If you really use your imagination, this sounds a little bit like Niagara Falls. But it's just the Moody Street Dam, where the Charles River isn't always so thunderous.
"Literally, at times in the summertime, particularly in August and early September, this would be a trickle coming over this dam," said Bob Zimmerman, executive director of the Charles River Watershed Association. "And there are times where it doesn't flow at all."
When rivers run low, that threatens the wildlife that depend on the rivers for survival. So Zimmerman says states need to get serious about limiting how much water is taken out of streams and rivers for human use.
"If we don't do that," he cautioned, "these rivers are going to seriously suffer, and we really will run into a shortage-of-water problem."
We get drinking water from many places, including wells and reservoirs, such as the Quabbin. But we also get it from rivers and streams, where we share it with fish.
That isn't easy. For one thing, stream flow isn't a constant. When snow melts in the spring, rivers rise. In the heat of the summer, they slow down — yet that's when people want the most water.
And it's when our systems have pumped rivers dry.
"That really is not acceptable," said Laurie Burt, commissioner of the Massachusetts Department of Environmental Protection.
"The challenge," she added, "is how do we make sure that doesn't happen, but that we are also providing water when it's needed and where it's needed?"
Four prominent conservation groups recently resigned from a state panel in Massachusetts because of a new policy they said could let rivers turn to mud. They rejoined after Burt's office rescinded that policy.
"What we urgently need, and has been needed for a very long time," Burt said, "is to be able to predict how much water can safely be withdrawn from a river basin."
Thousands of fish were killed because rivers were pumped dry in Massachusetts and Connecticut. Some reservoirs in New York are dangerously low. In Maine, Vermont and New Hampshire, snow-making takes millions of gallons of water from streams and rivers.
And Elizabeth Gara, executive director of the Connecticut Water Works Association, is worried.
"People are so used to turning on the faucet and having a nice, clean, ample supply of water," Gara said, "and they don't understand all of the work and all of the money that goes into making sure that that water is coming to them in that way."
Connecticut has proposed new rules that would redirect more water to rivers and streams and less to public use.
But Gara warns this could hamper economic growth and force water utilities to restrict people from filling swimming pools and washing cars.
"We have to be very careful when we deal with water allocation policies that we make sure that when we're trying to protect aquatic life," Gara said, "that we don't do that to the detriment of human life."
But some states are already imposing tough restrictions.
Vermont, for example, regulates how much water ski resorts can divert. Maine sets a minimum flow for its streams and rivers. And Massachusetts is working to define the amount of water that can be taken safely from its waterways.
Mark Smith of the Nature Conservancy says more states should consider these kinds of steps.
"As I like to say, fish can't hold their breath," Smith said. "So even if [a river] is just dry for a day or two, and that's not natural, it really can cause fish kills and very dramatic outcomes."
Of course, a lot of money — millions of dollars — has gone into reservoirs and water treatment facilities. So if restoring a dry river means removing a dam or decommissioning a treatment plant, that's probably going to cause a big fight.
But Smith says some communities have taken those dramatic measures. Case in point: the town of Reading stopped using its wells because they were sucking too much water out of the Ipswich River.
"It's often pitted as fish versus people, or people versus fish," Smith said. "But the issue that we're working on is how to make it an 'and' statement — that it's water for people and water for nature, and how do you really figure that out?"
For now, there's no one answer. It's a long-term question that the federal government lets the states decide. But it's important to resolve because — even in this water-rich region — demand threatens supply.
This program aired on January 5, 2010.