The owners of the Great Stone Dam in Lawrence recently lowered the crest gate — a long structure that runs along the top of the dam — to complete repair work, causing the river to suddenly drop about five vertical feet. The crest gate was temporarily raised to control the downstream current of Tropical Storm Ida, which contributed to a mild rise in water levels, but most of that excess flow has now ended. The work on the crest gate is expected to be completed today, Friday, Sept. 10, before the gate will be raised and the level of the river will rise back.

On the topic of water levels, local scientists and environmental organizations are studying the impact of rain on regions like the Merrimack Valley. As this past July was one of the rainiest months on record. This large amount of rainfall has contributed to multiple Combined Sewage Overflow (CSO) events. CSOs occur when combined sewer systems discharge excess wastewater directly into nearby streams, introducing toxic materials to the natural environment. According to Policy and Education Specialist John Macone of the Merrimack River Watershed Council (MRWC), there were 10 days in July when CSOs occurred, which is an unusually high number, and roughly 200 million gallons of CSO waste entered the Merrimack. “Scientists believe that as climate change occurs, the kind of heavy rainfall that we saw in July will be a more common event, and thus the river will see more CSO events and more pollution,” says Macone.

Organizations like the MRWC and Clean River Project are still working hard to fix CSO problems and prohibit pollutants from entering the river.

When the current comes downriver, workers and volunteers associated with the Clean River Project — a nonprofit organization that cleans and preserves a 45-mile stretch of the Merrimack River — go through and count every piece of trash they collect. According to Kristin Bachmann, who works part-time at the organization, their boats are custom-built because they are needed to perform specific jobs. The “River Monster” — so-called due to its enormous power — is one such vessel. It can pull out engines or bicycles that have been dumped and left behind. Roughly 84 cars have been pulled out of the riverbanks due to the efforts of the Clean River Project.

On Saturday, Sept. 18, the Merrimack River Watershed Council is hosting its first annual Save Our River Festival in Newburyport. There will be live music, barbecue and even a cornhole tournament. Click here to learn more.