. There does not appear to be flood potential. Based on the City's one foot contour information, the emergency overflow to Burlwood Court is approximately 975. The homes adjacent to this low point have a low building opening of greater than 976 (6065 Burlwood Court) or 979.5 (6045 Burlwood Court), which provides approximately • one foot of freeboard. 2. Construction of an outlet to the Burlwood Court storm sewer would minimize standing water at this location. It is anticipated that the construction costs associated with this work will be approximately $11,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 51 WSB Project No. 1459 -04 • Problem Area Number 45 — 5480 Carrie Lane Description of Problem: This property owner contacted the City for assistance after experiencing minor erosion on her property after the heavy rainfall event in September. The property owner wanted to use salvaged landscape rock that had washed off the entrance area to Carrie Lane. Carrie Lane is a private road. Therefore, the City is not responsible for maintenance of this road. Hydrologic Information: • No hydrologic information was gathered nor an analysis made as this is a private matter. Possible Alternatives: The homeowner desired to use the salvaged material, although it was recommended that larger rip -rap or other channel stabilization measures may be necessary due to the high velocity of runoff coming through the culvert under their driveway. Since this was a private system entirely on private property, it was determined that the homeowner could proceed at their own risk. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 52 WSB Project No. 1459 -04 Problem Area Number 46 — 5480 Teal Circle Description of Problem: This property owner contacted the City concerned that a neighbor had dammed up the channel with concrete blocks, and the blocks were causing erosion to the channel banks. The resident also expressed concern that increased runoff due to a pond south of the Hennepin County Regional Trail being filled in over time with sediment. Hydrologic Information: • Tributary Area: 20 ac • Impervious Surface: 30% • Peak 10 -year Flow Rate: 19.2 cfs* • Peak 100 -year Flow Rate: 24.8 cfs* * Peak flow rates based on model developed for CSMP. Possible Alternatives: City crews removed the concrete blocks on November 2, 2005. Dredging of the pond could be accomplished when the Harding Lane improvements are constructed (see Problem Area 22.) Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) A letter informing the homeowner of this will be mailed, but no further analysis of this site will be made without direction from the City. is • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 53 WSB Project No. 1459 -04 • Problem Area Number 47— 6060 Strawberry Lane Description of Problem: This property owner has standing water in his yard and he would like to grade the road ditch towards the Regional Trail to provide a positive outlet for standing water in his front yard. It appears the previous homeowner had placed fill in a portion of the ditch. He does not want to lose trees in his back yard. Therefore, he is not receptive to having the Regional Trail Authority provide a ditch along their trail corridor. An outlet culvert is located under Strawberry Lane that conveys runoff in the south ditch of the Regional Trail from the west side of Strawberry Lane to the east side. This water then is conveyed into Freeman Park. Hydrologic Information: • Tributary Area: 0.3 ac* • Impervious Surface: 30% • Peak 10 -year Flow Rate: 1.0 cfs • Peak 100 -year Flow Rate: 1.6 cfs *Hydrologic information listed is for area directly tributary to road side ditch. The total area tributary to the Regional Trail ditch is significantly • larger. Possible Alternatives: In order to minimize the amount of standing water that is present within this property, the old drainage ditch could be dredged out along the Regional Trail. In lieu of this, the property owner mentioned that he would dig out a small channel to drain the water out. The property owner also asked permission to dig out the road ditch adjacent to his property. It is anticipated that the construction costs associated with this work will be approximately $1,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. The letter will also indicate to the property owner that the maintenance of the ditch adjacent to Strawberry Lane within his property limits would be acceptable, provided the ditch was cleaned out but not lined with rock. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 54 WSB Project No. 1459 -04 Problem Area Number 48 — 5820 Eureka Road • Description of Problem: This property is located across the street from 5815 Eureka Road. The description of the problem, hydrologic information, and possible alternatives are the same as those outlined for Problem Area Number 26. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6.) No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. The City is working with the builder to construct improvements at 5815 Eureka Road, which will minimize the potential for flooding across Eureka Road. • • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 55 WSB Project No. 1459 -04 • Problem Area Number 49 — 20480 Radisson Road Description of Problem: The resident contacted the City to express concern about the amount of runoff from Radisson Road. It appears that the runoff was conveyed over his driveway and across his lawn, where it may have displaced a portion of a keystone block retaining wall. The wall is approximately six to seven feet high and does not appear to have any tiebacks. This lack of tiebacks may have contributed to the displacement of the wall. Hydrologic Information: • Tributary Area: 0.4 ac • Impervious Surface: 23% • Peak 10 -year Flow Rate: 1.2 cfs • Peak 100 -year Flow Rate: 2.0 cfs Possible Alternatives: The following alternatives are available to correct the drainage problem at this site: 1. Install curb and gutter along Radisson Road when the street is reconstructed. It is anticipated that the construction costs associated with this work will be approximately • $17,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with Limited Public Responsibility" area (Category 4) since a portion of the runoff comes from City Right -of- Way. The area below the retaining wall is a good location for a storm water treatment pond. If the City desires to upgrade Radisson Road with curb and gutter in the future, consideration should be given to obtaining an easement in this area for a storm water treatment pond. is Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 56 WSB Project No. 1459 -04 Problem Area Number SO — 6120 Riviera Lane • Description of Problem: The property owner contacted the City to express concern over standing water at the end of his driveway. This area is in the low point of Riviera Road, adjacent to a wetland. The standing water is caused by the crown of the road trapping water in this area. Hydrologic Information: • Tributary Area: 4.4 ac • Impervious Surface: 13% • Peak 10 -year Flow Rate: 6.8 cfs • Peak 100 -year Flow Rate: 12.7 cfs Possible Alternatives: The following alternatives are available to reduce the nuisance flooding in this area: 1. Regrade Riviera Lane road surface. It is anticipated that the construction costs associated with this work will be approximately $14,000. Substantial cost savings would be realized if this work was to be completed as a part of the reconstruction of the Riviera Lane road surface. Recommendation: It is recommended that this problem area be categorized as a "Public Nuisance" area (Category 3.) The project is not cost - effective unless it is done as part of an overall reconstruction of Riviera Lane. Therefore, it is recommended that the project not be undertaken until the City reconstructs the road surface at Riviera Lane. A letter will be sent to the property owner informing them of this, but no further analysis will be made without direction from the City. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 57 WSB Project No. 1459 -04 • Problem Area Number 51— 26505 Maple Avenue Description of Problem: The property owner contacted the City to express concern about standing water in their yard. Their property is an inside lot with no direct access to the street, with the exception of their driveway through Maple Avenue. Hydrologic Information: • Tributary Area: 2.0 ac* • Impervious Surface: 15% • Peak 10 -year Flow Rate: 5.1 cfs • Peak 100 -year Flow Rate: 9.2 cfs *Hydrologic information listed is for area directly tributary to low spot between houses. The entire area is low and has a larger total tributary area. Possible Alternatives: Since this a low land - locked area, the only alternative would be to construct a large trunk storm sewer to provide a positive outlet for this property. The trunk sewer could also serve as a • conveyance system for Problem Area Number 47 and Problem Area Number 29. It is anticipated that the construction costs associated with this system will be approximately $215,000. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5.) A letter will be sent to the resident recommending that he contact his neighbors to discuss alternatives and that they work together to provide a solution to the problem. No further analysis will be undertaken by WSB on this problem area unless directed by the City to do so. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 58 WSB Project No. 1459 -04 III. SUMMARY AND RECOMMENDATIONS • Generally, the City's drainage issues can be classified as nuisance flooding, with a few exceptions. Tables I — 6 summarize the problem areas by each of the six categories outlined at the beginning of this report. Of the 51 problem areas, only three are recommended for immediate correction. These are the areas listed under Category 1, which may pose a threat to public safety if left unchecked. Table 1 outlines the problem areas that may impact the public health or safety (Category 1). It is anticipated that flooding risks at the two areas can be reduced through construction projects with an estimated cost of $29,000 to $44,000. Table 2 is provided as a place holder should any new areas be discovered in which the problem area will have a negative impact on the residents as a whole (Category 2.) Table 3 shows the problem areas that are a public nuisance (Category 3.) It is anticipated that flooding risks at the two areas can be reduced through construction projects with an estimated cost of $22,000 to $33,000. The flooding problem at Lake South Auto has already been addressed and the other area is a nuisance problem that does not pose an immediate threat to any buildings. Therefore, it is recommended that these projects be deferred until a time the projects could be combined with other work in the vicinity. Table 4 outlines the problem areas that either involve a site where the problem is caused, at least partially, by runoff generated within the City's Right -of -Way, or where a large drainage area is • causing a problem to a small area, limiting a single resident to easily solve the problem by themselves (Category 4.) It is anticipated that that flooding risks at these areas can be reduced through construction projects with an estimated cost of $216,300 to $916,200. It should be noted that costs vary greatly dependent upon the scope and solutions of the projects noted. Design projects would have to be undertaken to determine a more specific detail of the costs. Of the areas within this category, it is recommended that the areas identified as a flooding threat to any buildings should be considered first. Table 5 outlines the problem areas that either involve a site where the problem is caused by runoff generated from private property or where a small area is involved (Category 5.) It is anticipated that that flooding risks at these areas can be reduced through construction projects with an estimated cost ranging from $345,400 to $703,100. Of these areas, it is recommended that the areas identified as a flooding threat to any buildings should be considered first. These areas are highlighted on the table, and represent a cost of $69,000. Table 6 outlines the problem areas that, after our investigation, were deemed to not be problems Category 6.) These areas either were entirely private issues on a single property, maintenance issues addressed by City crews, or problems being addressed through the City's building permit process. There were five areas in which a resident perceived "flooding," but after further review, it was determined that the runoff was contained to portions of their property, our adjacent properties, that were covered by Drainage and Utility Easements. No further work is recommended for these areas, other than sending a letter to the resident explaining our findings. Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 59 WSB Project No. 1459 -04 • In order to address the problem areas summarized in Tables 1— 4, the estimated costs range is between $267,300 and $993,200. Funding: Currently, the City has in place a stormwater fee. As design alternatives are considered, utilization of the stormwater fees, in conjunction with special assessments for benefiting areas, will need to be considered. • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota Page 60 WSB Project No. 1459 -04 • TABLES 0 0 Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota WSB Project No. 1459 -04 Table 6 Summary of Problem Areas Categorized as "No Further Action Required" Areas (Category 6) PA # Name Address Opinion of Probable Cost Notes 4 Jim Cradit 5925 Gal in Lake Rd N/A Problem addressed through building permit process 8 1 Kathy Kucera 20955 Ivy Lane N/A Private matter on individual lot 10 Mike Messina 25720 & 25722 Wildrose Ln N/A Property owner has addressed problem 15 Frontier Electric 800 Water Street N/A Problem addressed through other governmental entities 19 Craiq Johnson 26025 Birch Bluff Rd N/A Problem addressed by City crews 27 John Majestic 5840 Eureka Rd N/A This appears to be related to a high groundwater level 32 Barb Richman 5770 Smithtown Way N/A Not really a problem - runoff contained within Drainage & Utility Easement 33 Glen Gillund 26275 Smithtown Rd N/A Problem addressed by City crews 35 Shelly McGinnis 5790 Smithtown Way N/A Not really a problem - runoff contained within Drainage & Utility Easement 36 Ann Seymour 27475 Pine Bend N/A Previously addressed by City - appears to be related to a high groundwater level 40 Melena Gross 19660 Silver Lake Tr N/A Not really a problem - wetland contained within Drainage & Utility Easement 41 Darcy Berta noli 5775 Smithtown Way N/A Not really a pr oblem - runoff contained within Drainage & Utility Easement 45 Carol McClure 5480 Carrie Ln N/A Private matter on individual lot 46 Pat Arnst 5480 Teal Circle N/A Problem addressed by City crews 48 Mark McClure 5820 Eureka Rd N/A Problem will be addressed through building permit process 1/18/2006 Tables Table S Summary of Problem Areas Categorized as "Private Nuisance with No City Responsibility" Areas (Category 5) PA # Name Address Opinion of Probable Cost Notes 6 Ketti & Mike Histon 26220 Wild Rose Ln $6,000 to $13,000 House flooded 43 Amesbury Townhomes Tom Maple $12,000 to $56,000 Townhouses flooded 31 Diane Buranen 24735 Glen Rd $65,000 to $82,000 Long-term problem 22 Pat Brown 5635 Harding Ln $8,900 to $87,000 Long-term problem 23 Adam McArthur 5615 Harding Ln see note Combined with PA 22 2 Kim Culp 6100 Apple Rd $12,000 to $16,000 9 Greg Johnson 4980 Suburban Dr $4,000 to $8,000 12 Nathan Shanklin 21165 Mtka Blvd $4,000 to $12,000 14 Ann Levenworth 28070 Woodside Rd $1,700 to $5,000 46 Larry Reid 27780 Island View Rd $4,500 to $7,800 28 Greg Sochko 5600 Wed ewood Dr $18,500 to $156,000 More cost effective if done with overall project when Wed ewood is reconstructed 29 Kizilos -Cliff 26395 Peach Circle $22,000 to $27,000 34 Bob Castellano 5900 Afton Rd $1,700 to $2,100 42 Brian Lieffers 5970 Strawberry Lane $3,300 to $4,200 44 Ellen Jordano 6045 Buriwood Ct $9,000 to $11,000 47 Don Johnson 6060 Strawberry Lane $800 to $1,000 51 Eileen Koehnen 26505 Maple Ave $172,000 to $215,000 Totals 1$345,400to$703,100 NOTE: Projects are listed in recommended order of priority. Highlighted areas represent the areas that experienced flooding of buildings. 1/18/2006 Tables • • • • • • Table 4 Summary of Problem Areas Categorized as "Private Nuisance with Limited City Responsibility" Areas (Category 4) PA # Name Address Opinion of Probable Cost Notes 24 Kay Marie 23980 Yellowstone Tr $40,000 to $207,000 Cost will be less if constructed with Minnetonka Dr. storm sewer improvements 25 lDon Chinander 23955 Clover Ln see note Combined with PA 24 30 Igor Zotov 23930 Yellowstone Tr see note Combined with PA 24 37 Anna Williams 23950 Elder Turn see note Combined with PA 24 39 Pat Niemi 23905/23895 Elder Turn see note Combined with PA 24 1 Elizabeth Birkland 6180 Murray Hill Rd $2,000 to $31,000 7 Marilyn Miscivits 5925 Grant St $33,000 to $42,000 21 Dorothea Hanes 5915 Grant St see note Combined with PA 7 17 Leslie Huberty 23350 Academy $900 to $53,000 18 John Dean 6180 Chaska Rd $2,000 to $3,200 Home owner willing to do work 3 Minnetonka CC Maxwell Olson $120,000 to $533,000 Has potential for comprehensive "regional" system; phased construction possible 13 Russ Aldrich 4770 Lakeway Terrace $900 to $12,000 38 Dave Mueller 23075 State Hwy 7 $2,500 to $18,000 49 Doug Maxwell 20480 Radisson Road $15,000 to $17,000 I Totals J$216,300 to $916,200 NOTE: Projects are listed in recommended order of priority. Highlighted areas represent the areas that experienced flooding of buildings. 1/18/2006 Tables Table 3 Summary of Problem Areas Categorized as "Public Nuisance" Areas (Category 3) Opinion of PA # Name Address Probable Cost Notes 11 Lake South Auto Bill Kirchner $15,000 to $19,000 Building flooded 50 Jim McFarland 6120 Riviera $7,000 to $14,000 More cost effective if done as part of overall project when Riviera is reconstructed to 1/18/2006 Tables • 0 • • • • Table 2 Summary of Problem Areas Categorized as "Substantial Financial Impact to the City" Areas (Category 2) Opinion of PA # Name Address Probable Cost Notes No problem areas are cate ofted as "Substantial Financial Impact to the City" Totals 1/18/2006 Tables Table I Summary of Problem Areas Categorized as "Public Safety and Health" Areas (Category 1) PA # Name Address Opinion of Probable Cost Notes 5 Chris Farni 25360 Birch Bluff Rd $10,000 to $15,000 Contractor has been hired to do work insprin 20 Susan Neslund 22015 Stratford PI $18,000 to $27,000 Recommend contacting City of Chanhassen to discuss possibility of costs lit 26 Don Rogers 5815 Eureka Rd $1,000 to $2,000 Work to be done by Clark Kent Homes as condition of building permit 1 1 UiaiS I�Ly,UVU i X44,000 1/18/2006 Tables • • • • APPENDIX A Analysis of Drainage Problem Areas within the City of Shorewood Shorewood, Minnesota WSB Project No. 1459 -04 January 23, 2006 Appendix A Opinion of Probable Cost Problem Area 1 - 6180 Murray Hill Road A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $5,000.0 $5,000.0 2 Remove Bituminous Pavement 200 SY $5.0 $1,000.0 3 Salvage and Reinstall Base Course Aggregate 35 CY $12.0 $420.0 4 Excavation 20 CY $15.0 $300.0 5 Storm Sewer (15" RCP) 120 LF $40.0 $4,800.0 6 Catch Basins and Manholes 5 EA $1,250.0 $6,250.0 7 Bituminous Pavement 45 TN $150.0 $6,750.0 Subtotal $24,520. +25%Contingencie4 $6, 130.0 Tota $30,650.0 Preliminary Opinion of Probable Cost - Option 2 (Construct Berm on West Edee of Road) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $750.0 $750.0 2 Imported Borrow Material 45 CY $15.0 $675.0 3 Turf Establishment 200 SY $2.0 $400.0 Subtota $1,825.0 +25 %Contin encie $456.0 Totall $2,281.0 Preliminary Opinion of Probable Cost - Ootion 3 (Excavate a Drainage Swale Below Hill) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $1,250.0 $1,250. 2 Excavation 75 CY $8.0 $600.0 3 Turf Establishment 250 SY $2.0 $500.0 Subtota $2,350.0 +25 %Contin encie $588.0 Totall $2,938.0 r1 � J • 1/18/2006 PA 1 Appendix A • Opinion of Probable Cost Problem Area 2 - 6100 Apple Road • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Ooinion of Probable Cost - Option 1 (Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Storm Sewer (15" HDPE) 250 LF $25.00 $6,250.0 3 Catch Basins and Manholes 4 EA $750.00 $3,000.0 4 Restoration 1 LS $750.00 $750.0 Subtotal $12,500.0 +25 % Contingencies $3,125.0 Total $15,625.0 1118/2006 PA 2 Appendix A Opinion of Probable Cost Problem Area 3 - Minnetonka Country Club A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization I LS $25,000.00 $25,000.0 2 Excavation 15000 CY $12.00 $180,000.0 3 Storm Sewer (12" RCP) 600 LF $35.00 $21,000.0 4 Storm Sewer (15" RCP) 300 LF $40.00 $12,000.0 5 Storm Sewer (27" RCP) 2000 LF $85.00 $170,000.0 6 Catch Basins and Manholes 9 EA $1,250.00 $11,250.0 7 Turf Establishment 5 Ac $1,500.00 $7,500.0 Subtotal $426,750.0 +25 %Contin encies $106,688.0 Total $533,438.0 • • 1/1812006 I PA 3 Appendix A Opinion of Probable Cost Problem Area 5 - 25360 Birch Bluff Road • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Remove Existing Culvert I LS $800.00 $800.0 3 Furnish and Install 30" RCP -A 30 LF $100.00 $3,000.0 4 Pipe Bedding 20 TN $15.00 $300.0 5 Pavement Removal & Restoration 50 SY $100.00 $5,000.0 6 Sediment Removal at Edge of Lake 1 LS $500.00 $500.0 Subtotal $12,100.0 +25% Contingencies $3,025.0 Total $15,125.0 1/18/2006 PA 5 Appendix A Opinion of Probable Cost Problem Area 6 - 26220 Wild Rose Lane A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Seal low building openings) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization I LS $2,500.00 $2,500.0 2 Seal walkout door and lookout window 1 LS $7,500.00 $7,500. Subtotal $10,000. +25% Contingenciesi $2,500.0 Totall $12,500.0 Preliminary Opinion of Probable Cost - Option 2 (Excavate swale) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Excavation 130 CY $14.00 $1,820.0 3 Restoration 1 LS $750.00 $750.0 Subtotal $5,070.0 +25 %Contin encies $1,268.0 Total $6,338.0 • • • 1/18/2006 1 PA 6 Appendix A • Opinion of Probable Cost Problem Area 7 - 5925 Grant Street • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $3,500.00 $3,500.0 2 Remove Bituminous Pavement 200 SY $5.00 $1,000.0 3 Storm Sewer (12" RCP) 80 LF $35.00 $2,800. 4 Storm Sewer (15" RCP) 90 LF $40.00 $3,600.0 5 Storm Sewer (27" RCP) 70 LF $85.00 $5,950.0 6 Catch Basins and Manholes 5 EA $1,250.00 $6,250.0 7 Salvage and Reinstall Base Course Aggregate 35 CY $12.00 $420.0 8 1 Bituminous Pavement 45 TN $150.00 $6,750.0 9 Turf Establishment 1500 Sy $2.00 $3,000.0 Subtotal $33,270.0 +25% Contingencies $8,318.0 Total $41,5880 1/18/2006 PA 7 Appendix A Opinion of Probable Cost Problem Area 9 - 4980 Suburban Drive A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option l (Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Storm Sewer (8" HDPE) 60 LF $12.00 $720.0 3 Catch Basins and Manholes 2 EA $750.00 $1,500.0 4 Restoration I LS $500.00 $500.0 Subtotal $5,220.0 +25% Contingencies $1,305.0 Total $6,525.0 Preliminary Opinion of Probable Cost - Option 2 (Construct berm) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Imported Borrow Material 30 CY $25.00 $750.0 3 Restoration 1 LS $200.00 $200.0 Subtotal $3,450.0 +25% Contingenciesi $863.0 Totall $4,313.0 Preliminary Opinion of Probable Cost - Option 3 (Pave Driveway) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $800.00 $800.0 2 Subgrade Prep 1 LS $200.00 $200.0 3 Bituminous Pavement 35 TN $150.00 $5,250.0 Subtotal $6,250.0 +25 % Contingencies $1,563.0 Total $7,813.0 • • 1/18/2006 PA 9 Appendix A • Opinion of Probable Cost Problem Area 11 - 25575 Smithtown Road (Lake South Auto) C] • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization I LS $5,000.00 $5,000.0 2 Remove Bituminous Pavement 150 SY $5.0 $750.0 3 Salvage and Reinstall Base Course Aggregate 25 CY 1 $12.00 $300.0 4 lExcavation 50 CY $15.00 $750.0 5 Bituminous Pavement 35 TN $150.00 $5,250.0 6 Restoration I LS $3,500.00 $3,500.0 Subtotal $15,550.0 +25% Contingencies $3,888.0 Total $19,438.0 1/18/2006 PA 11 Appendix A Opinion of Probable Cost Problem Area 12 - 21165 Minnetonka Blvd. A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (install Flap Gate) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $1,200.00 $1,200. 2 Manhole with Flap Gate 1 EA $1,800.00 $1,800.0 3 Restoration 1 LS $250.00 $250.0 Subtotall $3,250.0 +25 % Contingencies $813.0 Totall $4,063.0 Preliminary Opinion of Probable Cost - Option 2 (Construct Parallel Storm Sewer) Item No. Description Quantity Unit Unit Cost Total I Mobilization 1 LS $2,500.00 $2,500.0 2 Storm Sewer (12" HDPE) 210 LF $24.00 $5,040.0 3 Catch Basins and Manholes 2 EA $750.00 $1,500.0 4 Restoration 1 LS $500.00 $500.0 Subtotal $9,540.0 +25% Contingencies $2,385.0 Total $11,925.0 • i s • 1/18/2006 PA 12 • Appendix A Opinion of Probable Cost Problem Area 13 - 4770 Lakeway Terrace • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Install New Castind Item No. IDescription I Quantity I Unit I Unit Cost I Total 1 New Casting 1 I LS I $750.Od $750.0 Subtotal $750.0 +25% Contin nci $188.0 Total $938.0 Preliminary Opinion of Probable Cost - Option 2 (Tip Road Surface To Drain to the East) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.0 $2,500.0 2 Remove Bituminous Pavement 100 SY $5.0 $500.0 3 Salvage and Reinstall Base Course Aggregate 20 CY $12.0 $240.0 4 Excavation 10 CY $15.0 $150.0 5 Bituminous Pavement 25 TN $150.0 $3,750.0 6 Insulation of Lift Staion and Foncemain 1 LS $2,500.0 $2,500.0 Subtotal $9,640.0 +25 % Contingence $2,410.0 Total $12,050.0 Preliminary Opinion of Probable Cost - Option 3 (Construct Berm on West Edge of Road) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization I LS $800.0 $800.0 2 Imported Borrow Material 25 CY $15.0 $375.0 3 Turf Establishment 100 SY $2.0 $200.0 Subtotal $1,375.0 +25% Contingencie $344.0 Totall $1,719.0 1/18/2006 PA 13 Appendix A Opinion of Probable Cost Problem Area 14 - 28070 Woodside Rd. A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Raise Area Adjacent to Downspout Entrance) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $300.00 $300.0 2 Grouted Riprap 8 CY $95.00 $760.0 3 Restoration 1 LS $300.00 $300.0 Subtotal $1,360.0 +25% Contingencies $340.0 Total $1,700.0 Preliminary Opinion of Probable Cost - Option 2 (Construct New Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $800.00 $800.0 2 Storm Sewer (12" HDPE) 80 LF $24.00 $1,920.0 3 Catch Basins and Manholes 1 EA $750.00 $750.0 4 Restoration 1 LS $500.00 $500.0 Subtotal $3,970.0 +25% Contingencies $993.0 Total $4,963.0 is • • 1/1812006 PA 14 Appendix A • Opinion of Probable Cost Problem Area 16 - 27780 Island View Rd. • .7 A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Construct New Draintile System) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $500.00 $500.0 2 Storm Sewer (8" HDPE) 300 LF $15.00 $4,500.0 3 Catch Basins and Manholes 3 EA $250.00 $750.0 4 Restoration 1 F LS $500.00 $500.0 Subtotal $6,250.0 +25% Contingencies $1,563.0 Total $7,813.0 Preliminary Opinion of Probable Cost - Option 2 (Construct Rain Garden) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $300.00 $300.0 2 Wet - tolerant plants 12 EA $250.00 $3,000.0 3 Restoration 1 LS $300.00 $300.0 Subtotal $3,600.0 +25% Contingencies $900.0 Total $4,500.0 1/18/2006 PA 16 Appendix A Opinion of Probable Cost Problem Area 17 - 23350 Academy Lane A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option I (Install New Casting) Item No. Description Quantity Unit Unit Cost Total I l NewCasting I LS $750.00 $750.0 Subtotal $750.0 +25% Contingencies $188.0 Total $938.00 Preliminary Opinion of Probable Cost - Option 2 (Excavate Ditch on South Side of Road) Item No. Description Quantity Unit Unit Cost Total I Mobilization I LS $800.00 $800.0 2 Excavation 15 CY $15.00 $225.00 3 Turf Establishment 40 Sy $2.00 $80.00 Subtotal $1,105.00 +25 %Contingencies $276.00 Totaq $1,381.00 Preliminary Opinion of Probable Cost - Option 3 (Lower Road and Install Curb & Gutter) Item No. Description Quantity Unit Unit Cost Total I Mobilization l LS $2,500.00 52,500.0 2 Remove Bituminous Pavement 800 SY $5.00 $4,000. 3 Salvage and Reinstall Base Course Aggregate 140 CY $12.00 $1,680.00 4 Excavation 80 CY $15.00 $1,200.00 5 1 Curb & Gutter 800 LF $8.00 $6,400.00 5 1 Bituminous Pavement 180 TN $150.00 $27,000.00 Subtotal $42,780.00 +25 %Contingencies $10,695.00 Total $53,475.00 • • • 1118/2006 1 PA 17 Appendix A • Opinion of Probable Cost Problem Area 18 - 6180 Chaska Road A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. • Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $800.00 $800.0 2 Excavation 100 CY $15.00 $1,500.0 3 Turf Establishment 120 SY $2.00 $240.0 Subtotal $2,540.0 +25% Contingencies $635.0 Total $3,175.0 • 1/18/2006 PA 18 Appendix A Opinion of Probable Cost Problem Area 20 - 22015 Stratford Road A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Ooinion of Probable Cost - Option 1 Item No. Description Quantity Unit Unit Cost Total I Mobilization I LS $5,000.00 $5,000. 2 Clearing and Grubbing 1 LS $2,000.00 $2,000.0 3 36" RCP 100 LF $90.00 $9,000. 4 Fumish and Install Manhole 6 LF $500.00 $3,000. 5 Salvage and Reinstall 36" FES 1 EA $2,500.00 $2,500.0 Subtotal $21,500.0 +25 %Contin encies $5,375.0 Total $26,875.0 Preliminary Opinion of Probable Cost - Option 2 Item No. Description Quantity Unit Unit Cost Total I Mobilization 1 LS $5,000.00 $5,000.0 2 Clearing and Grubbing 1 LS $2,800.00 $2,800.0 3 Fumish and Place Riprap 75 CY $80.00 $6,000.0 4 Type IV Geotextile Fabric 100 SY $2.00 $200.0 Subtotal $14,000.0 +25% Contingencies $3,500.0 Total $17,500.0 is C 1/18/2006 PA 20 Appendix A • Opinion of Probable Cost Problem Area 22 - 5635 Harding Lane • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Re -erade Back Yard Areal Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $1,500.00 $1,500.0 2 Clearing and Grubbing 0.3 Ac $1,200.00 $360.0 3 Excavation 350 CY $14.00 $4,900.0 4 Restoration 1 LS $400.00 $400.0 Subtotal $7,160.0 +25% Contingencies $1,790.0 Total $8,950.0 Preliminary Opinion of Probable Cost - Option 2 (Construct New Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $1,200.00 $1,200.0 2 Storm Sewer (12" HDPE) 200 LF $24.00 $4,800.0 3 Catch Basins and Manholes 2 EA $2,000.00 $4,000.0 4 Restoration 1 LS $250.00 $250.0 Subtotal $10,250.0 +25% Contingencies $2,563.0 Total $12,813.0 Preliminary Opinion of Probable Cost - Option 3 (Construct Previously Proposed Improvements) Adjusting for inflation, it is anticiapted that the construction costs associated with this option will be $87,000. 1/18/2006 PA 22 Appendix A Opinion of Probable Cost Problem Area 24 - 23980 Yellowstone Trail A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $15,000.00 $15,000.0 2 Remove Bituminous Pavement 640 SY $5.00 $3,200.0 3 Storm Sewer (12" RCP) 970 LF $35.00 $33,950.0 4 Catch Basins and Manholes 9 EA $1,250.00 $11,250.0 5 Base Course Aggregate 110 CY $8.00 $880.0 6 Bituminous Pavement 500 TN $150.00 $75,000.0 7 Curb & Gutter 1940 LF $12.00 $23,280.0 8 Turf Establishement 1620 Sy $2.00 $3,240.0 Subtotal $165,800.0 +25% Contingencies $41,450.0 Total $207,250.0 • 1118/2006 PA 24 Appendix A • Opinion of Probable Cost Problem Area 26 - 5815 Eureka Road A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. • Preliminary Ouinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $300.00 $300.0 2 Excavation 15 CY $10.00 $150.0 3 Furnish and Place Field Stone Riprap 5 CY $80.00 $400.0 4 Type IV Geotextile Fabric 40 SY $2.00 $80.0 Subtotal $930.0 +25% Contingencies $233.0 Total $1,163.0 • 1/18/2006 PA 26 Appendix A Opinion of Probable Cost Problem Area 28 - 5600 Wedgewood Drive A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration a2 also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Re -grade Ditch to Provide Positive Outlet to West) Item No. Description Quantity Unit Unit Cost Total I Mobilization 1 LS $1,500.00 $1,500.0 2 Excavation 500 CY $10.00 $5,000.0 3 Restoration I LS $300.00 $300.0 4 Wetland Mitigation 0.3 AC $25,000.00 $7,500. Subtotal $14,300. +25 °/a Contingencies $3,575.0 Total $17,875.0 Preliminary Opinion of Probable Cost - Option 2 (Construct New Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $15,000.00 $15,000.0 2 Remove Bituminous Pavement 1600 SY $5.00 $8,000.0 3 Storm Sewer (12" RCP) 850 LF $35.00 $29,750.0 4 Catch Basins and Manholes 4 EA $1,250.00 $5,000. 5 Base Course Aggregate 275 CY $8.00 $2,200. 6 Bituminous Pavement 360 TN $150.00 $54,000. 7 Turf Establishement 1800 SY $2.00 $3,600.0 8 Wetland Mitigation 0.3 AC $25,000.00 $7,500. Subtotal $125,050. +25 %Contingencie $31,261 Total $156,313.0 • • • 1/1812006 PA 28 Appendix A is Opinion of Probable Cost Problem Area 29 - 26395 Peach Circle A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. • Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $4,500.00 $4,500.0 2 Excavation 1700 CY $10.00 $17,000.0 3 Restoration 1 LS $300.00 $300.0 Subtotall $21,800.0 +25% Contingenciesi $5,450.0 Totall $27,250.0 • 1118/2006 PA 29 Appendix A Opinion of Probable Cost Problem Area 31 - 24735 Glen Road A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Storm Sewer (15" HDPE - directional bore) 400 LF $100.00 $40,000.0 3 Storm Sewer (27" RCP) 200 LF $85.00 $17,000. 4 Catch Basins and Manholes 4 EA $750.00 $3,000.0 5 Cleanout Existing Pipe at Railroad 1 LS $500.00 $500.0 6 Restoration 1 LS $2,500.00 $2,500.0 Subtotal $65,500.0 +25 % Contingencies $16,375.0 Totall $81,875.0 :7 • 1/18/2006 PA 31 Appendix A is Opinion of Probable Cost Problem Area 34 - 5900 Afton Rd A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. • Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $300.00 $300.0 2 Excavation 70 CY $15.00 $1,050.0 3 Restoration 1 LS $300.00 $300.0 Subtotal $1,650.0 +25% Contingencies $413.0 Total $2,063.0 • 1/18/2006 PA 34 Appendix A Opinion of Probable Cost Problem Area 38 - 23075 State Hwy 7 A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Construct New Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $1,200.00 $1,200.0 2 Remove Bituminous Pavement 81 SY $5.00 $405.0 3 Storm Sewer (15" RCP) 200 LF $40.00 $8,000.0 4 Catch Basins and Manholes 2 EA $1,250.00 $2,500.0 5 Base Course Aggregate 15 CY $8.00 $120.0 6 Bituminous Pavement 15 TN $150.00 $2,250.0 8 Turf Establishement 25 SY $2.00 $50.0 Subtotal $14,525.0 +25% Contingencies $3,631.0 Total $18,156.0 Preliminary ODinion of Probable Cost - Option 2 (Construct Manhole Over Existing Storm Sewer) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $500.00 $500.0 2 Manhole 1 EA $1,250.00 $1,250.0 3 Restoration 1 LS $250.00 $250.0 Subtotall $2,000.0 +25% Contingencies $500.0 Totall $2,500.0 LJ • 1/18/2006 PA 38 • Appendix A Opinion of Probable Cost Problem Area 42 - 5970 Strawberry Lane • • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. IDescription Quantity Unit Unit Cost Total i Mobilization 1 LS $1,200.00 $1,200.0 2 Remove Bituminous Pavement 40 SY $5.00 $200.0 3 Storm Sewer (15" CMP) 30 LF $25.00 $750.0 4 Salvage and Reinstall Base Course Aggregate 8 CY $12.00 $96.0 5 Bituminous Pavement 5 TN $150.00 $750.0 6 Turf Establishment 15 SY $2.00 $30.0 7 Excavate to Provide Positive Drainage 25 CY $12.00 $300.0 Subtotal $3,326.0 +25% Contingencies $832.0 Total $4,158.0 1/18/2006 PA 42 Appendix A Opinion of Probable Cost Problem Area 43 - Amesbury Townhomes A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option 1 (Increase Storage and Construct New Storm Sewer Upstream) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $800.00 $800.0 2 Storm Sewer (12" HDPE) 210 LF $24.00 $5,040.0 3 Catch Basins and Manholes 3 EA $750.00 $2,250.0 4 Common Borrow 100 CY $8.00 $800.0 5 Restoration 1 LS $500.00 $500.0 Subtotal $9,390.0 +25% Contingencies $2,348.0 Total $11,738.0 Preliminary Opinion of Probable Cost - Option 2 (Construct New Storm Sewer Downstream of Knightsbridge) Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $800.00 $800.0 2 Storm Sewer (48" RCP) 370 LF $110.00 $40,700.0 3 Catch Basins and Manholes 2 EA $1,250.00 $2,500.0 4 Restoration I LS $500.00 $500.0 Subtotal $44,500.0 +25% Contingencies $11,125. Total $55,625.0 • • 1/18/2006 PA 43 • Appendix A Opinion of Probable Cost Problem Area 44 - 6045 Burlwood Ct • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization I LS $5,000.00 $5,000.0 2 Remove Bituminous Pavement 60 SY $5.00 $300.0 3 Storm Sewer (12" RCP) 40 LF $35.00 $1,400.0 5 Salvage and Reinstall Base Course Aggregate 8 CY $12.00 $96.0 6 Bituminous Pavement 13 TN $150.00 $1,950.0 7 Curb & Gutter 20 LF $12.00 $240.0 8 Turf Establishement 30 SY $2.00 $60.0 Subtotall $9,046.0 +25% Contingenciesl $2,262.0 Totall $11,308.0 1/18/2006 PA 44 Appendix A Opinion of Probable Cost Problem Area 47 - 6060 Strawberry Ln A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Oninion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $300.00 $300.0 2 Excavation 15 CY $15.00 $225.0 3 Restoration 1 LS $300.00 $300. Subtotal $825.0 +25% Contingencies $206.0 Totall $1,031.0 • • 1/18/2006 PA 47 • Appendix A Opinion of Probable Cost Problem Area 49 - 20480 Radisson Road • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500. 2 Remove Bituminous Pavement 200 SY $5.00 $1,000.0 3 Salvage and Reinstall Base Course Aggregate 35 CY $12.00 $420.0 4 Excavation 20 CY $15.00 $300.0 5 Bituminous Pavement 45 TN $150.00 $6,750.0 5 Curb & Gutter 200 LF $12.00 $2,400.0 Subtotal $13,370.0 +25% Contingencies $3,343.0 Total $16,713.0 1/18/2006 PA 49 Appendix A Opinion of Probable Cost Problem Area 50 - 6120 Riviera Lane A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Remove Bituminous Pavement 200 SY $5.00 $1,000.0 3 Salvage and Reinstall Base Course Aggregate 35 CY $12.00 $420.0 4 Excavation 20 CY $15.00 $300.0 5 Bituminous Pavement 45 TN $150.00 $6,750.0 Subtotal $10,970.0 +25% Contingencies $2,743.0 Total $13,713.0 • • 1118/2006 I PA 50 • Appendix A Opinion of Probable Cost Problem Area 51 - 26505 Maple Ave • • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total I Mobilization 1 LS $3,500.00 $3,500.0 2 Remove Bituminous Pavement 80 SY $5.00 $400.0 3 Storm Sewer (12" RCP) 600 LF $35.00 $21,000.0 4 Storm Sewer (15" RCP) 600 LF $40.00 $24,000.0 5 Storm Sewer (18" RCP) 1900 LF $50.00 $95,000.0 6 Catch Basins and Manholes 10 EA $1,250.00 $12,500.0 7 Salvage and Reinstall Base Course Aggregate 20 CY $12.00 $240.0 8 Bituminous Pavement 20 TN $150.00 $3,000.0 9 Turf Establishment 6200 Sy $2.00 $12,400.0 Subtotal $172,040.0 +25% Contingencies $43,010.0 Total $215,050.0 1/18/2006 PA 51 • APPENDIX B 0 • Analysis of Drainage Problem Areas within the City of Shorewood January 23, 2006 Shorewood, Minnesota WSB Project No. 1459 -04 Appendix B List of Recommended Maintenance Items • Number Address Maintenance Activity Required Additional Comments 7 5925 Grant St Remove obstructions from pipe entrances Home owner should be responsible fors stem on their prope 12 21165 Mtka Blvd Remove obstructions from pipe entrances 13 4770 Lakeway Terrace Replace beehive casting with higher capacity rate One -time activit 15 800 Water Street Remove silt from FES at TH 7/41 intersection 17 123350 Academy Remove silt from CB grate/replace with beehive grate 24 23980 Yellowstone Tr Continue monitoring water level Additional pumping may be necessa 33 26275 Smithtown Rd Remove obstructions from pipe entrances 34 5900 Afton Rd a. Repair sink hole adjacent to CB west of Afton Rd. One -time activi b. Re-grade turf areas adjacent to Afton Rd Provide positive drainage from road surface; one -time activit c. Repair sink holes at culverts east of Afton Rd One -time activi 46 15480 Teal Circle Remove obstructions from ditch 49 120480 Radisson Road Place temporary bituminous curb at end of driveway 1118/2006 K: \01459 -04 \Final Drainage Problem Report\Appendix B • SUPPLEMENTAL REPORT ANALYSIS OF DRAINAGE PROBLEM AREAS WITHIN THE CITY OF SHOREWOOD PREPARED FOR THE CITY OF SHOREWOOD, MINNESOTA • January 22, 2007 Prepared By: WSB & Associates, Inc. 701 Xenia Avenue South, Suite 300 Minneapolis, MN 55416 (763) 541 -4800 (763) 541 -1700 (Fax) 40 TABLE OF CONTENTS • CERTIFICATION I . INTRODUCTION .................................................... ..............................1 II. DISCUSSION OF PROBLEM AREAS .......................... ..............................3 III. SUMMARY AND RECOMMENDATIONS ................... .............................xx LIST OF APPENDICIES APPENDIX A - Opinion Of Probable Cost For Selected Problem Areas (Category 3 and 5) • • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood Shorewood, Minnesota January 22, 2007 TOC CERTIFICATION I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly licensed professional engineer under the laws of the State of Minnesota. Steven Gurney, P.E. Date: January 22, 2007 Reg. No. 40497 is Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood Shorewood, Minnesota January 22, 2007 I. INTRODUCTION • On January 23, 2006, a report entitled "Analysis of Drainage Problem Areas within the City of Shorewood" was approved by the Shorewood City Council. Since that time, other property owners have contacted the City requesting that their property be added to the list. The history behind the original report is not reiterated here; however, the various categories previously established during the preparation of that report are outlined below: 1) PUBLIC SAFETY AND HEALTH Primary attention will be paid to those projects that impact the public health or safety. These projects would include ice problems on the road, erosion that is causing a hazardous structural problem (i.e. undermining a road), or storm water that is causing a significant health problem (such as flooding the sanitary system). 2) SUBSTANTIAL FINANCIAL IMPACT TO THE CITY This category will include those projects that, while not endangering the public health, will still have a negative impact on the residents as a whole. Projects in this category include minor infrastructure replacement that cannot be funded cost effectively by other means. Other potential projects include erosion causing property damage and minor structure replacement. 3) PUBLIC NUISANCE • This category includes those projects that cannot be considered a substantial hazard, are not likely to cause a financial loss to the City, but are a public nuisance. These projects include standing water in the roadway, unwanted flooding in public parks, and minor erosion projects. 4) PRIVATE NUISANCE WITH LIMITED CITY RESPONSIBILITY This category includes projects that are a nuisance to a single residence or small group of residences that the City Council deems that the City has some responsibility to help correct. These projects include those instances where a large drainage area is causing a problem to a small area or where a substantial portion of the runoff is generated within the City's Right -of -Way. In order for the City to participate, the homeowner(s) must be willing to provide a right - of -entry to City crews and provide Drainage and Utility Easement over improvements without cost. 5) PRIVATE NUISANCE WITH NO CIT''Y RESPONSIBILTY This category includes projects that are a nuisance to a single residence or small group of residences that the City Council deems that the City has no responsibility to help correct. These projects include those instances where a limited drainage area, consisting of • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 1 WSB Project No. 1459 -04 • private property, is causing a problem to a small area. The nuisance problem will involve little or no runoff that is generated from City Right -of -Way. 6) NO FURTHER ACTION REQUIRED This category includes projects that are under way, or have been addressed through various means, such as individual homeowners correcting the problem himself or herself or City crews fixing the problem. The problem areas are all evaluated and a category assigned so that the City Council can begin to prioritize the problem areas. With the exception of three areas, the new problem areas are areas that either the City has no responsibility for or no further action is required. Therefore, Tables 1 -6, created as part of the original report, are not updated here. The new problem areas can simply be added to the bottom of the lists as there is no prioritization needed for these new areas. • 0 Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 21, 2007 Shorewood, Minnesota Page 2 WSB Project No. 1459 -04 II. DISCUSSION OF PROBLEM AREAS • Since the original report was approved by the City Council, the City received additional drainage complaints. Since that time, we have investigated each of the various areas to visit with concerned residents, gather additional information, take pictures, and where possible, observe the problems. The results of this preliminary investigation are presented in the following pages. Each problem area has a brief description of the complaint expressed by the property owner followed by a summary of the hydrologic characteristics of the subwatershed tributary to the site. Next, possible alternatives that may be considered to address the problems at the subject site are outlined. A preliminary cost estimate for each alternative is also provided. Following that is a recommendation by WSB as to how the City should proceed. Most of the areas are within private property and do not require much additional investigation by City Staff or their consultants. However, there are several areas that, because of their proximity to or the amount of public property involved in the tributary area, will require further review. Unless otherwise noted, the hydrologic information is based on a cursory review of the subwatershed tributary to the problem area. The Soil Conservation Service's TR -20 method was used to estimate flow rates from the subwatershed directly tributary to the problem area. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 3 WSB Project No. 1459 -04 • Problem Area Number 52 — 5985 Eureka Rd Description of Problem: The property owner contacted the City concerned about the amount of water flowing through their property. They indicated that he water was so high during the September 2005 storm that it overtopped Eureka Road. A review of the City's contour information indicates that this is property contains a drainage way that conveys runoff from areas east of the property. Typically, road culverts are designed to convey runoff from a storm event up to a 10 -year storm event. After that, the runoff is allowed to overtop the road unless doing so would threaten to flood an upstream property. The contours also show that the house is at least one foot higher than the low point in the road, so runoff will overtop the road before flooding the house. It appears that the culvert is functioning as designed. Hydrologic Information: • Tributary Area: 13.4 ac • Impervious Surface: 10% • Peak 10 -year Flow Rate: 26 cfs • Peak 100 -year Flow Rate: 48 cfs Possible Alternatives: • There is no alternative identified for this area as the system seems to be functioning properly, and there is no danger of the house being flooded by surface water runoff. Should the property owner decide to place fill in their yard, caution must be exercised that the grading does not block runoff from other properties. Any fill greater than 50 cubic yards will require a permit. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the system appears to be functioning as designed. is Supplemental Report Analysis of Drainage Problens Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 4 WSB Project No. 1459 -04 • Problem Area Number 53 — 6180 Cathcart Dr Description of Problem: The property owner contacted City Hall concerned about water being back up on her property. The property owner had placed fill on the property and placed silt fence along the edges, as required. Across the street, a small pond had been recently excavated. During the grading of this pond, the outlet of the culvert under the road had been partially obstructed with riprap. The riprap was re- positioned so the water would drain from the yard at 6180 Cathcart. In addition, the silt fence placed on the property was blocking a small amount of additional water. Sediment removal, consistent with usual maintenance of silt fence will address this condition. Hydrologic Information: • No hydrologic analysis completed since the problem has been addressed. Possible Alternatives: There is no alternative identified for this area as the system seems to be functioning properly, provided regular maintenance is performed on the remaining silt fence. Once turf is established, the silt fence can be removed. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the problem appears to have been addressed. Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 5 WSB Project No. 1459 -04 • Problem Area Number 54 — 4940 Suburban Dr Description of Problem: The property owner contacted City Hall complaining that runoff from the road had flooded her property. After further discussion, it was clarified that the only problem was actually just standing water on a small portion of the yard. The property owner indicated that they were in the process of constructing an in- ground swimming pool, and they were concerned about what could be done with runoff from their driveway area. The proposed plan will essentially maintain the existing flow patterns through his portion of the property; however, the runoff will be conveyed in a pipe rather than via an overland Swale. The change is acceptable, provided the concentrated runoff is allowed to dissipate at the edge of the property. Hydrologic Information: • Tributary Area: 0.88 ac • Impervious Surface: 32% • Peak 10 -year Flow Rate: 2.4 cfs • Peak 100 -year Flow Rate: 3.9 cfs Possible Alternatives: There is no alternative identified for this area as the system seems to be functioning properly, • provided existing runoff patterns are not drastically altered during construction of the in- ground pool, as required by the building permit. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since this will be addressed during the building permit process. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 6 WSB Project No. 1459 -04 Problem Area Number 55 — 5590 Timber Lane Description of Problem: The property owner contacted City Hall complaining that his yard was soggy and did not drain properly. The property owner indicated that he would like to place fill in the yard to eliminate some of the low areas. A review of the City's contour information indicates that a low point is present in the northeast comer of the property. The property owner indicated that he would like to place fill in the yard to eliminate the low spot. He also asked if the culvert in the southeast corner of his property could be cleaned out. This culvert is in the County right -of -way. During the summer, the ditch downstream of the culvert was jetted out, which should improve the performance of the culvert. Hydrologic Information: • Tributary Area: 0.88 ac • Impervious Surface: 32% • Peak 10 -year Flow Rate: 2.4 cfs • Peak 100 -year Flow Rate: 3.9 cfs Possible Alternatives: • There is no alternative identified for this area since there is no danger of the house being flooded by surface water runoff. Should the property owner decide to place fill in their yard, a permit would be require for fill greater than 50 cubic yards. The costs for this work will be $1,700 to $5,000 depending on the amount of fill used. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5) since the poor drainage through the low area is an existing condition not caused by any action of the City. is Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota I Page 7 WSB Project No. 1459 -04 • Problem Area Number 56 — 24645 Glen Road Description of Problem: The property owner contacted City Hall complaining about standing water on her property. The property owner indicated that she thought the recent wetland restoration work done on the Gideon Glen site created this condition. A review of the City's contour information indicates that the low area on her property is several feet higher than the Gideon Glen wetland. The house itself is approximately 6 inches above the overflow elevation of the low area. While this is less than the minimum standard of 1 foot that would be applied for new construction, the small drainage area tributary to this low point will not likely result in flooding of the house. The Minnehaha Creek Watershed District also reviewed the site and concurred that the problem was not related to their work in the wetland. The standing water was most likely caused by snow melting before the ground was thawed, which would have allowed it to infiltrate into the ground. Hydrologic Information: • Tributary Area: 0.60 ac • Impervious Surface: 40% • Peak 10 -year Flow Rate: 1.8 cfs • Peak 100 -year Flow Rate: 2.9 cfs • Possible Alternatives: There is no alternative identified for this area since there is no danger of the house being flooded by surface water runoff. Should the property owner decide to pump the standing water from her yard, it is anticipated that the costs for this work will be $100 to $500 depending on the duration of pumping. Recommendation: It is recommended that this problem area be categorized as a "Private Nuisance with No City Responsibility" area (Category 5) since the standing water in low area is caused by an existing condition which was not created by any action of the City. Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 8 WSB Project No. 1459-04 Problem Area Number 57— 6080 Strawberry Lane Description of Problem: The property owner contacted City Hall concerned about standing water in her back yard. It appears this was created when the builder of the new house behind her pumped out the into the common backyard low area. This new house is part of the same development. A review of the grading plan for the development indicates that a drainage swale was to have been excavated that will convey runoff from the common back yards to the ditch adjacent to the HCRRA trial. The developer has been made aware of this, and the swale will be constructed prior to releasing the letter of credit associated with the grading work. Hydrologic Information: • No hydrologic analysis completed since the problem will be addressed through the building permit process. Possible Alternatives: There is no alternative identified for this area as the problem will be addressed as part of the building permit process and / or approval of the development. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the problem will be addressed by other avenues. Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 9 WSB Project No. 1459-04 • • • • Problem Area Number 58 — 26370 Peach Circle Description of Problem: The property owner contacted City Hall concerned about standing water in the street. The source of the water is the sump pump discharge from 26395 Peach Circle (see Problem Area 29) that is directed to Peach Circle. A catch basin is located in the cul -de -sac, near the east lot line of this property. The storm sewer then conveys runoff to a stormwater treatment pond at the back of the property. The only apparent outlet for this pond is the overland overflow. Based on a review of the City's 1 -foot contours, it appears the overflow is approximately 1.5 feet lower than the elevation of the lowest building opening on adjacent structures. Due to the relatively flat grade of the road and areas of settlement on the road surface, there is standing water present immediately after rainfall events, or when the sump pump is discharging. The property owner also expressed dissatisfaction with the pond on his property, which appears to have been built as part of this subdivision. Hydrologic Information: • Tributary Area: 1.74 ac • Impervious Surface: 36% • Peak 10 -year Flow Rate: 4.9 cfs • Peak 100 -year Flow Rate: 8.0 cfs • Possible Alternatives: The following alternatives are available to reduce the nuisance flooding in this area: 1. Re -grade the Peach Circle road surface and install curb & gutter along with additional storm sewer. It is anticipated that the construction costs associated with this work will be approximately $71,000. Substantial cost savings would be realized if this work was to be completed as a part of the reconstruction of the Peach Circle road surface. 2. An interim fix that could be constructed to reduce the standing water on Peach Circle would be to install a draintile along the south edge of the road, and connect to the catch basin in the cul -de -sac. A bituminous patch could then be placed on the street to restore the crown. Recommendation: It is recommended that this problem area be categorized as a "Public Nuisance" area (Category 3.) The project is not cost - effective unless it is done as part of an overall reconstruction of Peach Circle. Therefore, it is recommended that the project not be undertaken until the City reconstructs the road surface at Peach Circle. Prior to beginning work, the easements over the storm sewer and pond should be verified and, if not in place, secured before proceeding. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22,1007 Shorewood, Minnesota Page 10 WSB Project No. 1459 -04 Problem Area Number 59 — 5875 Afton Road Description of Problem: The property owner contacted the City concerned about water flowing through his yard. The runoff appears to be contained in a designed drainage swale that conveys runoff through the property. Hydrologic Information: • Tributary Area: 34.4 ac • Impervious Surface: 35% • Peak 10 -year Flow Rate: 67.9 cfs* • Peak 100 -year Flow Rate: 113.3 cfs* * Flow rate on runoff from entire tributary area, neglecting upstream ponding. Possible Alternatives: There is no alternative identified for this problem area as the system appears to be functioning as designed. All runoff is being contained in the drainage and utility easements. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the runoff conveyed through this property is contained within the existing drainage and utility easement. Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewooi4 Minnesota Page 11 WSB Project No. 1459 -04 • • • • Problem Area Number 60 — 5935 Howard's Point Road Description of Problem: The property owner contacted the City concerned about standing water on his property. A review of the City's one -foot contours confirms that there is a depression on the south half of this lot. The adjacent low point, at the intersection of Howard's Point Road and Smithtown Road, is approximately two feet below the apparent low building opening of the house on this property. Hydrologic Information: • Tributary Area: 1.5 ac • Impervious Surface: 17% • Peak 10 -year Flow Rate: 2.7 cfs • Peak 100 -year Flow Rate: 4.6 cfs Possible Alternatives: There is no alternative identified for this area since there is no danger of the house being flooded by surface water runoff. Should the property owner decide to place fill in their yard, a permit would be require for fill greater than 50 cubic yards. The costs for this work will be $1,700 to $5,000 depending on the amount of fill used. • Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since there is adequate freeboard above the overflow section that will convey runoff away from the property before surface waters would flood the house. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 12, 2007 Shorewood, Minnesota Page 12 WSB Project No. 1459-04 Problem Area Number 61— 5830 Echo Road Description of Problem: The property owner contacted the City concerned that the culvert located on the west edge of the property was not function properly. A review of the site indicates that the culvert is functioning as intended. There is a spot on the road that will hold water. It appears that over time the edges of the lawns are higher than the edge of the road. This traps water on the road surface this can be fixed by minor grading along the edge of the road. Hydrologic Information: • Tributary Area: 1.5 ac • Impervious Surface: 17% • Peak 10 -year Flow Rate: 2.7 cfs • Peak 100 -year Flow Rate: 4.6 cfs Possible Alternatives: The standing water in this area can be fixed by minor grading along the edge of the road. However, it is likely that, over time, the edges of the road would again block the runoff from leaving the road surface. In order to address this, a storm sewer and catch basin s could be installed to convey runoff directly to the nearby ditch. The cost for this work is estimated to be approximately $30,000. Substantial cost savings could be realized if the storm sewer • improvements are incorporated into the site plan for a new City Hall when that project is initiated. Recommendation: It is recommended that this problem area be categorized as a "Public Nuisance" area (Category 3.) The installation of a storm sewer system in this area is not cost - effective unless it is done as part of the overall reconstruction of the area for a new City Hall building. However, it is recommended that limited grading be done by the City's Public Works crews to allow runoff to leave the road surface. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22,1007 Shorewood, Minnesota Page 13 WSB Project No. 1459-04 • Problem Area Number 62 — 5520 Grant Lorenz Road Description of Problem: The property owner contacted the City concerned that the open channel that conveys runoff through his property has become choked with sediment. He also contends that the alleged sediment deposition has blocked the flow of runoff through his property, thereby creating wetland conditions. A comparison of the City's one -foot contours from 1966 and 1999 do not show an increase in elevation within this property, or the nearby surrounding properties. This would most likely indicate that sediment deposition, if any, was very limited. In fact, the majority of this parcel appears to be slightly lower based on the 1999 survey compared to the 1966 survey. This is most likely due to the presence of peaty soils that tend to compress naturally over time. Hydrologic Information: • Tributary Area: 53 ac (direct), 305 ac (direct and indirect)* • Impervious Surface: 19% • Peak 10 -year Flow Rate: 75 cfs • Peak 100 -year Flow Rate: 150 cfs * Tributary area is approximated from larger tributary area (subwatershed WC 4) as identified in CSMP. Possible Alternatives: There is no alternative identified for this problem area as the system appears to be functioning as originally intended. The property owner could raise the low area by importing fill. This would require a conditional use permit, as well as permit from the MCWD. The property owner is responsible for preparing a wetland delineation report to determine the exact limits of wetlands on the property. Recommendation: It is recommended that this problem area be categorized as a "No Further Action Required" area (Category 6) since the system appears to be functioning as originally intended. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 14 WSB Project No. 1459 -04 Problem Area Number 63 — 23610 Gillette Curve • Description of Problem: The property owner contacted City Hall concerned about standing water in the street. This is caused by the small bituminous hump placed at the end of the property owner's driveway. If this were not in place, the runoff would be conveyed down the driveway and into the garage that is approximately one foot lower that the edge of the street. The area of standing water is relatively small (approximately two feet by four feet.) Hydrologic Information: • Tributary Area: 1.09 ac • Impervious Surface: 32% • Peak 10 -year Flow Rate: 2.1 cfs • Peak 100 -year Flow Rate: 3.5 cfs Possible Alternatives: To reduce the nuisance flooding in this area, it is recommended that Gillette Curve be re- graded and curb & gutter installed along with additional storm sewer. It is anticipated that the construction costs associated with this work will be approximately $32,000 to $150,000. Substantial cost savings would be realized if this work was to be completed as a part of the reconstruction of the Gillette Curve road surface. • Recommendation: It is recommended that this problem area be categorized as a "Public Nuisance" area (Category 3.) The project is not cost - effective unless it is done as part of an overall reconstruction of Gillette Curve. Therefore, it is recommended that the project not be undertaken until the City reconstructs the road surface at Gillette Curve. Prior to beginning work, the easements over the storm sewer and pond should be verified and, if not in place, secured before proceeding. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 15 WSB Project No. 1459 -04 0 III. SUMMARY AND RECOMMENDATIONS Generally, the City's drainage issues outlined in this Supplemental Report can be classified as nuisance flooding, with a few exceptions. Of the 12 problem areas, nine are identified as "Private Nuisance with No City Responsibility" (Category 5) or "No Further Action Required" (category 6.) The three exceptions are areas classified as "Public Nuisance "(Category 3.) In all three cases, the nuisance is a small area of standing water on the road, smaller than 500 square feet in size. Based on this, it is recommended that no major construction be undertaken at these areas until the roads are reconstructed. In the meantime, it may be possible to make temporary fixes that will address the standing water until it can be permanently addressed as part of a larger project. In order to address the three problem areas as separate projects, the estimated costs range is between $107,000 and $251,000. The narratives in the report mention that, due to economy of scale, significant savings may be realized by doing these projects as part of a larger road reconstruction project. Funding: Currently, the City has in place a stormwater fee. As design alternatives are considered, utilization of the stormwater fees, in conjunction with special assessments for benefiting areas, will need to be considered. • Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22,1007 Shorewood, Minnesota Page 16 WSB Project No. 1459 -04 APPENDIX A 0 Supplemental Report Analysis of Drainage Problem Areas within the City of Shorewood January 22, 2007 Shorewood, Minnesota Page 17 WSB Project No. 1459 -04 • Appendix A Opinion of Probable Cost Problem Area 55 - 5590 Timber Lane 0 • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization I LS $200.00 $200. 2 Imported Fill 275 CY $12.00 $3,300.0 3 Restoration 1 LS $500.00 $500.0 Subtotal $4,000.0 +25% Contingencies $1,000.0 Total $5,000.0 1/18/2007 PA 55 Appendix A Opinion of Probable Cost Problem Area 56 - 24645 Glen Road A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Pumping (including pump rental) 4 HR $100.00 $400.0 Subtotal $400.0 +25 %Contin encies $100.0 Total $500.0 • 1/18/2007 i PA 56 • Appendix A Opinion of Probable Cost Problem Area 58 - 26370 Peach Court • • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.00 $2,500.0 2 Remove Bituminous Pavement 900 SY $5.00 $4,500.0 3 Salvage and Reinstall Base Course Aggregate 160 CY $12.00 $1,920.0 4 Excavation 120 CY $15.00 $1,800.0 5 Catch Basins 2 EA $1,200.00 $2,400.0 6 Storm Sewer (15" RCP) 350 LF $40.00 $14,000.0 7 Bituminous Pavement 200 TN $150.00 $30,000.0 Subtotal $57,120.0 +25 %Contingencies $14,280.0 Total $71,400.0 1/18/2007 PA 58 Appendix A Opinion of Probable Cost Problem Area 55 - 5590 Timber Lane A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Oainion of Probable Cost Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $200.00 $200.0 2 Imported Fill 275 CY $12.00 $3,300. 3 Restoration 1 LS $500.00 $500.0 Subtotal $4,000.0 +25% Contin encie $1,000.0 Totall $5,000.0 • • 1/18/2007 PA 60 • Appendix A Opinion of Probable Cost Problem Area 61 - 5830 Echo Road • • A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost Item No. Description Quantity Unit Unit Cost Total I Mobilization 1 LS $1,200.00 $1,200.0 2 Remove Bituminous Pavement 300 SY $5.00 $1,500.0 3 Salvage and Reinstall Base Course Aggregate 80 CY $12.00 $960.0 4 Excavation 50 CY $15.00 $750. 5 Catch Basins 2 EA $1,200.00 $2,400. 6 Storm Sewer (15" RCP) 45 LF $40.00 $1,800.0 7 Bituminous Pavement 100 TN $150.00 $15,000.0 Subtotal $23,610.0 +25% Contingencies $5,903.0 Total $29,513.0 1/18/2007 PA 61 Appendix A Opinion of Probable Cost Problem Area 63 - 23610 Gillette Curve A preliminary opinion of probable cost is given below. Costs are for the construction of improvements only and do not include easements and / or land acquisition costs. It is anticipated that the benefited property owners will donate easements. Costs for engineering and administration are also not included. Costs may vary significantly based on final scope of project. Actual costs will be determined when survey and feasibility reports are completed. Preliminary Opinion of Probable Cost - Option I (Storm Sewer Connection to Minnetonka Drivel Item No. Description Quantity Unit Unit Cost Total 1 Mobilization 1 LS $2,500.0 $2,500.0 2 Remove Bituminous Pavement 1700 SY $5.0 $8,500.0 3 Base Course Aggregate 550 CY $14.0 $7,700.0 4 lExcavation 120 CY $15.0 $1,800.0 5 Catch Basins 2 EA $1,200.0 $2,400.0 6 Storm Sewer (l5" RCP) 700 LF $40.0 $28,000.0 7 Bituminous Pavement 550 TN $125.0 $68,750.0 Subto $119,650A +25 %Contingend $29,9130 Total $149,5630 Preliminary Opinion of Probable Cost- Option 2 (limited Storm Sewer at Cul-de -sac) Item No. Description Quantity Unit Unit Cost Total I Mobilization 1 LS $1,200.0 $1,200.0 2 Remove Bituminous Pavement 250 SY $5.0 $1,250.0 3 Base Course Aggregate 100 CY $14.0 $1,400.0 4 lExcavation 50 CY $15.0 $750.0 5 Catch Basins 2 EA $1,200.0 $2,400.0 6 Storm Sewer (15" RCP) 75 LF $40.0 $3,000.0 7 Bituminous Pavement 125 TN $125.0 $15,625.0 Subtota $25,6250 +25 %Contingend $6,406.0 Totail $32,03111 is • i s 1/1812007 PA 63