01
About the Utility
The Massachusetts Water Resources Authority is greater Boston’s wholesale water and wastewater provider, established under an enabling act of 1984. It supplies treated water to member communities and operates the regional wastewater transport and treatment system, while the communities maintain local water pipelines and own local sewers. In FY2025 the two systems served approximately 3 million people and more than 5,500 businesses, and water communities had grown to 53. Revenues are budgeted to come overwhelmingly from assessments on these communities, with the Boston Water and Sewer Commission alone expected to provide about 30.1% of combined charges in FY2026.
02
Water System
Supply comes from the Quabbin and Wachusett reservoirs west of Boston, which under present operating rules provide a safe yield of approximately 300 mgd against five-year average withdrawals of 203 mgd. Water is treated at the Carroll Water Treatment Plant and carried by aqueducts and tunnels to the community systems; MWRA reports meeting every state and federal drinking water standard in 2025, though lead sampling placed Boston, Malden and Medford above the Action Level. Storage is the indicator to watch: Quabbin held 82.1% of capacity at the end of FY2026, and the Greenfield Recorder reported 77.6% in late September 2026, Below Normal under MWRA’s drought plan.
03
Wastewater System
Wastewater from 43 communities flows through MWRA’s interceptors and pumping stations to the Deer Island Treatment Plant, which has a strong compliance record: it received NACWA’s Platinum Peak Performance Award for an 18th continuous year in 2024, and the FY2026 budget reported no permit violations for over 18 years. The fourth-quarter FY2026 performance report nevertheless records one violation there that year, alongside five at the Clinton Treatment Plant. Combined sewer overflows remain the legacy issue: by the end of 2024 typical-year discharges had fallen to 401 MG system-wide, but control-plan goals were not met at eight outfalls.
04
Investment & Priorities
Capital planning runs through five-year programmes under Board-approved spending caps, partly financed by green bonds that Fitch and S&P rated AA+ in 2026. The FY26 Capital Improvement Program splits planned FY2026 spending almost equally between wastewater and waterworks and projects $2.0 billion over FY2024–FY2028 against a cap of approximately $1.4 billion, led by asset protection and water system redundancy. Actual capital expenditure since inception passed $9.7 billion by December 2025, and financing costs absorb more than half of budgeted FY2026 expenses.
Combined water and sewer rate revenue
MWRA combined water and sewer rate revenue, $ million, FY2016–FY2025 (fiscal years ending 30 June)
Reported actuals from one ten-year table in the FY2025 Annual Comprehensive Financial Report statistical section.
Sources: MWRA Annual Comprehensive Financial Report for the Fiscal Years Ended June 30, 2025 and 2024, Historical Rate Revenue and Percentage Increases.05
Sustainability & Resilience
MWRA’s latest greenhouse gas inventory reports emissions 41% below 2006 levels, meeting the Commonwealth’s target of a 33% reduction by 2025. Deer Island generates some of its own electricity but purchases most of it, and renewable output fell short of budget in the final quarters of FY2025 and FY2026. MWRA states that it already meets the federal PFAS standards before they take effect, and it funds community lead service line replacement through interest-free loans and grants.
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Key Challenges
- Protecting supply security as Quabbin storage falls, keeping withdrawals within safe yield.
- Delivering water system redundancy while projected spending exceeds the capital cap.
- Reducing lead exposure where community sampling exceeds the Action Level.
- Maintaining Deer Island’s compliance record and closing remaining sewer overflow gaps.
- Managing capital financing costs that absorb over half of budgeted expenses.