SMC study to explore options for improving biological health of modified channels

The Southern California Stormwater Monitoring Coalition (SMC) has approved a three-year, SCCWRP-led study to be launched next year that will evaluate multiple potential management options for improving the biological health of streams that have been modified through channel hardening.

The study, greenlit by the SMC in September, will examine the environmental factors that cause modified channels to generally score poorly on the California Stream Condition Index (CSCI) and Algal Stream Condition Index (ASCI) bioassessment scoring tools.

Researchers will examine if and how bioassessment scores might be improved if managers invest in a range of actions, including improving water quality, altering flow management practices, changing channel maintenance regimes and restoring the channels to a less modified state.

Modified channels, which make up an estimated 40% of all stream-miles in coastal Southern California, tend to receive poorer bioassessment scores than other types of streams.