How Community Assessments Work
MWRA is a "wholesaler" to its member communities.
MWRA's charges ("community assessments") typically represent about 45% of the amount that communities bill their customers. The proportion varies considerably among communities.
Latest MWRA Community Assessments
Final FY2025 wholesale assessments to communities (PDF)
Posted June 26, 2024
MWRA Water and Sewer Rate Methodology
How MWRA sets water and sewer assessments to for communities:
Water Rates
In setting water rates, MWRA first identifies through its budgeting process the total amount of revenue that must be raised to run the water system. Charges are calculated using a flat rate per million gallons – $4,991.08 for FY2025 – times the metered water use by a community in the last full calendar year.
Sewer Rates
Sewer charges are computed on a proportional allocation basis utilizing total flow, contributing population and census population for each community. The total amount of required revenue for the sewer system is allocated either to operating costs or capital costs. Operating costs are allocated to each community based on the average of the prior three calendar years’ total flow, with adjustments for strength of flow.
Capital costs, including debt service, are allocated to each community based on a combination of (1) average of the prior three years’ peak month wastewater flow and average concentrations of total suspended solids and biochemical oxygen demand; (2) the proportion of the population of the community that is served by the local sewer system; and (3) the proportion of the community’s U.S. census population to the total census population in the sewer system.
If You Have Questions About Your Bill
If you live in an MWRA community, your water and sewer bills come from from your local water and/or sewer department. If you have questions or concerns about your water/sewer bill, you should contact your local water/sewer department.
Retail Rates
Each community has its own rate structure and accounting policies. The MWRA Advisory Board publishes an Annual Retail Rate Survey.