Three students of engineering, water management and environmental science are winners in a new international competition for proposals to advance sustainability in coastal cities.

The competition targeted upcoming water-resources professionals and was part of the run-up to an “H209” symposium to be held Sept. 9-10 at Liberty Science Center in Jersey City, N.J. The event is a forum for water-management professionals and coincides with joint Dutch and New York celebrations of the 400th anniversary of the explorer Henry Hudson’s landfall in New York.

The winners survived two rounds of competition and will present their papers on Sept. 9.

First prize went to Anke Poelstra, a senior studying water-resource management at Delft University of Technology in the Netherlands. Her plan for a rainwater collection and storage system for toilet flushing, if widely employed in the Netherlands, would save about 17.5 million liters of potable water per day.

Ellen Speace, a sophomore environmental science major at Rutgers University, New Brunswick, N.J., took second prize with a proposal to use hydrodynamic separators to collect and purify stormwater runoff. Her plan proposes 65 blocks of New York City’s Lower Manhattan as a test site, served by 10 separators with an estimated equipment cost of $850,000.

Brendan McKeon, a sophomore civil engineering major at Columbia University, New York City, won third prize with a plan of local government incentives for green roofs on residences. McKeon says such incentives are missing in sustainable water-management planning.

Angela Haines, executive director of the “Henry Hudson 400” events, says entries were judged on creativity, viability, presentation and methodology. She says the submissions greatly improved in the second round, as judges sought greater detail. In addition to cash prizes, winners will be matched up with firms for internships next summer. In developing the program, Haines says planners “really wanted to focus on ‘Who are the water managers of the future?’ ”