Duke Team Wins Cities of the Future Competition

When asked to peer into the future and come up with a plan to provide water for the residents of Washington, D.C. 100 years from now, a group of four Duke engineering students responded with an imaginative plan to collect and process Team ReUserainwater in 28 towers as wide as a Manhattan city block and 900 feet tall.

Coupled with other technological and policy initiatives, Team ReUse believes that their plan would serve the needs of the projected 2.5 million district residents -- almost four-and-a-half times more people than today -- while keeping the amount of water taken from the current source, the Potomac River basin, at sustainable levels.




In addition to these high-tech towers, their plan also envisions other strategies for commercial and residential buildings Team ReUsewithin the district to capture, process and direct rainwater to appropriate uses.



Team ReUses’s proposal was one of the winners of the recent national “Cities of the Future” competition sponsored by IBM, The History Channel and the American Society of Civil Engineers. Members of the team were all Pratt School of Engineering students with a keen interest in the environment: Laura Hoover, Lee Pearson, Natalia Rossiter-Thornton and Steven Worrell.

The competition began with architectural and designs firms in Washington D.C., San Francisco and Atlanta being invited to imagine what their city of would like in 2108 and to develop plans. Winners of this phase of the competition were selected in January.

In the next phase, teams from universities across the country were asked to come up with systems to accompany each of the three winning architectural concepts in one of three infrastructure areas: water, transportation or energy.

For Team ReUse, the challenge was devising a way to address all facets of water use for the nation’s capitol a century from now – clean water to drink and cook with; water for the sanitation system; water to clean clothes, pots and pans; and irrigation.

Central to the plan are certain mandates for all buildings in the district. Residential and commercial buildings would be required to utilize low-flow technology for all sinks, showers and toilets. Furthermore, all buildings would be required to have partial green roofs, which would collect rainwater for use in irrigation.

“The green roof would have a southward orientation, which decreases storm water runoff and adds insulation to the building,” Pearson explained. “The non-green portions of the roofs would also collect rainwater, which would then be used for washing and laundry machines.”

The water used in sinks, showers and laundries would be filtered of soaps and other chemicals for eventual use in toilets and as irrigation for non-food plants.

“It was difficult to think about what things might be like in one hundred years from now,” said Pearson. “Our strategy was to think about the emerging technologies of today and try to think two or three steps beyond that, assuming that the technologies would be more efficient and inexpensive.”

As an example, the team relied on forward osmosis, a recent technology that has been shown effective in small models to be an efficient purifier of water. They envisioned that this system would be upscaled and placed in the towers, creating water that would be suitable for drinking and irrigating hydroponic gardens.

“In talking with David Needham (professor of mechanical engineering and material sciences), the team thought about bio-inspired designs, leading us to rethink how we treat wastewater,” Pearson said. “Steve Worrell found research on a hydroponic plant that was effective in treating wastewater, allowing us to close the loop in our system. Clean water is processed and leaves the towers, where it is distributed for use in homes and the wastewater returns to be treated by the hydroponic plants.”

A second Duke team, Team Minimize, submitted a transportation plan for Washington, D.C. The team consisted of Lauren Wessel, Nick Menchel, Lindsay Rawot and Joe McMurray.