The Mount Hope River

The Mount Hope River

Last month I wrote about the Still River and Bigelow Brook in the first of my series about smaller rivers within The Last Green Valley National Heritage Corridor.

The series is inspired by a group of water resources professionals, community leaders and other interested folks who are working to develop the Natchaug River Healthy Watershed Initiative. Their work will help communities and landowners understand specific issues of concern for the health of the watershed and establish benchmarks for working together to ensure the current and future cleanliness and vitality of the Natchaug River watershed. The group is called Naturally Natchaug, and you can find out more by going to their Facebook page at:

It was about five years ago when I first set foot in the Mount Hope River. Thankfully, I was wearing hip waders with thick rubber boots as I stepped into the stretch of river flowing past Ashford Town Hall.

I wasn’t there to fish. I was there to collect invertebrate bugs and receive training for Riffle Bioassessment with Jean Pillo, Coordinator for the TLGV Volunteer Water Quality Monitoring Program and Watershed Conservation Project Manager for the Eastern Connecticut Conservation District (ECCD). TLGV began its volunteer water quality monitoring program in 2006 and a close working relationship with ECCD was born. Our volunteers collect the data and ECCD and others use it to remediate problems. When I joined Jean five years ago, I wanted to see for myself the important, and fun, work our volunteers were doing. I was there to learn how to collect, identify and count the type of bugs that begin their life in water. We were looking for the species of macroinvertebrates that help define clean water. We recorded those we found and sent samples off to biologists at the Connecticut Department of Energy and Environmental Protection. Finding four of these species is a key indicator of good water quality.

The Mount Hope River is part of the Natchaug River watershed. It begins at the outlet of Morey Pond on the Union and Ashford border. From there it flows 15 miles through Ashford and Mansfield and enters Mansfield Hollow Lake on the southern end of the town. Mansfield Hollow Lake is also fed by the Natchaug River and Fenton River.

I knew Jean was the person to talk to when it comes to understanding the Mount Hope River – especially the river’s water quality conditions today. I knew I would learn something new and interesting about this waterway from Jean. I got more than I expected when she responded, “get ready for the big Mount Hope River brain dump!” Here is what she wrote:

“The Mount Hope River is listed as not meeting water quality standards for recreation due to periodic high levels of E. coli bacteria. In 2013, TLGV volunteers assisted the ECCD with a bacteria track-down survey of the watershed, which confirmed the non-compliance with Connecticut water quality standards and located some tributaries that were contributing to the impairment.”

ECCD recommended a series of actions based on the water quality data and the survey. The 30-page report is detailed and an excellent example of the quality work and reporting done by ECCD. It can be found at the following link:

ECCD was able to implement one recommendation from the report through a federal EPA grant allocated by CT DEEP. It worked with a local llama farmer to relocate a manure pile and install a covered manure storage shed to reduce runoff of water into the river that would have nutrients and pathogens from the llama manure.

Rarely is there one issue when a waterway is compromised, and ECCD has continued its work to restore the health of the Mount Hope River.

Jean said “as part of that track-down survey, we determined that Bassett Brook, a tributary of the Mount Hope River, was not meeting water quality standards as well. ECCD is currently addressing a probable source of that contamination by installing cement dumpster pads at an apartment complex. These pads will direct runoff (dumpster juice) from the dumpster stations to rain gardens where nature will filter out the pollutants. ECCD will also be installing storm drain filter inserts in two storm drains that currently drain directly into the brook.”

“In 2018 and 2019, TLGV volunteers were involved in temperature monitoring in the Mount Hope River watershed at the request of the CT DEEP Fisheries department. Six temperature gages were placed upstream and downstream of a well field to see if groundwater withdrawal so close to the river impacted water temperature downstream of the site.”

“The temperature loggers were programmed to record the temperature of the water every hour from June 1 to Aug. 31. CT DEEP has not yet published their interpretation of the data. As part of this effort, Grants Brook in Mansfield, a tributary of the Mount Hope River, was determined to meet cold water stream temperature criteria.”

“CT DEEP published a report on the physical, chemical and biological attributes of least disturbed watersheds in the state. They selected 30 small watersheds for this study, and three of them, Knowlton Brook, Gardner Brook and Bebbington Brook, are tributaries to the Mount Hope River.”

Like many of our waterways the information about the Mount Hope River is a mixture of good news and not so good news. Temperature logging and the Riffle Bioassessment data collection have revealed few sites with the important four or more macroinvertebrates criteria, with some sites varying from year to year.

The takeaway from all this information is that the Mount Hope River is an important part of the natural resources we rely on here in The Last Green Valley and we must be more aware of how our human activities impact it. Along with the Fenton and Natchaug Rivers, the Mount Hope flows into Mansfield Hollow Lake – the source of water for Willimantic Reservoir that provides drinking water for the Town of Windham.

These small streams are important to all of us and thanks to the joint efforts of staff from CT DEEP, ECCD and volunteers from TLGV, the monitoring and reporting on the water quality and health of these rivers will continue. When problems are discovered, we can collectively work to mitigate the source of contamination.

We live in a beautiful place called The Last Green Valley National Heritage Corridor. I hope you’ll join me and so many other dedicated people as we care for, enjoy and pass it on.

Bill Reid is the Chief Ranger of The Last Green Valley National Heritage Corridor and has lived in the region for more than 35 years. He can be reached at



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