San Gabriel River Regional Monitoring Program

History of Program

Prior to implementation of the SGRRMP, water quality monitoring efforts focused on addressing potential impacts associated with point and non-point source loadings to the San Gabriel River with most of the monitoring concentrated in the Mainstem, downstream of discharges and at major tributary confluences. As a result, little was known about stream condition in the rest of the watershed, especially the upper watershed. In addition, managers knew little about human health issues related to swimming in streams throughout the watershed and the safety of consuming fish from local lakes and streams.
The monitoring program followed a phased, four year implementation plan with additional indicators added each year from 2005 through 2008. Monitoring began in 2005 and focused on the water quality conditions of the watershed as they related to Questions 1 and 2 by measuring aquatic chemistry, toxicity, and biological and physical habitat conditions at random and targeted sites.

In 2006 bacterial indicators (Question 4) and fish tissue bioaccumulation (Question 5) were added to address questions about water quality, swimming safety and potential risks to human health.

In 2007 the effort to characterize the San Gabriel River Estuary (Question 2) began with the collection of annual water quality, sediment chemistry, toxicity, and biological community samples. In addition, the effort to assess water quality compliance below major discharges using LACSD receiving water data was begun (Question 3).

Finally, in 2008 the final segment of the monitoring program was initiated when assessment of wetland habitat conditions commenced at four habitats of high quality using CRAM assessments (Question 2). Therefore, all elements of the program were successfully sampled in 2008 representing a four year implementation.


Adaptive Monitoring

The SGRRMP is an adaptive monitoring program so that modifications to the sampling design can be made as current monitoring data is assessed. For example:

  1. The original program design for stream condition (Question 1) had 10 samples being collected annually at randomly selected sites. Over eight years of sampling nearly 90 sites had been sampled and stream condition across the watershed was well understood. As a result the numbers of samples per year were reduced and resources were allocated to other parts of the sampling program.
  2. Sites selected for swimming safety (Question 4) included sites in the lower watershed at recreational lakes where it was later learned that extensive chlorination systems had been installed to protect the public from water born disease. As a result, the resources for these sites were moved to new sites in the upper watershed where public use was heavy.