|STAGGE, J. - Utah State University|
Submitted to: Journal Hydrologic Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2017
Publication Date: 9/13/2017
Citation: Stagge, J., Moglen, G.E. 2017. Water resources adaptation to climate and demand change in the Potomac river. Journal Hydrologic Engineering. https://doi.org/10.1061/(ASCE)HE.1943-5584.0001579.
Interpretive Summary: The future of water resources supply and demand in the Potomac river basin is examined. Stresses to the system from both changing supply driven by climate change and changing demand from population growth are a concern in this river basin. An evolutionary algorithm approach is taken to optimize reservoir operating rules across multiple objectives. Stresses to the system are mitigated by these optimized operating rules, but greater collaboration and flexibility are required by water users in Maryland, Virginia, and Washington, DC. This approach can be used as a template for future water resources planning in different land use settings and different geographic locations.
Technical Abstract: The effects of climate change are increasingly considered in conjunction with changes in water demand and reservoir sedimentation in forecasts of water supply vulnerability. Here, the relative effects of these factors are evaluated for the Washington, DC metropolitan area water supply for the near future (2010 to 2040) and the far future (2070 to 2099) by repeated water resources model simulations. Adaptation strategies are then developed for the system using a multi-objective evolutionary algorithm. Optimized reservoir management policies were compared a posteriori using six distinct objectives, ranging from reservoir storage to environmental and recreational benefits. Simulations of future conditions show water stress increasing with time. Reservoir sedimentation is projected to more than double (114% increase) the severity of reservoir storage failures by 2040. Increases in water demand and climate change are projected to further stress the system, causing longer periods of low flow for downstream water bodies and a loss of recreational reservoir storage. The adoption of optimized rules mitigates some of these effects, most notably returning simulations of 2070-2099 climate to near historical levels, though these rules require more collaboration and flexibility than the system currently allows.