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HomeMy WebLinkAbout10B - Storm Sewer Repair MEETING DATE: AGENDA #: PREPARED BY:' PRESENTER: AGENDA ITEM: DISCUSSION: ISSUES: FINANCIAL IMPACT: 4646 Dakota Street SE Prior Lake. MN 55372 CITY COUNCIL AGENDA REPORT August 16, 2010 10B Steve Albrecht, Director of Public Works Steve Albrecht Consider Approval of a Resolution Authorizing the Emergency Repair of the Carriage Hills Storm Sewer System Outlet Introduction The purpose of this agenda item is to seek City Council approval to make emergency repairs to the Carriage Hills storm sewer outlet. Historv In the mid 1990's an outlet pipe for the Carriage Hills Development was installed on the Vierling Property to manage stormwater runoff. Last week's heavy rain resulted in erosion issues and eventual failure of that portion of the system. Current Circumstances On Friday, August 13, City staff inspected numerous storm water facilities after an estimated 3.8-inch rainfall event the previous night. The Carriage Hills outlet end section and two sections of storm sewer failed and slid down the embankment during the storm event. Additionally, it appears that a section of storm sewer 25 to 30 feet up stream also was damaged causing a sink hole. The attached pictures show the failed section and damage. In its current condition there is severe erosion to the existing wetland to the north. Additionally, without repair it is anticipated more damage will occur. The estimated cost of the repair is $20,000 to $30,000 depending on the extent of subsurface damage which is currently unknown. Conclusion Staff recommends the City Council authorize staff to make immediate repairs to the storm sewer before additional infrastructure and environmental damage occur. Failure to repair the damage will result in additional impacts to the City's storm sewer, private property and the wetland area to the north. The required funding for the repairs is available in the Water Quality Fund which is utilized for storm water system outlet repairs. Staff recommends that the 2010 Water Quality Fund budget be amended to reflect the additional expenses utilizing fund balance reserves as the funding source. R:\Council\2010 Agenda Reports\08 16 1O\Carriage Hills Storm Sewer.doc ALTERNATIVES: The alternatives are as follows: 1. Approve a resolution authorizing the repair of the Carriage Hills storm sewer outlet. 2. Table this agenda item for a specific reason. 3. Deny this agenda item for a specific reason and provide staff with direction. RECOMMENDED Alternative #1. MOTION: Reviewed by: Frank Boyles, City Manager R:\Council\2010 Agenda Reportsl08 16 1O\Carriage Hills Storm Sewer.doc 2 4646 Dakota Street SE Prior Lake. MN 55372 RESOLUTION 1 a-xxx A RESOLUTION AUTHORIZING REPAIR OF THE CARRIAGE HILLS STORM SEWER OUTLET Motion By: Second By: WHEREAS, The City owns and maintains a storm sewer system which includes the Carriage Hills storm sewer outlet to the Vierling Property; and WHEREAS, On August 13, 2010 after heavy rains, the outlet failed and slid down a slope causing severe erosion to the wetland located to the north; and WHEREAS, In order to mitigate the existing damage, and prevent additional damage to City infrastructure, private property and wetlands the City should repair the damage immediately; and WHEREAS, The estimated repair cost is $20,000 to $30,000. NOW THEREFORE, BE IT HEREBY RESOLVED BY THE CITY COUNCIL OF PRIOR LAKE, MINNESOTA as follows: 1. The recitals set forth above are incorporated herein. 2. The City Manager is authorized to approve expenditures for repairs not to exceed $30,000 for the storm sewer outlet. 3. Funds will be drawn from the Water Quality Fund Account # 602-49420-412. 4. The 2010 Water Quality Fund Budget will be amended to reflect the additional expense utilizing fund balance reserves as the funding source. PASSED AND ADOPTED THIS 16th DAY OF AUGUST, 2010. Myser Myser Erickson Erickson Hedbera Hedbera Keeney Keeney Millar Millar YES NO Frank Boyles; City Manager G:\AGENDA REPORTS AND RESOLUTIONS\2010\ 816 Equipment Purchase Resolution 8 16 10