Hydrology, Geomorphology and Vegetation - Feedback Loops & Implications for Restoration. A case study of Dry Creek, CA

4:30 - 5:30



Dry Creek, a major tributary to the Russian River in Sonoma County, is home to native threatened and endangered fish, and has remained a system of interest for ongoing regional endangered species recovery planning. Dry Creek’s current hydrology is regulated by Warm Springs Dam (WSD) and unregulated tributaries which enter Dry Creek below WSD. The geomorphic nature of lower Dry Creek is a result of the interaction between local geology, watershed characteristics, hydrology, and vegetation; the legacy of channel evolution and response to land management changes; and the ongoing influence of flow management. A primary control on geomorphology has been the feedback between regulated hydrology and vegetation, where elevated summer baseflow and reduced winter high flows have resulted in vigorous growth of riparian vegetation. Prolific vegetation establishment in the overbank regions have sequestered alluvial surfaces and sediment sources, resulting in narrowing and channelization of the main channel. Elevated baseflows, in combination with curtailed flood hydrology, supports the dense riparian communities currently present, which in turn, have reduced habitat forming processes that create habitats such as alcoves, backwaters, and side channels.

Room Name
Ballroom C