The operations at each federal reservoir managed by the U.S. Army Corps of Engineers are described in water control plans as documented in water control manuals. These manuals typically outline the regulation schedules for each project, including operating criteria, guidelines and rule curves for varying conditions; and specifications for storage and releases from the reservoirs. The water control manuals also outline the coordination protocol and data collection, management and dissemination associated with routine and specific water management activities such as flood control operations or drought contingency operations.

The authority for Water Control Operations for Corps of Engineers owned and operated reservoir projects is contained in legislative authorization acts and referenced project documents. These public laws and project documents usually contain provisions for the development of water control plans, and appropriate revision thereto, under the discretionary authority of the Chief of Engineers. In addition, Section 7 of the Flood Control Act of 1944 provides that: "On and after December 22, 1944, it shall be the duty of the Secretary of the Army to prescribe regulations for the use of storage allocated for flood control or navigation at all reservoirs constructed wholly or in part with Federal funds provided on the basis of such purposes, and the operation of any such project shall be in accordance with such regulations:…" (33 USC 709). "Blanket" congressional authorizations which apply to all federal reservoir projects.

• Flood Control Act of 1944 (P.L. 78-534)
• Water Supply Act of 1958 (P.L. 85-500)
• Fish and Wildlife Coordination Act of 1958 (P.L. 85-624)
• Federal Water Pollution Control Act Amendments of 1972 (P.L. 92-500)
• Endangered Species Act of 1973 (P.L. 93-205)
• Water Resource Development Acts

Corps regulation in support of Flood Control and Navigation for non-federal projects (FERC license, MOAs, etc.).

Without a comprehensive updated WCM, the Corps runs the risk of, among other things: adversely affecting water quality downstream; not providing sufficient water where needed (when needed to meet the authorized purposes of the projects and the needs of stakeholders, whether domestic, municipal or industrial); adversely affecting endangered species; and expending water resources too early, which reduces the ability to maintain the system to meet project purposes and the needs of stakeholders; and flooding people and facilities that are now within flood plains. This risk is due to changing conditions within the basin and at Federal reservoirs which, if not accounted for, can affect water management decisions.

Hydrologists must consider and evaluate many factors to determine the appropriate management of water at each lake. In addition to the constraints of the authorized purposes, they must also consider power contract commitments, hydrologic and climatologic factors, downstream lake and basin wide conditions, potential threats of flood and drought, and lake levels.