Conflict between Flood and Drought Preparedness in the Colorado River Basin

Abstract

The Colorado river dominates water resource development in the seven states of the southwestern US. It also is one of the most carefully managed river systems in the world. The basin has been arbitrarily divided by the Colorado River Compact into the Upper Colorado Basin and the Lower Colorado Basin for purposes of interstate administration. A wide range of climate occurs throughout the basin because of differences in altitude, latitude, and topographic features. Considered here are current and projected scenarios of management use. Examined are the combined legal, institutional, hydrologic and water demand constraints, and how they are managed under circumstances of increasingly competitive uses. As a case study, the current analysis examines the 1983 spring and summer flooding in the Lower Basin and whether the US Bureau of Reclamation adequately managed the heavy spring runoff from the Upper Basin. This analysis stresses that the reasons for the flooding go beyond the climatic events of the year and the Bureau of Reclamation’s response to them. Rather, the flooding was the result of the convergence of three factors: (1) the 17-year period of filling Lake Powell behind Glen Canyon Dam ended and the system of water storage reservoirs on the river basin considered full; (2) during the filling period, physical encroachment into the Lower Basin flood plain accelerated; (3) the streamflow forecast procedures were not suitable for the extreme climate variability of the Colorado river basin, as exhibited in 1983.