MONITORING AND MANAGEMENT OF NONRENEWABLE GROUND WATER RESOUCES –

Management of nonrenewable ground water resources presents unique challenges for water users. Nonrenewable ground water resources include aquifers in which the rate of ground water extraction exceeds the rate of recharge. Depletion of nonrenewable ground water resources typically manifests itself in declining water levels. Deeper pumping and static water levels may result in lower well yields, greater pumping costs, more wells needed to produce historic pumping rates and water quality changes. The economic life of the system may be finite. Future aquifer conditions and well yields are difficult to predict due to the changes in aquifer characteristics resulting from changes in aquifer storage coefficient, saturated thickness or available water level drawdown in a well. Monitoring of changes in aquifer conditions, including: pumping and static water levels, well yields, total water use and water quality can aid those relying on the resource in meeting peak demands, planning for new infrastructure, evaluating when renewable water supplies need to be brought online and developing conjunctive use water supplies. The nonrenewable Denver Basin aquifers have been relied upon since the early 1900's to support municipal, industrial and irrigation water demands from the Rocky Mountain Front Range between Colorado Springs and Greeley across the plains to Limon. In the Denver Basin, well pumping exceeds recharge and ground water is being mined. Many Denver Basin ground water users are beginning to confront challenges associated with declining water levels, including decreased well yields and greater pumping costs. The region is arid and the surface water basins overlying the aquifers are over appropriated; available renewable surface water supplies are limited and expensive. Best practices for monitoring Denver Basin wells has allowed water users to plan for well yield declines and develop sustainable water supply strategies.