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Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations

River Research and Applications

By:
and
DOI: 10.1002/rra.1293

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Abstract

Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologic infrastructure and management affect streamflow characteristics of rivers in the Central Valley, California and discuss those characteristics in the context of habitat requirements of native and alien fishes. We evaluated the effects of water management by comparing observed discharges with estimated discharges assuming no water management ("full natural runoff"). Rivers in the Sacramento River drainage were characterized by reduced winter–spring discharges and augmented discharges in other months. Rivers in the San Joaquin River drainage were characterized by reduced discharges in all months but particularly in winter and spring. Two largely unaltered streams had hydrographs similar to those based on full natural runoff of the regulated rivers. The reduced discharges in the San Joaquin River drainage streams are favourable for spawning of many alien species, which is consistent with observed patterns of fish distribution and abundance in the Central Valley. However, other factors, such as water temperature, are also important to the relative success of native and alien resident fishes. As water management changes in response to climate change and societal demands, interdisciplinary programs of research and monitoring will be essential for anticipating effects on fishes and to avoid unanticipated ecological outcomes.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations
Series title:
River Research and Applications
DOI:
10.1002/rra.1293
Volume
26
Issue:
6
Year Published:
2010
Language:
English
Publisher:
John Wiley & Sons, Ltd.
Publisher location:
Hoboken, NJ
Contributing office(s):
California Water Science Center
Description:
15 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
River Research and Applications
First page:
751
Last page:
765
Country:
United States
State:
California
Other Geospatial:
Central Valley