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Water Supply and Demand
Massachusetts Water Resources Authority

 

MWRA and the Department of Conservation and Recreation keep a daily watch on reservoir levels at Quabbin (412 billion gallon capacity) and Wachusett (65 billion).

While Wachusett levels are kept relatively fixed, Quabbin levels fluctuate with precipitation and watershed runoff.

Ware River stream flows are also watched daily to determine if seasonal transfers to Quabbin during high-flow periods are possible. To gauge current system status, water supply planners have identified six reservoir status conditions that allow for normal monthly fluctuation.

The Quabbin/Wachusett system is so large that it can withstand short- and medium-length droughts and dry periods without a significant impact on its operating levels.

MANAGING DEMAND

WATER SYSTEM DEMAND

In 2013, water system demand was 202.78 million gallons per day, average (mgd/avg) *preliminary

2012 194.7 mgd/avg
2011 196.6 mgd/avg
2010 204.3 mgd/avg
2009 194.3 mgd/avg
2008 205.6 mgd/avg
2007 219.9 mgd/avg

 

 

 

 

 

 

Information on water use, system yield, watershed precipitation and levels of the Quabbin Reservoir are tracked on a daily and monthly basis. Based on a detailed analysis of major factors affecting water demand, MWRA projects that system demand will remain well below 300 million gallons per day.

A review of recent demand and supply conditions (PDF), presented to the MWRA Board of Directors in January 2012, provides more detail on long term trends.

SAFE YIELD

MWRA's SAFE YIELD
MWRA's source reservoirs, the Quabbin and Wachusett, can be counted on to safely provide about 300 million gallons per day of water even during periods of extended drought. This amount is called the "safe yield."


 

 

 

 

 

 

For a 20-year period from 1969 to 1988, the customers of MWRA (and its predecessor MDC) routinely drew more than the safe yield.

The chart Water System Demand 1980-2011 demonstrates this historical trend. Fortunately, precipitation was great enough throughout these years to avoid a major water supply crisis. To address this problem, MWRA launched an aggressive water conservation program in 1986. By 1989, withdrawals had been brought below the safe yield, where they have remained ever since.

WATER SUPPLY STATISTICS

quabbin reservoir photo

The Quabbin Reservoir
larger image

MONTHLY WATER SUPPLY
STATUS REPORT

WATER SYSTEM DEMAND

In August, 2014

overall demand on the MWRA system was 227.33
million gallons per day


Archive

QUABBIN RESERVOIR LEVELS

On September 1, 2014

Elevation: 526.57 feet
Volume: 385,875 million gallons
Capacity: 93.6%


Archive

WACHUSETT RESERVOIR LEVELS

On September 1, 2014

Elevation: 390.45 feet
Volume: 59,753 million gallons
Capacity: 90.9%


Archive

PRECIPITATION

August, 2014
monthly total


Quabbin watershed: 03.84 in.
Wachusett watershed: 03.60 in.


Archive

COMMUNITY WATER USE
Community Use Data

Monthly and year-to-date water use comparisons for MWRA communities

Most Recent Report and Archive

MWRA WATER DEMAND vs. SAFE YIELD 1980-2011

mwra water system demand 1980-2011

larger image


This reduction in average water use was achieved through:

  • Vigorous leak detection and repair efforts on MWRA and community pipes
  • Retrofitting 370,000 homes with low-flow plumbing devices
  • A Water Management Program for area businesses, municipal buildings and nonprofit organizations
  • Extensive public information and school education programs
  • A change in the state plumbing code requiring new toilets to be 1.6 gallon per flush
  • Meter improvements that helped track and analyze community water use
  • New water-efficient technology that has created reductions in residential use
  • Water pipeline replacement and rehabilitation projects throughout the MWRA and community systems.


SOURCE RESERVOIRS

Active Source Reservoirs
MWRA's two source reservoirs, the Quabbin and Wachusett, can store 477 billion gallons of water for everyday use. Actual levels fluctuate.

 

 

 


WATER SYSTEM STORAGE

Source Reservoirs: 477 billion gallons
  Quabbin Reservoir: 412 billion gallons
Wachusett Reservoir: 65 billion gallons

Archive of Quabbin Reservoir Levels
Archive of Wachusett Reservoir Levels

Active Supplemental Supply
MWRA stores treated water in covered tanks across its service area. Water can also be drawn from the Ware River if needed.

Covered Storage Facilities - 262.7 million gallons
 

Norumbega (Weston): 115 million gallons
Carroll
(Marlborough): 45 million gallons
Nash Hill
(Ludlow): 25 million gallons
Blue Hills (Milton): 20 million gallons
Fells (Stoneham): 20 million gallons
Loring Road (Weston): 20 million gallons
Arlington (Arlington): 2 million gallons
Bear Hill (Stoneham): 6 million gallons
Bellevue (Boston/West Roxbury): 3.7 million gallons
Deer Island (Boston/Deer Island): 2 million gallons
Turkey Hill (Arlington):2 million gallons
Walnut Hill (Lexington): 2 million gallons)

In contruction: Spot Pond (Stoneham): 20 million gallons (2014)

Ware River Withdrawals - amount varies
  Water can be drawn from the Ware River if needed. When the Ware River flow is above 85 mgd during the period from October 15 to June 15, withdrawals are sent to the Quabbin Reservoir.

Emergency Back-up Sources and Storage
MWRA maintains a system of back-up reservoirs at points throughout its system for emergency use.

Emergency Backup Sources and Distribution Storage
Back-up Supply Sources: 7.7 billion gallons
 

Sudbury Reservoir (Sudbury): 7.2 billion gallons
Framingham Reservoir #3 (Framingham): 500 million gallons

Back-up Distribution Storage: 2,917 million gallons
 

Spot Pond (Stoneham): 1.9 million gallons
Chestnut Hill Reservoir (Boston/Newton): 500 million gallons
Norumbega Open Reservoir (Weston): 200 million gallons
Weston Reservoir (Weston): 200 million gallons
Fells Open Reservoir (Stoneham): 67 million gallons
Schenck's Pond (Weston): 50 million gallons


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Updated September 5, 2014

Historic Withdrawls Reservoir Levels