Twin Cities Metropolitan Area Regional Groundwater Flow Model Version 2.00 : Technical Report in Support of the Metropolitan Area Master Water Supply Plan

The 2005 Minnesota Legislature directed the Metropolitan Council to "carry out planning activities addressing the water supply needs of the metropolitan area" (Minnesota Statutes, Section 473.1565). Specifically, the Council is charged with developing a base of technical information for water supply planning decisions and to prepare a metropolitan area master water supply plan. The goal of these efforts is to guide sustainable water use in the Twin Cities metropolitan area. In order to address the legislature's directive, the Council prepared a Metropolitan Area Master Water Supply Plan composed of a robust water availability analysis, the community profiles that ensuing from it, and the datasets that underlie it. These core pieces together constitute the Metropolitan Area Master Water Supply Plan. Developing a modern regional groundwater flow model was determined to be the best approach to assess water supply availability under projected water demand conditions, and the resulting regional model serves as the foundation of the Metropolitan Area Master Water Supply Plan. Regional numerical groundwater flow modeling has been a component of Twin Cities metropolitan area water resource planning for decades. The United States Geological Survey developed a regional groundwater flow model in the late 1980's with the purpose of testing possible effects of projected groundwater withdrawals from the Prairie du Chien-Jordan and drift aquifers in the Twin Cities metropolitan area The Minnesota Pollution Control Agency's Twin Cities Metropolitan Groundwater Model Version 1.00 (Metro Model), developed in the 1990's, was very successful in compiling hydrogeologic data into a single data repository, including the development of the base elevations of key bedrock aquifers and aquitard units and a cross-correlated calibration data set of groundwater level measurements. The Metro Model also laid out a conceptual model of the region's groundwater flow system that is still in use today. In addition, several smaller-scale models have been developed over the last decade. They have been used for a wide variety of projects, including wellhead/source water protection, siting of new municipal wells, evaluation well interference effects, and addressing the impacts on trout streams and calcareous fens.