Reduced rainfall in Massachusetts and parts of the Northeast since May has pushed Cambridge’s local reservoirs to their lowest volume in at least 10 years, driving the city to purchase millions of dollars of water.

Cambridge has used $3.6 million of the Cambridge Water Department’s water fund to purchase three months’ worth of water from the Massachusetts Water Resources Authority, according to Sam Corda, the managing director of the Cambridge Water Department.

As of last Thursday, the U.S. Drought Monitor indicated that northeastern Massachusetts, including the Cambridge and Boston area, remained in a state of “extreme drought,” which is the index’s second highest level of drought severity.



Since Oct. 11, the water delivered to Cambridge residents has consisted of 90 percent water from the MWRA and 10 percent from Cambridge’s own water system, according to Corda.

Cambridge maintains its own water system, which includes the Hobbs Brook Reservoir, Stony Brook Reservoir, and Fresh Pond Reservoir. Combined, the three reservoirs hold up to approximately 4.4 billion gallons of water and can last eight months when full, but have recently only been filled to 25 percent of total capacity, Corda said.

Unlike the Cambridge water supply, the MWRA system continues to operate at normal levels. Corda said that, as a MWRA member, Cambridge has been able to access the regional supply, but at a higher cost.

“The costs to produce our own water versus the cost to buy water from the MWRA is a 2:1 ratio,” Corda said. He added that the economic impact on consumers will depend on the drought’s duration, but could affect water bills in the next fiscal year.

“We’re going to continue doing the 90:10 [ratio] until our reservoirs are recovered some, and at some point, we’re hoping that we continue to get rain and minimize the MWRA water costs, because obviously, that’s a significant cost for us,” Corda stated.

Corda said short-term weather forecasts from the National Oceanic and Atmospheric Administration predict continued drought conditions for the next three months, but that long-term forecasts predict higher-than-average rainfall for the last quarter of 2017.

Kenneth Strzepek, an adjunct professor at the Kennedy School who specializes in water resource management, said the combination of Cambridge’s local water system and its membership in the MWRA has enabled Cambridge to maintain its water supply amidst a “serious condition.”

“I think that Cambridge has done a pretty good job, they’ve developed a system that’s quite robust,” Strzepek said. He contrasted Cambridge’s MWRA membership with other U.S. municipalities that dropped their membership from regional water supplies and were then unable to immediately purchase water from regional systems during emergencies.


“If you look at Flint, Michigan… Flint was trying to save money and pulled out of their existing system, and when they had a problem, the other system wouldn’t let them back in,” Strzepek stated.

Corda said that, in response to the drought, Cambridge has cut municipal outdoor irrigation by 50 percent and implemented water conservation initiatives. While conservation guidelines for residents and institutions are currently “strongly recommended,” Corda said these recommendations could become “mandatory” restrictions in the spring, depending on drought conditions.

In an emailed statement, Colin Durrant, a spokesperson for the Harvard Office for Sustainability, indicated the University was aware of the drought.