Blue Plains Wastewater Facility in Washington DC Reinforces Facility Against Floods

Blue Plains Wastewater Facility in Washington DC Reinforces Facility Against Floods

Project Summary

View of Blue Plains Wastewater Facility along the Potomac River.
View of Blue Plains Wastewater Facility along the Potomac River.

The District of Columbia's Blue Plains Wastewater Facility in Washington, D.C., serves most of the national capital area, including parts of Maryland and Virginia. This facility is vulnerable to flooding because of its location adjacent to the Potomac River. The facility has historically been protected from flooding by a seawall built to withstand a 1-100 year flood. However, understanding that storms may become more frequent and intense, the DC Water and Sewer Authority decided to implement an adaptation action to prepare for more flooding due to climate change. The Blue Plains facility is undergoing a $13 million dollar construction project, expected completion in 2021, to build a 17.2 ft high sea wall that will surpass the recommended 1-500 year storm level by including three feet of freeboard to protect against higher river elevation or wave action. Blue Plains has selected this standard as a proxy to adapt the facility to expected higher river elevation and storm surge inundation. This will help protect the facility against higher river levels and storm surges and reduce threats of Clean Water Act violations. Blue Plains took this action to promote resilience to current conditions and adapt to expected climate changes.

Implementation

First, Blue Plains identified facility vulnerability and appropriate adaptation options. They acknowledged the scientific uncertainty of how climate change would impact water levels in the Potomac River. As a major facility with a large investment along the riverfront, building a seawall to protect against flooding was deemed a preferable strategy rather than moving the entire facility to higher ground.

Blue Plains chose an adaptation action that exceeded current best practices to account for future changes in climate.Blue Plains utilized a proxy measurement to design the seawall to account for uncertainty regarding how climate change would impact Potomac River levels. The seawall (currently under construction) was designed to account for an expected 1-500 year flood and include three feet of freeboard, a design that exceeds FEMA’s flood risk standards for federally funded projects.

Similar Case Studies

  • Several other communities have adapted to protect their water and wastewater service from flooding and sea level rise. To see how another northeastern community analyzed the impact of sea level rise on a water utility, view the Manchester-by-the-Sea case study.
  • For a community that recognized the prohibitive cost of protecting a highly vulnerable facility and decided to move to a safer facility, see the Iowa City case study.
  • Protecting the Blue Plains facility is only one of several strategies Washington, D.C. has taken to reduce the threat of flooding on the community. To see how Washington, D.C. is using green infrastructure to reduce stormwater impacts and combined sewer overflows view the DC Consent Decree case study.