Ground-Water Surface-Water Conflicts

Users of surface water and ground water from hydraulically connected sources (referred to as stream-aquifer systems herein) are on a collision course in many areas. The ground-water engineer or hydrologist has made considerable progress in the past 40 yr in understanding and mathematically simulating responses in stream-aquifer systems. But unfortunately, development and use of water from many stream-aquifer systems preceded the availability and use of such modeling techniques. Further, laws and other socioeconomic factors make implementation of conjunctive use plans extremely difficult. Many state water laws do not address the potential conflict between surface-water and ground-water users. Some states apply one water-rights doctrine to ground water, and a different one to surface water in stream-aquifer systems although the same water is involved in both. One state (Colorado) has passed legislation specifically addressing the problem of water rights in stream-aquifer systems. The 10 yr of experience with this legislation could be helpful to other state legislatures and water administrators.