The TRWA water quality sampling results for July 14th are available. Go to our website homepage and click on the Water Quality Monitoring tab at the top of the website homepage and either the picture of the sample bottles or the link under the Documents section to see the latest results as well as the results from past years.
The July river flow as measured at the Bridgewater USGS gauge, which covers about half the watershed and measures the flow coming into the area we sampled, was 87 cubic feet per second (cfs) when we sampled on 7/14/26. This flow is approximately 1/5 of what the river flow was at the beginning of May (410 cfs). The last rain before we sampled was July 8th, when river flow reached 401 cfs, but then quickly fell over the next six days until we sampled. Climate change has given our watershed and New England a drought summer weather pattern consisting of short-duration intense storms with intervals of warm, dry weather. As we see from the USGS river flow record, our rainfall during drought runs off quickly to the ocean rather than replenishing our river base flow and public and private wells.
The results showed higher nitrogen levels than our target below the Brockton and Bridgewater wastewater treatment plants (WWTPs) due to the low river flow. By Taunton, however, instream nitrate levels met our target for Mount Hope Bay. Phosphorus levels were elevated, likely due to low streamflow in the Assonet River and for the Town River below the Bridgewater WWTP, which is scheduled to begin removing phosphorus starting 5/1/2027. With only one exception, the state bacteria water quality criteria were exceeded at every location we sampled, most likely due to low river flow.
The drought continues. We continue to see the saw tooth pattern in river flow typical of a watershed in drought. TRWA’s sampling is important to tell us how the river and tributaries are responding to the climate change-induced drought we are seeing each summer and provide important insight concerning what must be done to minimize the impact of drought on our watershed’s water quality and drinking water supplies.