Simulation of mine drainage for preliminary development of oil shale and associated minerals, Piceance basin, northwestern Colorado

The Piceance basin of northwestern Colorado contains large resources of oil shale, nahcolite, and dawsonite. Development of these minerals will require drainage of water from mines. A six-layer hydrologic model of the basin was prepared to simulate mine drainage for mineral development. Streams and major tributaries were simulated as head-dependent nodes. Stream nodes were gaining or losing, but the rate of loss was constrained by the leakance of the streambed and the stream stage. Springs also were simulated as head-dependent nodes that stop flowing if the aquifer head declines below the spring orifice. (USGS)