Agenda - Planning Commission - 05/04/2017 - Special

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Pearson Farm Residential Development EAW Draft — March XX, 2017 Shorelands The shoreland overlay district of Lake Itasca (DNR public water 2-110P) extends over approximately 193,605 square feet (4.4 acres) in the northwestern part of the site (Figure 8). Lake Itasca has a Natural Environment shoreland classification and is located 600 to 1,000 feet north of the site. Lake Itasca is a shallow lake that covers about 130 acres. It has an Ordinary High Water (OHW) level of 871.4 feet (NGVD 29 Datum). Development in shorelands is regulated under the City of Ramsey Shoreland Management Overlay District Ordinance (Section 117-221 to 117-229) and Minnesota Rules Part 6120. The Minnesota state legislature has delegated authority for regulation of development in shorelands of public waters to local government units as a means to preserve and enhance the quality of surface waters, conserve the economic and natural environmental values of shorelands, and provide for the wise use of waters and related land resources. Shoreland is defined as land located within 1,000 feet from the OHW of a lake. However, the definition in the City of Ramsey City code and at MN Rules 6120.2500, Subp. 15 states that the "limits of shorelands may be reduced whenever the waters involved are bounded by topographic divides which extend landward from the waters for lesser distances and when approved by the [DNR] commissioner." The shoreland on the project area is eligible to be reduced because Alpine Drive NW functions as a drainage divide. The project area will not drain north or affect Lake Itasca. The project area drains east through a culvert under Puma Street NW. Although a culvert exists under Alpine Drive NW at the north end of the site, the control elevation in the culvert is 870.4 feet. This control elevation is higher than the elevation of nearby delineated wetland boundaries and 0.7 feet higher than the wetland's 1% frequency flood elevation, which is 869.7 feet. Given these elevations, the proposed development is not predicted to affect Lake Itasca. Floodnlains Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) Map Number 27003CO280E, dated December 16, 2015, shows an unnumbered Zone A 1% frequency floodplain of Lake Itasca located north of site and north of Alpine Drive NW (Figure 8). Flood Zone A includes special flood hazard areas subject to inundation by the 1% annual chance of flood. The Lake Itasca floodplain is outside the project area. The floodplain of the Mississippi River is located about 1,350 feet southwest of the project area, and at an elevation about 15 feet lower than the project area. An analysis of Lake Itasca water levels under existing and future land uses was conducted for a previous development. That analysis showed that Lake Itasca does not outlet during 100-year snowmelt and rainfall events, but modeled water levels came close to reaching the outlet on the south side of the lake, so the City of Ramsey proposed to install an outlet for the lake. The City assumed that any outlet elevation would be above the OHW of 871.4 feet and the approximate 100-year flood elevation of 871.0 feet. 7