Nashville Water Services: Metro Water Authority, Billing, and Infrastructure
Nashville's Metro Water Services department functions as the public utility responsible for drinking water supply, wastewater treatment, and stormwater management across Davidson County. Understanding how this authority operates — its billing structure, infrastructure responsibilities, and service boundaries — matters practically for residential customers, commercial property owners, developers, and anyone navigating permit or infrastructure questions tied to water connections. This page covers the department's scope, operational mechanics, typical service scenarios, and the boundaries that distinguish Metro Water Services from adjacent jurisdictions and agencies.
Definition and scope
Metro Water Services (MWS) is a department of the Metropolitan Government of Nashville and Davidson County, operating under the consolidated city-county government established in 1963. The department provides 3 core utility functions: potable water distribution, wastewater (sanitary sewer) collection and treatment, and stormwater management. As of the most recent service figures published by MWS, the system serves approximately 200,000 metered water accounts and processes more than 60 million gallons of wastewater per day through its treatment facilities, including the Central Treatment Plant on the Cumberland River (Metro Water Services, Nashville).
Scope and coverage: MWS jurisdiction covers Davidson County — the geographic footprint of the Metro Nashville consolidated government. Service does not extend to adjacent counties such as Williamson, Rutherford, Wilson, or Sumner, which are served by their own municipal or utility district systems. Properties on the immediate county boundary may receive service from a neighboring utility district rather than MWS, depending on existing service territory agreements. Tennessee law governing utility districts (Tennessee Code Annotated Title 7, Chapter 82) establishes how such territories are defined and protected, meaning MWS cannot unilaterally extend service into an established utility district's territory even where physical infrastructure would otherwise permit it.
This page covers the Metro Nashville water authority and its Davidson County operations. It does not address state-level water quality regulation by the Tennessee Department of Environment and Conservation, federal Safe Drinking Water Act compliance administered by the EPA, or private well and septic systems that operate outside the public utility network.
How it works
MWS operates through three functionally distinct program areas:
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Water distribution — Raw water is drawn from the Cumberland River at two intake facilities, treated at the K.R. Harrington Water Treatment Plant (capacity: 120 million gallons per day) and the Omohundro Water Treatment Plant (capacity: 60 million gallons per day), then distributed through approximately 2,400 miles of water mains across Davidson County.
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Wastewater collection and treatment — Sanitary sewage flows through roughly 2,800 miles of sewer lines to treatment facilities, where it undergoes primary, secondary, and tertiary treatment before discharge. MWS operates under a National Pollutant Discharge Elimination System (NPDES) permit issued by the Tennessee Department of Environment and Conservation, which sets effluent limits enforced at the federal level through the Clean Water Act.
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Stormwater management — Stormwater is managed separately from sanitary sewer under a Municipal Separate Storm Sewer System (MS4) permit. This distinction matters for billing: customers receive a stormwater fee on their utility bill calculated based on impervious surface area (measured in Equivalent Residential Units, or ERUs), not water consumption volume.
Billing mechanics: MWS issues monthly utility bills combining water consumption charges, sewer charges (typically calculated as a percentage of metered water use), and the flat stormwater fee. Rates are set by the Metro Council through the annual budget process — a connection to broader Nashville Metro Budget decisions that directly affects utility rate structures. Water consumption is measured in hundred cubic feet (CCF); 1 CCF equals approximately 748 gallons. Residential accounts with a standard 5/8-inch meter are subject to a base availability charge regardless of consumption.
New connections to the MWS system require a tap fee and, for larger developments, may trigger capacity review under MWS infrastructure planning protocols. Developers pursuing large projects should coordinate with both MWS and the Nashville Metro Planning Commission to identify infrastructure constraints early.
Common scenarios
Residential billing disputes: The most frequent customer service issue involves unexpectedly high water bills, typically caused by running toilets, leaking irrigation systems, or failed pressure regulators. MWS offers a one-time leak adjustment credit for qualifying accounts — the customer must document repair, and the adjustment applies to the excess consumption above the prior 12-month average.
Service interruptions: Planned outages for main repairs are communicated via the MWS online outage map. Emergency breaks — Nashville's distribution system includes pipes dating to the early 20th century in older neighborhoods — can require same-day emergency response. MWS maintains a 24-hour emergency line for active main breaks.
New construction connections: A developer building a subdivision requires a developer extension agreement with MWS before infrastructure design is finalized. This process establishes whether the developer builds and dedicates infrastructure to MWS or whether MWS constructs and assesses costs. Connection to public water and sewer is typically required by Metro Nashville code for properties within the service area, which intersects with Nashville Building Permits and Nashville Zoning and Land Use approvals.
Stormwater compliance: Commercial and industrial properties that disturb more than 1 acre of land during construction must obtain a Construction General Permit from TDEC in addition to satisfying MWS stormwater requirements. Post-construction, properties with significant impervious cover may be subject to enhanced stormwater management plan requirements.
Decision boundaries
The boundary between MWS responsibility and private property owner responsibility is the meter — specifically, the point of connection between the public main and the private service line. MWS owns and maintains the meter, the meter vault, and all infrastructure on the public side. The property owner is responsible for the service line from the meter to the structure and all plumbing within the building.
A comparison of two common account types illustrates how billing rules differ:
| Account Type | Sewer Charge Basis | Stormwater Fee Basis | Meter Size Options |
|---|---|---|---|
| Residential (single-family) | % of water consumption | 1 ERU (flat) | 5/8" standard |
| Commercial/Industrial | % of water consumption or separate discharge meter | ERUs calculated from impervious surface survey | 3/4" through 6"+ |
For accounts where a commercial facility has significant outdoor water use (irrigation, cooling towers) that does not enter the sewer, a separate irrigation meter can be installed. Sewer charges are not applied to flows through an irrigation-only meter, a significant cost consideration for large commercial properties with substantial landscaping.
Infrastructure disputes between MWS and adjacent utility districts are resolved under Tennessee utility district law, not Metro Nashville ordinance. Property owners in boundary areas should verify their service provider before assuming MWS handles their account — a check available through the MWS online address lookup tool or the broader Nashville Metro Departments directory. For a full orientation to how Metro Nashville government functions across all service areas, the Nashville Metro Authority index provides a reference point for understanding how departments like MWS fit within the consolidated government structure.
References
- Metro Water Services — Metropolitan Government of Nashville and Davidson County
- Tennessee Department of Environment and Conservation — Water Programs
- Tennessee Code Annotated Title 7, Chapter 82 — Utility Districts
- U.S. EPA — National Pollutant Discharge Elimination System (NPDES)
- U.S. EPA — Safe Drinking Water Act
- U.S. EPA — Municipal Separate Storm Sewer Systems (MS4)