EPA Flood Resilience: A Basic Guide for Water and Wastewater Utilities
The U.S. Environmental Protection Agency (EPA) developed this guide to help drinking water and wastewater utilities become more resilient to flooding. In the approach, the utility would examine the threat of flooding, determine impacts to utility assets and identify cost-effective mitigation options. A simple, 4-step assessment process is outlined to help water utilities understand their flooding vulnerability and identify practical mitigation options to protect critical assets. The guide is particularly useful for small and medium utilities.
The four steps of the guide are:
- understand the threat of flooding;
- identify vulnerable assets and determine consequences;
- identify and evaluate mitigation measures; and
- develop plan to implement mitigation measures.
Each step has supplementary resources, including worksheets, instructional videos based on a pilot project, and flood maps to help utilities through the process. These materials allow utilities to customize the guide to their unique needs and constraints.
This approach was successfully tested during a pilot project at a small drinking water system, the Berwick Water Department (BWD), in Berwick, Maine. Using FEMA floodplain information and incorporating future uncertainties such as land use changes, urban development and climate change, BWD characterized the impact of three flood levels (100-year flood, 500-year flood, and a 500-year flood plus 2 feet freeboard). The utility operators and engineers estimated the costs to repair/replace flooded assets and determined the potential impacts to operations. The pilot project is detailed within the report with more information about short and long-term mitigation options chosen by BWD.
The guide can help drinking water and wastewater utilities prevent flooding-caused damage to pumps, disconnected chemical tanks, broken distribution lines, and disrupted power supply. Examples of measures to mitigate vulnerabilities range from replacing existing pumps with submersible pumps to installing backflow preventers on low-lying overflow pipes to protect finished water to elevating electrical controls.
Publication Date: September 2014
- Assessment guide
- Planning guides