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potential improvement in more detail. This case will focus on section one of the report - 148th Lane <br />The site is east of Nowthen Boulevard (CSAH 5), southeast of Ramsey Elementary School. There is a low area <br />across three (3) lots south of 148th Lane, that was created as a stormwater pond for the area and wetland mitigation <br />for the development. There is a storm sewer inlet to this area along the west edge, which drains the subdivision to <br />the north. There is also an outlet from this area on the east end that connects to a pipe that runs easterly and parallel <br />to 148th Lane. The invert of this outlet pipe is approximately 2.5 feet above the low point in the basin. The outlet <br />pipe also connects to a structure in the boulevard of 148th Lane that takes storm water runoff from the roadway and <br />directs it easterly as described above. The inverts on both these pipes are at approximately the same elevation, and <br />therefore water may be entering this basin that is not intended to flow there from the stormwater system. It was also <br />observed that the basin has several undulations in the ground surface that do not allow the water to evenly spread <br />out across the entire drainage and utility easement; basically there appears to be three separate, somewhat <br />isolated basins. <br />Hakanson Anderson explored several options for installing another outlet and determined that each option would <br />not significantly affect the high water elevation in the basin, and would justify the costs associated with performing <br />them. Additional easements would need to be acquired, and disruption of neighboring properties would occur. <br />Staff is currently researching check valves that could be placed in the outlet pipe at the manhole to block drainage <br />from the street and only allow water to exit the basin through this structure, thereby eliminating additional flow to <br />the area. <br />Funding Source: <br />The funding source for these improvements is the storm water utility fund. It is estimated that regrading the basin <br />and installing a backflow valve on the outlet pipe would cost approximately $7,500 to $12,500. <br />Staff Recommendation: <br />Staff recommends regrading the backyards of the three properties to better distribute water in the basin, and <br />re-establish the original pond contours. It is further recommended to install a backflow valve on the outlet pipe to <br />direct storm water runoff from 148th Lane to the intended downstream receiving body. <br />Committee Action: <br />Motion to recommend to the City Council that staff seek quotes to regrade the backyards of the three properties to <br />better distribute water in the basin and re-establish the original pond contours, and to install a backflow valve on the <br />outlet pipe to direct storm water runoff from 148th Lane to the intended downstream receiving body. <br />Project Location Map <br />Section 1 of Hakanson Anderson Report <br />Inbox <br />Tim Himmer <br />Len Linton (Originator) <br />Tim Himmer <br />Len Linton (Originator) <br />Tim Himmer <br />Brian Olson <br />Kurt Ulrich <br />Form Started By: Len Linton <br />Attachments <br />Form Review <br />Reviewed By <br />Len Linton <br />Len Linton <br />Len Linton <br />Len Linton <br />Tim Himmer <br />MaryJo Warner <br />Kurt Ulrich <br />Final Approval Date: 05/11/2012 <br />Date <br />05/11/2012 08:35 AM <br />05/11/2012 09:51 AM <br />05/11/2012 11:03 AM <br />05/11/2012 11:08 AM <br />05/11/2012 11:25 AM <br />05/11/2012 11:29 AM <br />05/11/2012 11:54 AM <br />Started On: 05/09/2012 02:41 PM <br />