Case Study: Water and Wastewater Utilities Planning for Climate Change CITY OF NORFOLK, VIRGINIA Background As the second largest water utility in the Commonwealth of Virginia, the city of Norfolk provides drinking water to approximately one million customers. The city of Norfolk also provides treated and raw water to the city of Chesapeake, treated water to the U.S. Navy and the city of Virginia Beach and water to other customers during periods of drought. In addition, the city of Norfolk has contracts with the Western Tidewater Water Authority to provide drinking water for two additional locations in the future. Located on the Atlantic coast, the city of Norfolk's system is large and geographically diverse. Multiple water sources include several large reservoirs in the cities of Suffolk, Norfolk, Virginia Beach and Isle of Wight County; four deep wells in the city of Suffolk and two river intakes that transfer water to the reservoirs in the city of Suffolk. Climate Threats Historically, flooding and drought have been concerns for Norfolk. Flooding from intense precipitation events as well as coastal storm surge, exacerbated by high tide conditions, could challenge utility operations. During past extreme events, the water treatment plant has remained dry but access to their facilities and power supply has become problematic. The city is also concerned about the impact of flooding on their backup generators and its effect on aeration in the reservoirs. Planning Process Using the U.S. Environmental Protection Agency's Climate Resilience Evaluation and Awareness Tool (CREAT), the city of Norfolk conducted an assessment of the impacts from a high flow event to their reservoirs west of the city and from a coastal storm surge event to the water treatment plants in the city. The CREAT assessment brought together individuals from various departments within the city of Norfolk to think critically about potential climate impacts, prioritize assets and consider possible adaptation options. Adaptation Measures The city of Norfolk considered the potential consequences of coastal storm surge and other water quality and water quantity-related impacts on their utility infrastructure and operations. To assess each of these potential threats, the city considered how potential adaptive measures would help lower consequences. See the table below for potential adaptive measures that were considered. City of Norfolk, Virginia Case Study — Page 1 SEPA ------- Case Study: Water and Wastewater Utilities Planning for Climate Change TYPE POTENTIAL ADAPTIVE MEASURES Installation of a static barrier such as a berm to mitigate the impacts of flooding Coastal storm surge Safe yield Raising equipment to a higher elevation to mitigate the impacts of flooding Flood-proofing facility doors to protect electrical infrastructure during flooding events The use of temporary barriers such as sand bags to protect facilities and electrical infrastructure during flooding events Water loss prevention Essential use only Low flow fixtures Variable rates for use Contact Information For more information regarding the city of Norfolk's climate adaptation planning, contact David Rosenthal at david.rosenthal@norfolk.gov. City of Norfolk, Virginia Case Study — Page 2 &EPA Office of Water (4608T) EPA 800-Q-15-006 December 2015 ------- |