Ventura River Study (Santa Barbara and Ventura Counties)


The Ventura River was once home to of one the largest southern steelhead runs on the south coast, and is considered one of the four major steelhead-bearing watersheds in Southern California. The Ventura River is also one of five priority stream systems selected as part of the California Water Action Plan effort. The Ventura River watershed may experience long periods of dry conditions with little to no measurable precipitation, resulting in mainstem reaches becoming seasonally and even annually intermittent. In addition, moderate to extremely high episodic precipitation patterns and flow events may also occur in the winter months. This unpredictability in the timing, magnitude, frequency and duration of river flows limits the hydrologic connectivity of the riverine habitat for southern steelhead migrating to and from upstream spawning and rearing habitats.

To address the California Water Action Plan, the Department conducted several studies in the Ventura River watershed.

  • Two-dimensional hydraulic habitat models were built to assess adult steelhead passage flows in the intermittent reach of the mainstem Ventura River.
  • One-dimensional modeling within San Antonio Creek was used to determine instream flow needs for steelhead adult spawning and juvenile rearing.
  • Watershed-wide flow criteria were evaluated using site-specific methods and modeling tools to support steelhead life stages, maintain natural flow patterns, and support the riverine ecosystem.

The Ventura River study components are complete. Technical reports, appendices, calibration reports, and supporting materials are available below.


Ventura River Watershed Map - click to enlarge in new window
Click to enlarge