The authority for water control operations for USACE-owned and operated reservoir projects is contained in legislative authorization acts and referenced project documents. The public laws and project documents contain provisions for the development of a Master Water Control Manual and specific project Water Control Manuals, and appropriate revisions and updates. A number of congressional authorizations apply to all federal reservoir projects, including the following:
- 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
The purpose and need for this update of the Water Control Manual is to determine how the federal projects in the ACT Basin should update operations for their authorized purposes, in light of current conditions and applicable law, and to implement those operations through updated water control plans and manuals. The action will result in updated plans and manuals that comply with existing USACE regulations and reflect operations under existing congressional authorizations, taking into account changes in basin hydrology and demands from years of growth and development, new/rehabilitated structural features, legal developments, and environmental issues.
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 project purposes, they must consider power contract commitments, hydrologic and climatologic factors, downstream lake and basin-wide conditions, potential threats of flood and drought, and lake levels.
Without a comprehensive updated Water Control Manual, USACE runs the risk of, among other things, not providing sufficient water where needed (when needed to meet the authorized project purposes and the needs of stakeholders, whether domestic, municipal, or industrial); adversely affecting endangered species; 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.
USACE regulations also provide specific policy and guidance for inclusion of drought contingency plans as part of USACE’s overall water control management activities. This update includes a proposed drought plan for the basin developed in collaboration with APC. In addition to operations at USACE projects in the ACT basin, flood risk management operations at four APC projects (Weiss, H. Neely Henry, Logan Martin, and R.L. Harris) would be updated in their respective water control manuals.
Through this action the USACE is not proposing to build, install, or upgrade any facilities nor is the USACE proposing to modify any authorized project purpose via this action, although the extent to which some can be achieved may be affected. This action is limited to the way reservoir levels are managed and water is released from them.