Montgomery County Comprehensive Flood Management Plan

The County is working to develop a Comprehensive Flood Management Plan that will aid long-term strategic planning for flood mitigation. Download the flooding flyers:

Comprehensive Flood Management Plan Community Forum October 2022

Watch the Video on YouTube

Why a Flood Management Plan?

Montgomery County has experienced an increase in flooding events causing impacts to public and private property. While the reasons for this increase are varied, increases to impervious surface due to development and increases in high-intensity rainfall events are some of the top reasons. The impacts of both are expected to increase due to continued growth and climate change.

The Montgomery County Department of Environmental Protection (DEP) is in the process of developing a Comprehensive Flood Management Plan. A flood management plan lays out the steps by which the County can develop the information to inform and ultimately address this growing risk. This plan will consist of several phases of work, panning the next few years, vulnerability assessments, detailed flood studies, adaptation design, and implementation of mitigation project and programmatic responses.

What are the Sources of Flooding in Montgomery County?

Urban Pluvial Flooding

Flooding in the county can occur due to local rainfall runoff exceeding the capacity of the local storm drainage system or infiltration capacity of the ground. This is termed (pluvial) flooding, otherwise known as "urban flooding".

Intense rainfall can cause flooding if runoff accumulates and cannot be removed quickly enough by storm drains. Urban flooding areas are typically not mapped.

Riverine Flooding

Flooding can also occur due to stream or river levels exceeding the banks. This type of flooding is known as riverine flooding. Impacts from either of these sources can range from life hazard to nuisance impacts.

Water levels in a stream or river rise and can cause flooding by overtopping banks or bridges. Some riverine flooding areas are mapped through FEMA or County studies

Flood Safety Tips

  1. 6 inches of moving water will knock you off your feet.
  2. 1 foot of water will float vehicles.
  3. Do not attempt to drive through a flooded road.
  4. Turn off your electricity and gas.