Study exploring how to dramatically streamline stream causal assessments

SCCWRP and its partners have begun test-driving a novel approach to assessing stream health that has the potential to shave a year or more off the time required to determine cause of ecological degradation at a stream site.

Instead of conducting a stream condition assessment first, and then following up with a causal assessment later, researchers are seeking to collect data for both assessments during the same field sampling event. Year 1 field sampling for the three-year study was completed in June in San Bernardino County’s Big Bear watershed.

The causal assessment approach being tested during the study is a rapid, screening-level evaluation, where a standard list of possible stressors is either eliminated from consideration or identified as a possible cause of impairment based on a standard set of evidence types.

During Year 1 field sampling, researchers collected causal assessment data at the same time as they gathered condition assessment data. Condition assessments are conducted via stream health scoring tools such as the California Stream Condition Index, co-developed by SCCWRP.

Condition assessments typically take about six months, while causal assessments – which are typically not started until the condition assessment is completed – often take a year.