At a Glance

Aesthetically pleasing and environmentally friendly water infrastructure recycles wastewater and returns stormwater to the natural environment.

Project Description

Sidwell Friends School (SFS) is deeply committed to practicing responsible environmental stewardship with curriculum grounded in learning about the natural world and their relationship to it. When the school decided to construct a new Middle School building, sustainable design was a logical expression of institutional values. Working with an integrated design team that included Kieran Timberlake Associates LLP, Andropogon Associates LTD, and JFW Project Management, Biohabitats contributed heavily to the water infrastructure. Biohabitats designed the wastewater and stormwater systems for the school, incorporating the design into the school yard and entrance. The final designs helped earn a LEED Platinum certification (first K-12 school in the world), an “AlA Top Ten” award and admiration of more than 10,000 visitors, since its construction.

The stormwater system captures runoff from a green roof, directs it through a series of artistic flow forms to a pond. The flow form sculpture welcomes visitors and aerates the water to support a healthy ecosystem for pond plants and animals. The pond, with access steps, doubles as an outdoor classroom. A small recirculation pump sends water back to the flow form for continual treatment and appeal. As rain water enters the system, the pond overflows into a beautiful floodplain that infiltrates water into the natural environment.

A 3,000 gallons-per-day wastewater system captures all wastewater from the building and cleans it through a series of natural treatment steps that mimic natural ecologies. Treatment components include a series of terraced constructed wetland cells, a trickling filter, a recirculating sand filter, and ultra violet (UV) disinfection, all tightly integrated into the building and site. This closed loop system recycles water for toilet flushing and use in cooling towers.

Planting native species and non-invasive adaptive plant varieties preserves local biodiversity and reintroduces natural pathways through the campus allowing birds and other animals to move between the neighboring watersheds of Rock Creek Park to Glover-Archibald Park.

Biohabitats continues to work with the Sidwell Friends School to maintain its environmental leadership through ongoing remote monitoring, quarterly maintenance visits, and technical support and engineering.



Chesapeake/Delaware Bays

Physiographic Province



Rock Creek

Expertise Areas

Infrastructure, Research & Development, Urban Ecology, Water


Sidwell Friends School


Washington, District of Columbia, United States

Project Team
  • Kieran Timberlake Associates LLP
  • Andropogon Associates
  • JFW Project Management