Projects by Discipline / Water Resources Planning and Management

Severe Sustained Drought Study

The economy of the American Southwest has been built by establishing a reliable water supply in a largely arid land. The principal supply of water comes from the Colorado River. To overcome seasonal and multi-year fluctuations in water availability, federal and state governments have built a massive system of reservoirs and delivery systems on the Colorado River and its tributaries. The laws of the seven states in the Colorado River basin that define the use of water from the river have evolved over more than a century to protect past water development investments. Since 1922, interstate compacts, court decrees and federal regulations have developed to define the entitlements of the states.

In California, a system of comparable scope has been developed to move water from the more humid northern parts of the state to the large population centers of metropolitan Los Angeles. This system operates in its own institutional environment.
In Arizona, a smaller system of reservoirs and canals delivers water from the Salt and Verde rivers to the metropolitan area of Phoenix. This water supply is supplemented by substantial amounts of groundwater from large aquifers underlying the region. Recognizing the importance of these aquifers, Arizona has instituted a strict groundwater management statute.
The Colorado River Aqueduct and the Central Arizona Project deliver water from the Colorado River to Los Angeles and Phoenix respectively, linking them to the Colorado River basin.

This system, at its present level of development, has never been called upon to face a major drought and there is substantial concern about the ability of the system to meet one. Thus far, the droughts of the twentieth century have not matched the duration or severity of droughts in the previous four centuries, as they can be reconstructed from the record of tree rings.
The Severe Sustained Drought project, sponsored by the U.S. Geological Survey has as its objective an assessment of the ability of water laws, institutions and management infrastructure in the extended Colorado River basin to cope with a severe and sustained drought; an analysis of the qualitative and quantitative impacts of drought on ecological, economic, social and political sectors of the basin and suggestions of potential methods of enhancing the resiliency of social and natural systems.

Hydrosphere was retained by the Utah Water Research Laboratory to make computer simulation model studies of the Colorado River system and the Salt River system to assess the ability of water laws, private and public institutions and water management infrastructure in the extended Colorado River basin to cope with a severe and sustained drought. Hydrosphere also performed an analysis of the qualitative and quantitative impacts of drought on ecological, economic, social and political sectors of the basin and provided suggestions of potential methods of enhancing the resiliency of social and natural systems.

A compilation of the research conducted under this project was published in the Water Resources Bulletin in October 1995 and reproduced with permission here.