Skip to main content

Heading Off Stormwater

New construction has added little to campus stormwater, analysis shows

When Duke builds an engineering complex, museum or other new structure, it often builds over earth that once helped absorb the water that flows across campus during a storm. But a recent analysis shows Duke has expanded its campus significantly in recent years with minimal increases in its stormwater runoff.

Duke planners carried out the analysis while developing a comprehensive approach to promote the university's environmental goal of preventing increases in the volume of campus stormwater and of the pollutants, such as fertilizer runoff, that the water may contain.

Developed by the Facilities Management Department (FMD), the new Stormwater Management Plan will help Duke meet local, state and federal regulations for stormwater discharges. Campus architects, engineers and others will use it in their planning, and city officials will gain a new tool to help them review Duke's compliance with regulations.

"We consider stormwater carefully whenever we undertake a project," said FMD's acting director, Glenn Reynolds. For instance, when we closed off part of Science Drive for the CIEMAS construction, we narrowed the road and replaced part of it with trees and plantings, which improved both the landscaping and the absorption of stormwater. We're always looking for ways to move that water into our own ground and treatment systems instead of to the city."

The plan's key feature is a map of campus watershed boundaries, drainage features, storm sewers and impervious surface areas that don't absorb rainwater. The map includes heavily developed areas such as West Campus, as well as the mixed-development Central Campus, the East Campus and the Washington-Duke Inn and Golf Course. FMD developed the map by combining existing electronic maps of the campus with drainage system maps from the City of Durham and topographic maps from Durham County.

City rules state that no development or redevelopment may increase the volume, rate or "pollutant load" of stormwater by more than 10 percent above the March 1997 level when the rules were established. FMD therefore designed the new map to show Duke's structures and other conditions in 1997, providing a baseline against which to assess subsequent development.

With the new map in hand, Duke planners compared stormwater runoff in 1997 with current conditions, following the city's public works guidelines. Their analysis showed campus development totaling less than 2 percent more than the 1997 rate -- much less than the 10 percent increment allowed -- with no adverse impact on any roadway, residence or drainage structure.

"We've done projections that include all current and planned construction, and we think things will remain under control well into the future, although we're also looking at contingency plans in case stormwater increases," Reynolds said.

FMD officials regard the new map as part of a broader process of environmental planning for the campus. They hope it will also provide a useful tool for city officials and others interested in supporting Duke's growth while safeguarding the local environment.