Welcome to the California Regional Water Quality Control Board - Santa Ana Region Welcome to the California Environmental Protection Agency
Governor's Webpage
My Water Quality
Performance Report
Planning Sections

Causal Assessment Project for San Diego Creek

Biologically-based assessments (bioassessment) of stream health are becoming the foremost approach to evaluate the condition of California's perennial stream ecosystems. If in this process the biology of a stream is found to be degraded in some fashion, the cause(s) of the problem will need to be identified so as to inform corrective measures or other management actions. Causal assessment is the sequence of steps taken to diagnose the stressor(s) leading to that degraded biology. The US EPA has developed the only fully realized causal assessment framework/tool for use in stream environments- CADDIS (Causal Assessment Diagnosis and Decision Information System).

The first goal of this project is to build local capacity and expertise in causal assessment through implementation of the CADDIS framework in the San Diego Creek Watershed. In partnership with Regional Board staff, the Southern California Coastal Water Research Project (SCCWRP) will help facilitate a causal assessment of San Diego Creek (Orange County/Irvine) using the US EPA CADDIS framework and the SCCWRP Draft California Causal Assessment Guidance Document.

The second goal of this project will be to develop technical improvements to the CADDIS framework to produce more diagnostic and streamlined assessments in California. Specifically, we will test the diagnostic capabilities of regional, environmentally similar comparator sites selected from California's state-wide bioassessment database versus the traditional in-stream comparator sites.

Phase 1 tasks include setting up the assessment, identifying candidate causes, aggregating all of the data, and analyzing the causes. Phase 2 work will be to score the analyses, evaluate the candidate causes as likely, unlikely, or indeterminate, and complete comparison of multi-reach vs. single site causal assessments.

Interactive Workshop #4 - February 11, 2016 at SCCWRP : Draft Lines of Evidence (LOE)

Interactive Workshop #3 - July 28, 2015 at SCCWRP

Interactive Workshop #2 - April 21, 2015 at SCCWRP

Interactive Workshop #1 - February 3, 2015 at SCCWRP


Workshop #1 - December 17, 2014 at SCCWRP





For more information, please contact Doug Shibberu at (951) 782-7959 or Heather Boyd at (951) 320-2006