J. Percy Priest Lake photo with dam in foreground

Water Information

Decisions that involve water are of interest to diverse stakeholders that share an appreciation of the many services that the Great Lakes, rivers, reservoirs, and other aquatic systems provide. 

The Corps is the largest water management organization in the nation. The Corps operates a varied suite of water infrastructure (e.g., storage reservoirs, diversions, pump stations, reregulation facilities, and navigation locks) and is increasingly asked to assess how that infrastructure might be operated to provide additional and increasingly diverse benefits to society, including more effective ecological stewardship, reduced environmental impact, and greater recreation opportunities.

The role of water managers is to manage water and conflict in the short-term and to help steer system operations to a sustainable optimized state of management in the long-term.

Flood Risk Management (FRM) is one of USACE Civil Work’s three core missions, alongside support for commercial navigation and restoration of aquatic ecosystems. USACE’s FRM activities seek to reduce the threat to life and property from riverine and coastal storm flooding through the development and communication of advanced knowledge, technology and solutions.

USACE FRM activities are rooted in partnering with local, state, tribal, and federal agencies, as well as the private sector and other stakeholders. FRM is a shared responsibility, and USACE works with partners to design, construct, operate, and maintain projects that manage flood risk across the nation. 

Although efforts of federal agencies, state and local governments, and tribal nations have reduced flood risk, flooding still accounts for 90% of all-natural disaster damage. To reduce flood risk, the Great Lakes and Ohio River Division operates and maintains 84 dams and reservoirs to protect communities in the region. When a storm hits, multi-purpose flood-control reservoirs built and maintained by the Corps of Engineers retain excess water upstream of the dam. Controlled releases of this excess water helps prevent or reduce downstream flooding. The majority of our dams are within the flood-prone Ohio River basin. The Division also has 539 miles of levees and over 100 local flood protection projects, which include walls, levees and channel improvements. These projects have saved lives, homes, businesses and prevented over $39 billion in damages since 2012.

What is flood risk?

Flood risk is a combination of the likelihood of a natural or man-made flood hazard happening and the consequences or impact if it occurred. Flood risk is dependent on a source of flooding (such as a river), a route for the flood water to take, and damages caused by the flood (such as damage to homes and businesses).  Managing flood risk starts with understanding the chance that certain hazards could occur and then identifying the corresponding magnitude of the potential outcome. If any flood risk management structures exist, such as a dam or levee, the performance of those structures also needs to be considered when determining flood risk. Although FRM structures provide some level of protection, they do not eliminate flood risks. Flooding can still occur in surrounding communities and watersheds even with flood risk management measures (structural and non-structural) in place.

Navigation was the Army Corps of Engineers’ earliest Civil Works mission, and the Great Lakes & Ohio River Division maintains a robust navigation mission to this day. The Corps provides safe, reliable, efficient, and environmentally sustainable waterborne transportation systems (channels, harbors, and waterways) for movement of commerce, national security needs, and recreation.

Annually, the Great Lakes facilitate transport of 175 million tons of vital commodities to and from the Nation’s heartland. The Ohio River and its tributaries carry 35% percent of the country’s waterborne commerce.

The Division also hosts the Corps' Inland Navigation Planning Center of Expertise.


The U.S. Army Corps of Engineers Hydropower Program stands as the largest producer of hydropower in the United States, boasting 75 power-producing dams accommodating 356 individual generating units. USACE's hydropower assets yield over 70 billion kilowatt-hours annually, constituting a substantial source of clean and renewable energy. This quantity of clean energy is sufficient to power ten cities comparable in size to Seattle. Furthermore, the revenue generated by the USACE hydropower fleet is utilized to reimburse the original construction expenses of the hydropower projects and to support the operation, maintenance, and modernization investments of the hydropower fleet.

Chick Lock

Through deeds, not words, we are BUILDING STRONG®