2015-02-11 CC Packet - Laserfiche WebLink

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Draft North & East Metro Groundwater Management Area Plan 2-8 Water Dependent Natural Resources The GWMA boundary was influenced by natural resources in the area, particularly the surface water features that are sensitive to changes in groundwater levels.The boundary includes surface water and ecological features connected to the hydrogeology. Managing groundwater appropriations will have a direct impact on the health of these natural resources.The following features within the North & East Metro GWMA will benefit from inclusion: Six designated trout streams of eastern Washington County, along with seven non-designated streams that support a coldwater community including trout • Wetland complexes across the entire area Lakes that may be sensitive to changing aquifer levels Sixteen types of groundwater-associated native plant communities f State-listed rare plant and animal species associated with groundwater ® Numerous additional plant and animal species that inhabit streams, lakes, and wetlands that are associated with groundwater Washington County Trout Streams The DNR has the authority to designate trout streams. Designation provides increased protection from alterations and appropriations. In addition,the Minnesota Pollution Control Agency (MPCA) maintains higher water quality standards for coldwater streams to protect these sensitive systems. DNR has designated six trout streams in Washington County: Falls Creek, Gilbertson Creek,Old Mill Stream, Willow Brook, Brown's Creek, and Valley Creek (Figure 2-6).They range in size and character based on geology and land use. Tributaries to listed trout streams within the same sections are also designated as trout streams (Minn. Rules, part 6264, subp. 4), although the tributaries may not support trout or have perennial flow. Falls Creek, Gilbertson Creek, Old Mill Stream, and Willow Brook are all small streams that support self- sustaining brook trout populations, along with an occasional burbot, a fish species that also requires coldwater habitat.These streams have a mixture of public and private land in their watershed, and appear to be in good health based on the fish communities present.These streams are all spring-fed from bedrock aquifers along the St. Croix River Valley. Valley Creek in Afton is also spring-fed from bedrock aquifers. In the headwaters,there are predominantly brook trout and slimy sculpin (a small coldwater fish species),while in the middle and lower portions of the stream brown and rainbow trout predominate.American brook lamprey, non- parasitic lamprey species found in coldwater streams, is also present.This fish community is indicative of a healthy coldwater stream. Brown's Creek differs from the other Washington County trout streams because it originates in a large wetland complex.The upper reaches of Brown's Creek are unsuitable for trout because of the relatively warmer water temperature flowing from the wetland in summertime and the low dissolved oxygen P36