Integrated Assessment of Coastal Hydrologic Hazards to Groundwater, Stormwater, and Wastewater Infrastructure at Coastal Military Facilities
Image credit: DODAbstract
Current approaches for evaluating the impacts of water level rise and changing (intensifying) precipitation patterns on flooding evaluate these phenomena separately, neglecting the ways in which groundwater can link the two hazards and create compound flooding risks in coastal areas. Even when surface flooding does not occur, generally wetter subsurface conditions may have an overlooked impact on aging wastewater collection systems and the ability of the system to treat wastewater as expected. Saltwater intrusion, rising groundwater levels, and changes in recharge patterns may also impact drinking water sources and may increase groundwater contamination from legacy landfills and other pollutant sources. Without a framework for holistically evaluating these threats, DoD may underestimate the risk to coastal facilities and may be unprepared for the actual costs of natural hazards for water infrastructure. In this ESTCP project, we are demonstrating the application of an integrated suite of models to holistically analyze the impacts of common coastal hydrologic hazards (specifically, rising sea and/or groundwater levels, increasing groundwater salinity, and changing precipitation patterns) on groundwater, stormwater, and wastewater infrastructure at US military installations. This modeling toolbox uses site-specific predictions of changing rainfall patterns and rising water levels as inputs to an integrated model (MODFLOW and SWMM) that simulates groundwater flow and salt transport, stormwater and sanitary sewer flow, and stormwater best management practices. The toolbox will also contain coding packages to evaluate impacts to groundwater flooding and stormwater management, wastewater conveyance and treatment, and (where applicable) drinking water quality and groundwater contamination based on outputs from integrated model simulations. Here, we present advances in developing the integrated suite of models and performing a detailed assessment of Dover Air Force Base (demonstration site), as well as findings from a screening level analysis of other Department of Defense settings. Ultimately, this modeling toolbox will allow users to identify, evaluate, and prioritize investment in interventions to sustain water infrastructure systems and thus improve water security while reducing overall cost to the Department of Defense.
Omowumi Erukubami
PhD Candidate
Austin K. Farnum
PhD Student
Dannielle Pratt
Postdoctoral Researcher
