Since the late 1980s, TRWD has been collecting water quality data from each reservoir, the major tributaries to each reservoir and some wastewater plants near the reservoir. Samples are typically taken quarterly, and the data is used to monitor the health of the water on a short-term and long-term scale. The reservoirs were built for water supply, and for that purpose the water quality is in great shape. This chart
shows the parameters that are monitored. Read the most recent water quality executive summary.