Continuous, Real-Time Water-Quality Monitoring of the Los Angeles River

Science Center Objects

As part of the Urban Waters Federal Partnership (UWFP) program, this project will bring enhanced water-quality monitoring to a stretch of the Los Angeles River slated for revitalization. The UWFP reconnects urban communities—particularly those that are overburdened or economically distressed—with their waterways by improving coordination among federal agencies.

The Los Angeles River

The Los Angeles River flows from its headwaters in the Angeles National forest to the Pacific Ocean in Long Beach. Fifty-one miles long, the river covers 870 square miles of watershed and winds through 14 cities.

The river has many historic purposes. In one section, a concrete runoff ditch helps control flooding. The natural river is a source of recreation for the 4.4 million people living in the surrounding area.

Revitalization is planned for an 11-mile mile stretch of the Los Angeles River that runs from Griffith Park to downtown Los Angeles. Critical riparian and freshwater marsh habitat will be restored, as will more natural hydrologic processes. 

water quality monitoring equipment attached to a cement wall and partially submerged in water

Water quality monitoring sensor housing installed in the Los Angeles River, Los Angeles County, California. (Credit: Greg Mendez, USGS. Public domain.)

USGS Water-Quality Monitoring

To support these efforts, the USGS will provide high-quality, real-time, continuous water-quality data within this reach of the Los Angeles River. Data are expected to provide information for enhanced recreational use, inform local organizations and municipal entities interested in current water-quality and flow conditions, contribute to future assessments of factors affecting surface-water quality in this heavily urbanized area, and support science-based management practices to protect public land and water. 

Focusing on a reach of the river with a streamflow gage, the data from this study could indicate conditions when recreational activity is not suitable because of poor water-quality or high flow, provide a correlation point for discrete sampling locations in the watershed, and create a baseline for future hydrologic and ecosystem investigations.

Study Approach

The planned approach of this study will occur in three steps;

  1. evaluate potential sites along the Los Angeles River where continuous water-quality monitoring equipment could be installed; 
  2. collect continuous water-quality data with YSI sonde, installed near active gaging station 11092450, to collect specific conductance, pH, temperature, dissolved oxygen, turbidity, nitrate, fluorescence of dissolved organic matter, and chlorophyll; 
  3. quality-assure equipment and data and make available for viewing on the National Water Information System web interface.