In May 2001, the City began an extensive weekly water quality monitoring program of over 30 sites in Arroyo Burro, Laguna, Mission, and Sycamore creeks. Water samples are evaluated for the presence of indicator bacteria including total coliform and Enterococcus.
High levels of these bacteria are an indication that the water may contain other bacteria that are unhealthful for humans. Sampling sites were chosen in order to best evaluate water quality throughout City creeks, under a wide range of creek conditions, and to determine whether weekly sampling gives a demonstrably better picture of the variability in creek water quality.
Routine watershed assessment includes weekly and monthly sampling at key points in the watersheds and focuses on measuring indicator bacteria and habitat quality. The sampling program is designed to ask the following questions:
Project assessments include collecting and analyzing water quality data before and after projects are implemented. Data is collected upstream and downstream of the potential project sites, including data on indicator bacteria, habitat quality, and chemical pollutants. The sampling program is designed to answer these questions:
The goals of sampling at restoration and water quality improvement project sites are to attain at least one year of comprehensive baseline water quality data for creeks at restoration sites prior to project construction, to identify problem pollutants, and to track the effectiveness of the projects in reducing problem pollutants.
Project monitoring is also intended to determine the effect a particular restoration or water quality improvement project has on the quality of water for aquatic organisms including fish, invertebrates, amphibians, and plants.
The goal of sampling during storm events is to determine which pollutants are a problem throughout each watershed. The City tries to sample two storms, including the “first flush” and one of the larger storms of the year. The sampling strategy is designed to ask:
One of the main challenges to improving water quality is that the sources of bacterial pollution are often not known. Although high levels of indicator bacteria suggest that human waste may be present, there are many other sources of indicator bacteria, including those that are native to soils.
The Creeks Division participates in scientific research with Dr. Patricia Holden at UCSB that uses DNA-based techniques to try and determine if high indicator bacteria levels are coming from sources of human waste or animal waste. The goals of bacteria monitoring are to track changes in bacteria levels at key points in the watershed, at known hot spots, and where we plan to construct projects; determine the effectiveness of reducing bacteria at specific restoration and water quality project sites; and, to measure overall success of water quality improvement programs.