Ownership of mine-tunnel discharge

Water discharging from numerous tunnels constructed during mining in the Wa satch Mountains near Salt Lake City, Utah, flows into nearby creeks, Disput es over ownership of water feeding the creeks have resulted in extensive li tigation. In the course of a legal dispute over ownership of outflow from t he Kentucky-Utah (K-U) Tunnel we evaluated the patterns and rates of ground water flow using an integrated study of the geology, chemistry, isotopes, and chlorofluorohydrocarbon (CFC) composition of the water. A sequence of s edimentary rocks with a range of hydraulic conductivity values has been fol ded, faulted, intruded by igneous rocks, and then eroded to create the roug h topography of the Wasatch Mountains. The similarity of composition among tunnel discharge, springs, and base flow in the creek indicates that the cr eek is fed by ground water circulating in local, shallow flow systems. Resu lts of numerical simulations of ground water flow indicate that the K-U Tun nel likely intercepts ground water that, in the absence of the tunnel, woul d ultimately flow in the subsurface to Big Cottonwood Creek. CFC and tritiu m contents of the water indicate flow weighted average ground water travel times range from four to 23 years and support our conclusion that water dis charging from the tunnel is moving within a shallow ground water flow syste m. Despite sparse data, the scientific understanding was deemed sufficient for the judge to rule that owners of the surface water also own the tunnel discharge because, in the absence of the tunnel, this water would supply th e stream.