The TRWA water quality sampling results for August 11th 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 August river flow as measured at the Bridgewater USGS gauge, which covers about half the watershed and measures the flow coming into the area we sample, was 122 cubic feet per second (cfs) when we sampled on 8/11/26. The last rain before we sampled was a brief but very intense rainstorm on August 4th which caused localized street flooding and river flow to quickly spike to 776 cfs. But as happens during New England’s climate change induced weather pattern stream flow quickly fell over the next week.
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. For this reason TRWA supports better stormwater management through updated state and local standards for new development called the watershed protection standard and EPA residual designation of existing unregulated commercial stormwater sources to bring them under stormwater management. As we see on the national news coverage of flash flooding and disappearing water supplies we need to better manage our stormwater.
The results showed higher nitrogen levels than our target below the Brockton and Bridgewater wastewater treatment plants (WWTPs). By Taunton, however, instream nitrate levels met our target for Mount Hope Bay. Phosphorus levels were elevated in many locations reflecting inadequate management of stormwater pollution from existing development. Every location sampled violated state water quality criteria for bacteria by a large amount reflecting the pollution input from inadequately managed stormwater from impervious surfaces in the watershed.
The drought continues, river flow on September 1st was only 70 cfs. We continue to see the up and down 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.