Lakes & reservoirs

Who Manages US Reservoirs? Corps, Reclamation, TVA

By the Water Level Atlas team · Last reviewed Oct 21, 2026

Most large US reservoirs are run by one of three federal agencies: the US Army Corps of Engineers (USACE), the Bureau of Reclamation, and the Tennessee Valley Authority (TVA). Many others belong to power companies, cities, water districts or states. The operator decides the lake's target levels and releases, so it is the best place for official information about your lake.

What does the Army Corps of Engineers manage?

USACE builds and operates dams and lakes across the country, organized into regional districts. Its lakes often serve several purposes, such as flood risk management, navigation, hydropower, water supply, recreation, and fish and wildlife.

Each Corps lake has a water control plan (part of a water control manual) that sets how it is operated. The USACE Fort Worth District says there is "no single release formula that applies to every lake" and that, in its district, protecting downstream areas from flooding "takes precedence over all other missions."

The Corps' role can reach beyond its own dams. A 2018 Federal Register notice, for example, describes USACE plans to update the water control manuals for Alabama Power Company's Weiss and Logan Martin reservoirs, because of the Corps' flood risk management responsibilities there.

What does the Bureau of Reclamation manage?

Reclamation works in the 17 western states. It says it has built more than 600 dams and reservoirs, including Hoover Dam and Grand Coulee Dam. Its focus is water delivery and power:

It calls itself "the largest wholesaler of water in the country," serving more than 31 million people.
It supplies irrigation water for 10 million acres of farmland.
It is the second-largest producer of hydroelectric power in the US, with 53 powerplants.

Reclamation's mission, in its own words, is to help meet "the increasing water demands of the West while protecting the environment." Its lakes are run mainly to store and deliver that water.

What does TVA manage?

TVA is a federal hydropower owner, like USACE and Reclamation, and runs a system of dams and reservoirs on the Tennessee River and its tributaries. Its Office of the Inspector General describes how, as directed by the TVA Act, TVA uses this system for "navigation, flood control, power production and, consistent with those purposes, for a wide range of other public benefits."

TVA operates its reservoirs as a connected system using guide curves and flood guides, with lower levels in winter for flood storage and higher levels in summer. In 2004 its Board approved an operating policy, developed with public input, that sets these rules. See guide curves explained and winter drawdown.

What about power companies, cities and states?

Many reservoirs are not federal. Utilities and power companies own a large number of hydropower lakes. The Department of Energy says hydropower projects owned by non-federal entities "typically require a FERC license" (from the Federal Energy Regulatory Commission) for construction and operation. License terms can include operating rules and environmental requirements.

Other reservoirs are owned by cities, water supply districts, irrigation districts or state agencies. Some lakes have more than one party involved, such as a utility-owned lake with Corps flood rules, as in the Alabama Power example above.

How do I find out who runs my lake?

Check the dam name. Searching "[lake name] dam operator" usually turns up the owner.
Look for the operator's lake level page. Most large operators publish lake levels online. USACE runs a national water data site at water.usace.army.mil, and Reclamation's website (usbr.gov) has a Water Operations section.
For utility lakes, look on the power company's website for a lake levels or shoreline management page.
For state or local lakes, check the state water agency or the local water district.

The operator's own notices are the official word on planned drawdowns, refill, closures and flood operations.

Why does the operator matter for lake levels?

Different operators have different priorities, which shape how a lake behaves. A flood-control lake may run low in winter. A water supply reservoir in the West may fall steadily through a dry summer. A hydropower lake may rise and fall daily with power demand. Knowing who runs your lake helps you read the numbers. See why lake levels change.

Using this on Water Level Atlas

Each lake page credits the agency that supplies its data in the page footer. We show "vs full pool" only when that operator publishes a full-pool level on the same datum. For flood status we show NOAA's official information. Browse lakes by state from our US page.