Water Resources Research Act Program

Details for Project ID 2018WV233B

Evaluating the state of dam infrastructure under a changing climate

Institute: West Virginia
Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $16,767 Total Non-Federal Funds: $38,461

Principal Investigators: Leslie Hopkinson, John Quaranta

Abstract: West Virginia has over 600 dams that were primarily constructed before 1970 and are nearing the end of the 50-year design life. While the dams are primarily constructed as earthen dams for flood control, some reservoirs may be considered as secondary water sources. Rehabilitation will be necessary to address potential health and safety concerns. There are two important design criteria for flood control infrastructure: probable maximum precipitation (PMP) and the 100-year design storm. PMP represents the greatest precipitation amount that could occur at a specific location and specific time of year. Analyzing extreme storms are part of the process to define PMP, but no extreme storms in almost 40 years have been included for the West Virginia analysis. In addition, orographic (topography) effects are likely significant in WV, so additional investigation is needed. The 100-year storm is rainfall expected to occur once on average in 100 years. Methods to determine these design storms assume a stationary climate, and the more-frequent extreme events need to be considered. The proposed work will evaluate these two important infrastructure design criteria under a changing climate in the steep terrain of West Virginia. Associated safety impacts will also be considered. Specific objectives and tasks include the following: Objective 1: Evaluate dam design criteria under a changing climate within the Central Appalachian ecoregion. Task 1.1: Identify field site and available data, Task 1.2: Complete site specific PMP analysis for a location of a high hazard dam, Task 1.3 Estimate the 100-year design storm under changing climate, Task 1.4 Calculate Probable Maximum Flood (PMF) hydrograph. Objective 2. Assess dam safety impacts due to reservoir pool elevation changes. Task 2.1: Determine the initiator or reservoir pool elevation level which triggers changes in hydrostatic and seepage forces on the dam structure, Task 2.2: Identify the failure mechanisms likely to occur and structure a step-by-step progression which may lead to a dam breach, Task 2.3 Analyze the dam and identify the “more likely” and “less likely” factors as parametric input data from adverse weather conditions. Results from this effort will benefit the ongoing dam safety rehabilitation efforts in West Virginia. Dam safety issues can occur when there are changes to the structural loading. Examples of safety issues are increasing rises in pool elevation that saturate the upstream dam face, increasing internal structural seepage forces and rates, that may lead to reductions in the factor of safety for slope stability. Evaluating the reservoir pool elevation changes to modified PMP loading is necessary to build the case for investigating risk reduction measures to the dam and spillway structures. The work will result in a technical presentation and paper, training of students, and technical transfer with state agencies.