CRWA in the News

Dry spell leaves Charles River low 

By Ralph Ranalli, Globe Staff

Boston Globe, Sunday, September 9, 2007

Pressure from development in the outer western suburbs and the recent dry spell have dropped water levels in the Charles River to their lowest point in 16 years, prompting concern among conservationists about increased pollution levels and damage to fish and wildlife populations.

Measurements taken last weekend at a state water-level-monitoring station in Dover registered a flow rate of 7.7 cubic feet per second. While flow rates vary widely due to seasonal and weather conditions, the Dover gauge has registered a reading that low only a dozen times in the 71 years that flow rates on the river have been monitored and recorded, Charles River Watershed Association senior engineer Nigel Pickering said last week.

"At first we thought it was just a normal dry period, but this is something different," Pickering said. "Some stretches of the river are pretty close to dry right now."

The low water levels have raised alarm about the health of the river's wildlife and prompted the association to issue an e-mail call to its water-quality monitoring volunteers to help document the situation. Volunteers like Terry Stone of Newton were asked last week to swap their buckets and sample jars for digital cameras, to help identify stretches of the river that might be in particular trouble.

"They were looking for people to take pictures of some of the features of the river that aren't normally above water," said Stone, a lawyer whose house sits about 300 feet from the river in Newtonville and who regularly fishes the banks with his son Kiernan.

"It was very low," he said. "If you looked at Cheesecake Brook [a tributary of the Charles that runs through Newtonville], it looked like Cheesecake Beach."

A brief inspection by a Globe West reporter confirmed Stone's observations. Not far from his house, state Department of Conservation and Recreation officials recently built a $2 million suspension bridge to allow pedestrians and cyclists to cross the river into Watertown. Late last week, a person on foot could have easily traversed the river just a few dozen yards from the bridge wearing a $15 pair of knee-length rubber boots.

Further down the river into the Charles River Basin, low freshwater flows don't necessarily affect water levels, but do cause sea water from Boston Harbor to rush in to fill the void, further stressing freshwater species. In extreme low flow periods like the current one, Pickering said, the so-called salt wedge - the leading edge of the heavier salt water that pushes the lighter fresh water up and back - can reach as far upriver as the Watertown dam.

Anna Eleria, a watershed association project manager who specializes in fish populations, said the extreme low flows and water levels have a negative effect on wildlife in several ways. Less water, she said, means higher concentrations of pollutants in the water and, therefore, in fish, which in turn are eaten by other wildlife like herons, other birds, and turtles.

The low flows also stress populations of such fish as brook trout, who live and feed in the fast-moving sections of the river, and make it difficult for migratory fish such as blueback herring, shad, and alewives to travel down the river to the ocean. The timing of the current situation is particularly bad, Eleria said, because her group and the US Fish and Wildlife Service are in the second year of a project to restore American shad fry to the Charles.

"It's something we're pretty concerned about," she said of the program.

Even fish like largemouth bass, sunfish, and American eels, which prefer the relatively static waters of the river, are being stressed by the low conditions, she said, by being bunched closer together and forced to compete more aggressively for food. The low water levels also magnify the negative effect of recent algae blooms in the river, which stress fish populations by creating a wild pendulum effect on oxygen and carbon-dioxide levels, she said.

Pickering said officials are becoming increasingly concerned about development along the river in outer suburbs like Milford, Dover, Medway, and Lincoln.

Development and population increases in those suburbs have lowered levels of ground water that would otherwise make up part of the river flows during periods of little or no rain. Development also increases the amount of rain water diverted into storm drains, where it bypasses the natural ground-water and river systems. Pickering said that state and federal officials, as well as the association, are working to promote tougher water-use restrictions and alternate storm-water management plans that will prevent extreme low water levels in the river.

"We would like everyone to share the pain," he said. "Both the fish and the people."