Research Areas > Regional Monitoring > Watershed Regional Monitoring > Regional Watershed Assessments > Establishing Reference Conditions in Southern California

Project: Establishing Reference Conditions in Southern California Streams

Background and Objectives

Conducting bioassessment of streams and rivers also requires the characterization of reference-quality streams, which can be used to establish benchmarks of baseline condition expectations at impaired streams. The biological communities at reference sites can be used to develop benchmarks (biocriteria) for regulatory and management purposes. Furthermore, long-term monitoring at reference sites can aid detection of impacts from large-scale, long-term phenomena, such as climate change, wildfires, and aerial deposition of nutrients and metals. SCCWRP maintains a network of high quality reference sites in southern California for long-range assessment criteria.

This program is a component of a larger statewide effort to monitor reference streams throughout California. However, because large portions of southern California have been extensively modified from their former natural state, different approaches to establishing biocriteria are needed for this region. SCCWRP will help to implement these monitoring approaches.

Status

This project was initiated in 2009 with anticipated completion in 2012.

Methods

A pool of sites meeting stringent criteria for reference condition will be identified using pre-existing data sets and by screening for known stressors, such as water chemistry and physical habitat alteration. Under-represented regions and classes of streams (such as low-gradient streams in southern California) will be added to the pool through multiple approaches, such as relaxing criteria to identify true reference condition. In addition, SCCWRP will assemble historical (i.e., pre-impact) data, and use data on biological community along environmental gradients to model reference conditions at southern California sites if no sites currently in reference condition are available.

Partners

California Department of Fish and Game
State Water Resources Control Board
Los Angeles Regional Water Quality Control Board
Santa Ana Regional Water Quality Control Board
San Diego Regional Water Quality Control Board
Surface Water Ambient Monitoring Program
US EPA