Seven towns plot how to protect aquifer

Limited and low-impact development seen as key

Now that seven area towns have put together a plan to protect the Plymouth-Carver aquifer, the largest underground water resource in Eastern Massachusetts, it's up to the individual communities atop the huge aquifer to put the plan into effect.

With seasonal water bans beginning and parts of the state experiencing chronic water restrictions, representatives of the seven towns that depend on the underground water basin met at a summit in Wareham this month.

They unveiled tools, such as restrictions on development, that officials and residents can enact to help preserve the resource.

"A lot of people underrate the importance of water, especially in New England," said Carver Selectman Dick Ward, who attended the Wareham conference.

"We have plentiful water, though not necessarily in the future."

The Plymouth-Carver aquifer holds an estimated 500 billion gallons and is the sole source of drinking water for Plymouth and Carver. The aquifer also stretches under most of Wareham, Kingston, and Plympton, the mainland portion of Bourne, and a corner of Middleborough.

To protect the aquifer's water quality, the towns must keep the region's "recharge" areas free from overdevelopment, said Robb Johnson, director of the Nature Conservancy's Plymouth program.

Given the area's conjunction of plentiful water and large tracts of open, buildable land, development remains the aquifer's biggest threat, he said. The paving that comes with construction reduces the ground area through which rainwater is filtered and cleansed as it flows back into the aquifer.

"The issue here is acting while things are in relatively good shape," Johnson said, "not just for human use but for wildlife and ecological balance."

With the help of a consultant, the aquifer committee developed a regional open space plan that identified land parcels that have the greatest potential for recharging the aquifer. The plan maps the aquifer with emphasis on protecting lands around current and potential future well sites; it also gives towns a rating system to evaluate parcels for protection.

A second objective of the aquifer committee is the local adoption of rules such as a "low-impact" development bylaw, which encourages development that does not disturb natural hydrology, Johnson said.

Low-impact rules require swales (low areas) and pervious (porous) pavers, rather than pavement, to gather rainwater and allow it to naturally purify as it is absorbed directly back into the earth. It's a different approach, Johnson said, from conventional engineering, which channels rainwater along paved gutters to storm drains - a route that makes it vulnerable to pollution. .

"This is an idea gaining frequency around the region," Johnson said, adding rhetorically, "Can we take it further in this area?"

Another model bylaw would create rules for earth removal - excavating sand and gravel for a new cranberry bog, or mining it to sell - that protect ground water by mandating a protective gravel buffer over the aquifer. Without a buffer, Carver selectman Ward pointed out, earth removal operations can create "a new opening for aquifer pollution."

But it's up to the towns to preserve key recharge areas and put protective bylaws into effect. Carver remains "a little cautious," Ward said, of regional efforts. As his town begins to build its first municipal water system on town property in North Carver, local residents see their first priority as protecting water sources.

Their worry, Ward said, is that private landowners might seek to sell the aquifer's water. On the plus side, Carver has recently passed a comprehensive earth removal bylaw that provides protection for ground water.

Wareham residents are also worried that the aquifer's abundance of water makes it a target for outside entities - either public or private - seeking to take drinking water out of the region. "One of my biggest fears is people taking our water and bottling it and sending it off," said Wareham Selectwoman Brenda Eckstrom.

But Eckstrom said regional cooperation to protect water quality is a major goal for her town, which lies downstream from other aquifer towns. "It's one of the universal concerns," she said. "It's way bigger than politics."

Recognizing that action on aquifer protective measures - through open space acquisitions, new bylaws, or updating of community open space plans - remains in the hands of the individual towns, the committee will next discuss choosing one issue on which to push for action, Johnson said.

The aquifer protection committee's next meeting is July 10 at Carver Town Hall at 7.

Robert Knox can be contacted at rc.knox@gmail.com.