Rule Curves in Flood Control Reservoirs: A Historical and Procedural Analysis

Author(s): Mower, E.; Miranda, L.

The U.S. Army Corps of Engineers (USACE) manages 11 million ha of federal land and water including hundreds of multi-purpose reservoirs. Managing the water regime in many of these reservoirs requires establishing seasonal targets in water levels (i.e. rule curves) that are dependent on regional precipitation patterns and water demands from user groups. Rule curves in Northern Mississippi reservoirs were established in 1967 as an answer to increased interest in multi-purpose water storage. Rule curves have been modified in past years attempting to balance various environmental concerns such as emphasis on fish and wildlife management mandated in USACE reservoirs by federal legislation, and water needs such as flood control and agriculture use. The processes and challenges associated with developing and amending rule curves are complicated and generally unknown to most fish and wildlife managers and user groups. Informing managers and user groups about the process required could lead to effective communication, management, research, and collaboration. Thus we sought to review the processes, policies and laws the USACE follows in developing and amending rule curves that govern water levels, focusing on the four large flood control reservoirs in the Upper Yazoo Basin. To this end we reviewed the history of the rule curves, as well federal policies and laws governing them. We obtained our information from a literature review and interviews with agency personnel having current or past involvement in managing these flood control reservoirs. Congressional authorization, feasibility studies and justification studies are some requirements that must be met before a rule curve can be established or modified. National Environmental Policy compliance must be shown, as well as flood risk impacts both upstream and downstream for flood control reservoirs. Magnitude of the rule curve change determines congressional involvement in amending rule curves. Although our results are preliminary, they provide a window into a little-understood but important component of fish and wildlife management in reservoirs.

Go back


Technical Sessions

1 Best Management Practices #1
2 Delta Water Assessment
3 Flood Assessment & Mgmt.
4 Wetlands
5 Watershed Mgmt. #1
6 Non-Point Source Assessment
7 Modeling
8 Water Quality
9 Best Mgt. Practices #2
10 Delta Water Conservation
11 Sedimentation
12 Storm Water
13 Watershed Mgt. #2
14 Public Water Systems
15 Surface Water Assessment & Evaluation

Click here to view the entire agenda