anchor Description
This project supports the development of a Comprehensive Flood Management Plan (CFMP) for Montgomery County.The CFPM will improve the County's ability to address flooding based on scientific and engineering data and use a comprehensive, coordinated approach to identify potentially affected residents and businesses, particularly underserved communities and businesses that are least prepared to respond to and recover from flooding events. The CFPM will, among other things: gather data on historic flooding in the County, including input from affected communities; examine the potential impacts of climate change and other significant factors that can cause flooding in the County, including the effect of updated rainfall predictions; provide recommendations for regulatory, policy, and organizational changes necessary for the County to comprehensively plan for, respond to, and recover from flooding events; and include detailed hydrologic and hydraulic modeling, vulnerability assessments, and the development of adaptation/mitigation design plans.Typical tasks in the development of specific watershed/sub-watershed assessments may include evaluations of current risk, future risk due to climate change, and assessment of risk due to aging assets. More specifically, the effort will include identifying areas at risk of flooding, quantifying that risk, developing mitigation alternatives, and conducting cost-benefit analyses, including evaluation of impacts to disadvantaged communities. Additional results will include development of prioritized capital improvement program projects and implementation schedules. The level of detail and budget required to accomplish these tasks will vary by watershed. There are major watersheds and almost smaller watersheds in the County. This study will complement the State's efforts under Stormwater Management Law, Environment Article which requires the Maryland Department of the Environment (MDE) to report on the most recent precipitation data available, investigate flooding events since and update Maryland's stormwater quantity management standards for flood control.
anchorEstimated Schedule
Phase will identify watersheds for detailed modeling in Phase and provide an assessment of current County programs, policies, budgets, and other components of the County's flood management activities. Phase I was completed in May Modeling of specific watersheds and continued analysis of the County's flood-related programs, policies, etc. began in
anchorCost Change
Costs increase so that all planned watersheds can be analyzed.
anchor Justification
Flooding incidents in Montgomery County have been increasing in frequency and severity for several years. The built environment also affects flooding. An April report from the Office of Legislative Oversight (OLO) identified an upward trend of urban flooding in the County, from two to four occurrences a year before to to occurrences per-year since and that the severity has increased in terms of property damage and loss of life. According to the U.S. Environmental Protection Agency, precipitation in Maryland has increased by about percent in the last century but precipitation from extremely heavy storms has increased in the eastern United States by more than percent since To determine the best way to address flooding problems, the County needs a systematic watershed and sub-watershed-based analysis of flooding, a better understanding of the impact the County will experience from increased rainfall linked to climate change, and other significant contributing factors.
anchorFiscal Note
In addition to County support, the Department of Environmental Protection will pursue outside funding to fund these efforts. An supplemental added Current Revenue: General for the amount of includes a funding switch to reduce Intergovernmental and increase Current Revenue: WQP, including from prior appropriation. In is shifted from the Implementation of the Comprehensive Flood Management Plan project.
anchorCoordination
Department of Permitting Services, Office of Emergency Management and Homeland Security, Department of Transportation, Montgomery County Fire and Rescue Service, Maryland-National Capital Park and Planning Commission, Maryland Department of the Environment, U.S. Army Corps of Engineers