Water Management

Ecological Applications, 13(1), 2003, pp. 206–224 2003 by the Ecological Society of America

ECOLOGICALLY SUSTAINABLE WATER MANAGEMENT: MANAGING RIVER FLOWS FOR ECOLOGICAL INTEGRITY

BRIAN D. RICHTER,1,5 RUTH MATHEWS,2 DAVID L. HARRISON,3

2

AND

ROBERT WIGINGTON4

1The Nature Conservancy, 490 Westfield Road, Charlottesville, Virginia 22901 USA The Nature Conservancy, 410 North 4th Street, Mt. Vernon, Washington 98273 USA 3Moses, Wittemyer, Harrison, and Woodruff, P.O. Box 1440, Boulder, Colorado 80306-1440 USA 4The Nature Conservancy, 2060 Broadway, Suite 230, Boulder, Colorado 80302 USA

Abstract. Human demands on the world’s available freshwater supplies continue to grow as the global population increases. In the endeavor to manage water to meet human needs, the needs of freshwater species and ecosystems have largely been neglected, and the ecological consequences have been tragic. Healthy freshwater ecosystems provide a wealth of goods and services for society, but our appropriation of freshwater flows must be better managed if we hope to sustain these benefits and freshwater biodiversity. We offer a framework for developing an ecologically sustainable water management program, in which human needs for water are met by storing and diverting water in a manner that can sustain or restore the ecological integrity of affected river ecosystems. Our six-step process includes: (1) developing initial numerical estimates of key aspects of river flow necessary to sustain native species and natural ecosystem functions; (2) accounting for human uses of water, both current and future, through development of a computerized hydrologic simulation model that facilitates examination of human-induced alterations to river flow regimes; (3) assessing incompatibilities between human and ecosystem needs with particular attention to their spatial and temporal character; (4) collaboratively searching for solutions to resolve incompatibilities; (5) conducting water management...