The rains came, and limits on outside water use stayed
So far this summer at least 22 communities south of Boston have limited residents' water use, despite a rainier-than-average July.
Summer rains have little effect on the fundamental calculus that leads to water restrictions. The precipitation evaporates, gets absorbed by plants, and runs down storm-water drains in torrential bursts, having less effect on water supply than in other seasons. And in many communities, residents use significantly more water in the summer.
Dedham, Duxbury, Kingston, Norwell, Pembroke, Plymouth, and Westwood all had voluntary restrictions as of July 31, according to the state Department of Environmental Protection. That means residents were asked to limit watering to certain hours of the day, or alternate days of the week.
Mandatory restrictions, requiring residents to follow limitations on out side watering, or complete prohibitions, were in effect in 15 communities: They include: Abington, Braintree, Bridgewater, Foxborough, Halifax, Hanover, Hanson, Mansfield, Marion, Middleborough, Raynham, Rockland, Sharon, Walpole, and Wareham.
Outdoor watering restrictions go into effect because "demand exceeds pump capacity," said Richard Clark, superintendent of the Halifax Water Department.
Mandatory restrictions ban sprinklers in Halifax. Without such restrictions, Clark said, constant pumping of well water could stress the system and compromise water quality.
In most cases, officials said, the reasons for restrictions relate to infrastructure rather than supply. Ground water may be abundant because of rain, but a municipal water system only has only so many wells, tanks, or reservoirs.
In Bridgewater, which gets its water from a well system, a mandatory outdoor watering restriction bans all but hand-held watering in order to keep enough water on hand for fire protection.
In Braintree, which gets all its water from a reservoir shared with Randolph and Holbrook, rainfall has significantly increased supply, although mandatory restrictions still are in effect. The town is currently in phase one of its drought management plan (no lawn sprinklers), but "we're in great shape this year" compared with last, said Lou Dutton, assistant superintendent for the town water works.
Water restrictions are year-round in Braintree because the capacity of the reservoir limits how much water can be supplied to residents, Dutton said. To provide the additional water for residents water lawns, fill pools, and wash cars during the summer, the town would have to increase its capacity.
In Duxbury, where seasonal water use rises from 27 million gallons in February to 73 million in August, voluntary watering restrictions have nothing to do with supply (the town's aquifer), water and sewer superintendent Paul Anderson said, but "with our infrastructure's ability to provide water at peak demand times." A rainy period doesn't increase supply, Anderson said, but it does reduce demand.
Statewide conservation standards, increasingly emphasized by state regulators, are another reason for outside watering restrictions.
"The DEP is after us for water conservation," Clark said, pointing to the state's requirement that all public water suppliers submit plans to meet the statewide consumption standard of 65 gallons per person per day. Many regional communities are typically well above that standard during the summer.
In Plymouth, where water consumption increases to 84 gallons per person per day in the summer, one of the main reasons for the town's voluntary water restrictions this year is the need to work toward its conservation goals, said public works director Roger Hammond.
"We're trying to decrease water use," Hammond said.
New DEP regulations scheduled to go into effect next year may make communities work harder on conservation. The DEP is requiring all towns to submit drought management plans - likely to include outdoor watering restrictions - this summer. As of next May, if a drought advisory is declared for one or more regions, all public water suppliers within that region must implement those plans, according to DEP spokesman Joe Ferson.
Last year, a drought was declared for most of the state, including the southeast region. Though there have been no drought advisories this summer, if one occurs next year, some communities unaccustomed to water restrictions may face a request - or a command - to turn the sprinklers off.
Robert Knox can be contacted at rc.knox@gmail.com. 