Merrimack River on list of 10 most threatened rivers in U.S.

Monitor staff
Tuesday, April 12, 2016

When a national organization added the Merrimack River to its list of the 10 most threatened rivers in America, its concern wasn’t one big thing but a whole lot of little things. You’re probably sitting underneath one of those things right now.

“It’s not just pavement, it’s also roofs; anything that water can’t pass through,” said Michele Tremblay, chairwoman of the Upper Merrimack River Local Advisory Council [sic]. “Rain hits it, takes anything along for the ride – petroleum, animal waste, fertilizers, failed septic systems – and off it goes into the nearest brook or stream.

“It’s like a ‘fun slide’ for contaminants,” she said.

American Rivers, a national advocacy group, annually lists 10 rivers it thinks are most endangered. This year’s list includes rivers that flow through 15 states and face threats such as pollution from mountaintop-removal mining in West Virginia and too much water being removed by cities and farmers in California.

For the Merrimack River, which flows from central New Hampshire through northeastern Massachusetts, the problem is more diverse: development that creates impervious surfaces. Roads, parking lots, warehouses and homes all keep rain from seeping into the ground when it hits but instead direct it somewhere else, sometimes creating flooding, sometimes harming underground aquifers that aren’t getting replenished, sometimes carrying pollutants into the river.

“Pavement is rapidly replacing trees across the Merrimack River watershed . . . (and) is the largest threat that the Merrimack River watershed faces today. The U.S. Forest Service ranks the Merrimack River watershed as the most threatened in the country due to the development of forest lands,” writes the group in its report, “2016 America’s Most Endangered Rivers.”

Tackling development and other “non-point-source” causes of water pollution can be difficult, because it involves changes that affect many people, such as new zoning regulations or limitations on fertilizer usage, as compared with something like improving a deficient wastewater treatment plant.

“It is easier to go after the big discharge – I call them the elephants,” Tremblay said. “They’re big, you get an elephant gun. But this is like ants, and we’re all ants, that’s the challenging part.”

American Rivers, in its report, urges the Environmental Protection Agency “to create a regional watershed team and implement key safeguards including protection for important forest lands along rivers and streams, green infrastructure solutions, and improved stormwater management to reduce the excess nutrients and pathogens in the river.”

It points to similar teams in other places facing water quality challenges, including the Chesapeake Bay, Great Lakes and Gulf of Mexico, and also specifically to work in Lawrence, Mass.

The Merrimack River starts in Franklin, where the Pemigewasset and Winnipesaukee rivers join together, and flows 117 miles south into Massachusetts and then east, emptying into the Atlantic Ocean at Newburyport, Mass. The watershed – the total region where any water ends up in the Merrimack River, and thus where development can affect water quality – includes both the Pemigewasset and Winnipesaukee rivers as well as the Contoocook River, a major tributary and thus covers more than half of New Hampshire. The watershed extends north into the White Mountains and west to the edge of the Connecticut River Valley.

(David Brooks can be reached at 369-3313 or or on Twitter @GraniteGeek)