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<br /> <br /> STAFF REPORT <br /> <br /> <br /> <br />TO: Mayor Keis and Members of City Council <br /> <br />FROM: Bill Dircks, Public Works Director <br /> DATE: June 4, 2019 <br /> RE: Twin Lake Emergency Meeting Information <br />As of Monday morning, the level of Twin Lake was 875.92 feet. With the continued flow of water <br />into the lake from the overflowing West Vadnais Lake as well as rain on Tuesday evening, the lake <br />level will likely be higher than 876 feet on Wednesday. That means it will officially be higher than the <br />low house on the lake at 154 Twin Lake Blvd. As you know, the ultimate overflow to the MnDOT <br />system is at 877 feet – one foot higher than the lowest house. <br />Due to these factors, the Ramsey Washington Metro Watershed District Board of Commissioners will <br />be discussing emergency pumping of Twin Lake at its meeting Wednesday, June 5, at 6:30 p.m. They <br />will consider all of the modeling information, as well as threats to downstream properties and will <br />either recommend beginning a pumping operation or letting the lake reach its ultimate overflow of 877 <br />feet. <br />In anticipation of the possibility that pumping may be started, the City and Watershed District have <br />met with MnDOT and received a permit to pump into its system, and also applied for and received an <br />appropriations permit from the MN DNR to pump the lake down. <br />The primary goal of pumping the lake down is to get the lake to a safe level below the lowest house on <br />the lake at 154 Twin Lake Blvd. Due to the water flowing in from West Vadnais the pump will have <br />to be set up to pump more out than is coming in to the lake. That is anticipated to be anywhere from <br />2,500 to 10,000 gallons per minute. It is unknown at this time how long it may take to get the lake to <br />a safe level but it is important to at least get it stabilized so that it doesn’t bounce any higher and <br />potentially affect the next lowest homes on the lake. Due to the concerns downstream, the pumps would <br />be turned off in anticipation of rain events to ensure the extra water does not cause other homes to <br />flood. <br />Staff and the Watershed District walked the site with a representative of Northern Dewatering and <br />Frank Frattalone on Tuesday morning and determined the best place to set up the pump and where to <br />run the discharge hose. Based on those specifications and some rough calculations by Northern <br />Dewatering, the anticipated setup and first month costs will be in the neighborhood of $25,000. <br />Monthly costs after that are dependent on how often Northern Dewatering maintenance staff needs to <br />check on the pump and how much fuel is required. A gravel road will also need to be constructed <br />through a portion of Mr. Frattalone’s field to ensure that trucks and the fuel truck can get to the pump. <br />Mr. Frattalone has offered to build that road and will be providing a cost for the work. Staff has asked <br />the City Engineer for an estimate so the estimate can be compared.