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Draft North & East Metro Groundwater Management Area Plan 2-1 2. Description of the Boundary and the GWMA A geographic area was defined within which to manage groundwater resources.The boundary for this GWMA was selected by using a combination of physical,governmental, and planning elements. Establishing a boundary allows us to identify and analyze factors that affect long term water use, and to identify specific actions that reduce the risk of unsustainable groundwater use. Elements considered in selecting the boundary of the GWMA included the following: • Hydrogeology • Water use • Water dependent natural resources • Water quality • Jurisdictions, governance and planning The boundary selected for the North & East Metro GWMA includes all of Washington and Ramsey counties, 10 cities in southeastern Anoka County, and the portion of Hennepin County east of the Mississippi River(Figure 2-1). Vertically, the boundary includes all parts of the groundwater system above the Eau Claire geologic formation.A more detailed description of the elements listed above is given in the documents: Draft Working Boundary N& E Metro GWMA and Updated Draft Working Boundary N& E Metro GWMA. Section 2 of this Plan provides summary information on the elements that were used to select the boundary for the North & East Metro GWMA. Hydrogeology Hydrogeology defines the natural conditions and boundaries of the groundwater system.The boundary includes the following: • The horizontal extent of the Prairie du Chien—Jordan aquifer between the hydrologic boundaries formed by the Mississippi and St. Croix rivers, except for localized outliers of these bedrock formations(Figure 2-2) • The hydrogeological transition area in southeastern Anoka County and Forest Lake in Washington County adjacent to the margin of the Prairie du Chien—Jordan aquifer • All aquifers above the Eau Claire Formation confining unit (Figure 2-3). The Mt. Simon aquifer (located below the Eau Claire Formation) is not included because it is hydrologically separated from the shallower aquifers within the area.Appropriations from the Mt. Simon are also restricted by statute in the seven county Twin Cities Metropolitan Area. Topographic watershed boundaries were reviewed. The watersheds are integral to groundwater health but generally do not match the hydrogeologic boundaries to the regional groundwater system. P29