The TRWA water quality sampling results for October 13th and all of the 2026 sampling season 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 2026 results as well as the results from past years.
The October 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 809 cubic feet per second (cfs) when we sampled on 10/13/26. A large rainstorm the day before we sampled caused river flow to go from 235 to 830 cfs overnight. When we sampled in October we saw a significant spike in stormwater related pollution from this storm. River flow today, November 1st is back down to 206 cfs.
Climate change has given our watershed and New England a drought summer weather pattern consisting of short-duration intense storms with relatively long 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 do a better job managing our stormwater.
The October monitoring results showed lower nitrogen levels than we saw during the low flows of this summer due to greater river flow dilution. Our nitrogen target for protection of Mount Hope Bay from algae blooms was met even right below the major wastewater treatment plants. Despite high river flow dilution phosphorus levels were elevated due to the phosphorus present in stormwater pollution. The big story for October is the very high bacteria levels measured at every sampling location which violated State water quality standards. These violations are from the pollution input from inadequately managed stormwater from impervious surfaces in the watershed.
At the end of September after the multi-day Nor’easter increased river flow to 2330 cfs the river flow fell back to 230 cfs in less than two weeks. The large storm before we sampled in October pushed river flow up to 820 cfs but within 2 weeks river flow is 206 cfs. Although river flow is somewhat improved from the 70 to 100 cfs drought flows of this summer our watershed has not recovered from drought. We can’t afford to waste the precious rainfall we recieve by letting it run off quickly to the ocean.
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. TRWA wants to thank the 40 dedicated volunteers who collect our samples.