Massachusetts water restrictions and the Greater Boston exception

Quick WaterBans update

So far we've onboarded about 10 states on WaterBans, our goal of course being a repository of all water restrictions for every town in the USA. We've focused mainly in the Northeast and Midwest, but we're expanding faster as we get the right processes in place to collect and handle all the data.

Massachusetts restriction map

Taking a break from data collection, I decided to create a visualization of the restrictions in Massachusetts. MA at this point is our most restricted state, with over half the towns having some form of restriction. I was surprised that most towns around Boston are entirely free of restrictions. It's interesting that the most populous area is doing the best with water.

No restrictionVoluntaryUse limitsWatering scheduleSchedule + limitsOutdoor ban

Massachusetts water supply map

After some quick research, the reason is that the areas around Boston are supplied by the Massachusetts Water Resources Authority. As seen below, 28 of the 31 systems identified as MWRA suppliers are in municipalities with no restrictions at all. MWRA draws from the huge Quabbin and Wachusett reservoirs, which held about 394 billion gallons on August 1, 2026. Despite drought conditions across much of Massachusetts, the state said the MWRA system was not experiencing drought conditions.

Not in a mapped community systemMWRAGroundwaterSurface waterMixed sourcesSource not reported

What makes it a drought

Water systems outside MWRA operate at a much smaller scale. Worcester and Cambridge show two different ways that can play out.

Worcester is where this gets a little weird. It gets its water from ten surface reservoirs in Leicester, Paxton, Rutland, Holden, and Princeton. Together they can hold a little over 7 billion gallons, led by Lynde Brook Reservoir and the Holden system. On August 11, Worcester reported its reservoirs at 101.1% of capacity while the city was under a Level 2 Significant Drought and banning nonessential outdoor water use.

It turns out those two numbers are measuring different things. The state's drought level covers the whole Central Region and looks at groundwater, streamflow, soil conditions, and long-term rainfall—not just the water stored in Worcester's reservoirs. Worcester then uses that regional declaration to trigger restrictions under its own drought plan. So the city is not imposing a ban because it is about to run out of drinking water. It is conserving early in case the dry weather continues. A full reservoir is also less security than it sounds: Worcester can store a little over 7 billion gallons but treats more than 8 billion gallons in a year, so it still needs rain and runoff to keep replenishing the system. (Worcester supply; current drought status; how Massachusetts measures drought; Worcester drought ordinance)

Cambridge is the other case. It normally relies on its own chain of Hobbs Brook Reservoir, Stony Brook Reservoir, and Fresh Pond rather than MWRA. The three can hold about 4.4 billion gallons when full. On August 24, the public gauge for Stony Brook showed about 355 million of its 418 million gallons, or roughly 85%. That number covers only one reservoir, not the whole Cambridge system. The city says the combined system remains low and in deficit, and Cambridge is under a Level 2 Significant Drought with nearly all nonessential outdoor use banned. (Cambridge supply; drought status; Stony Brook gauge)

These examples are why the restriction map is not simply a map of how much water remains. Cambridge is managing a local supply deficit. Worcester's restriction is a preventive response to a regional drought even though its own reservoirs are full. MWRA's much larger, shared system can absorb the same dry weather for longer before reaching its own drought thresholds.