The house the bay built

Every time it rains, buildings in the Chesapeake Bay watershed contribute to the bay's pollution. The culprit is stormwater runoff. Our impervious, hardscaped environment acts as a funnel for contaminants that speed down the sewer system into streams and lakes, eventually emptying into the Chesapeake. There just isn't enough greenery in the built environment to act as a natural filter for all the runoff.

An important part of the path toward a healthier bay is to let the bay "build" the houses of the watershed — to design and construct bay-friendly homes. This summer, we're doing just that.


Our University of Maryland Solar Decathlon 2011 team is building an innovative home carefully designed and engineered to capture and filter stormwater and greywater, as well as harvest energy from the sun. We call it "WaterShed," because we see it as a model for a cleaner, smarter, more effective way to design buildings for both solar energy generation and stormwater management.

WaterShed is Maryland's entry into the U.S. Department of Energy's Solar Decathlon 2011, an international competition challenging 20 student teams to design and build houses powered entirely by the sun. Our house goes beyond the Decathlon's requirements, uniquely aiming to address not only the issues of energy use within the built environment, but also rising concerns about water quality. (The competition will take place in Washington from Sept. 23 to Oct. 2.)


The Chesapeake Bay is the largest estuary in the United States, home to more than 3,600 plant, fish and animal species. Water runoff from the nearly 17 million human inhabitants of the Chesapeake Bay watershed, supported by 64,000 square miles of cities, towns, power plants and farms, upsets the subtle ecological balance of the bay in catastrophic ways. Runoff contains chemicals, fertilizers and pharmaceutical drug residues that set the bay's fragile nutrient and salinity balance off kilter. Decades of deterioration of the bay make clear the need for innovation in the built environment.

Not all 17 million Chesapeake Bay watershed residents are from Maryland or Virginia. Upstream from our communities, people as far north as New York are creating runoff that makes its way to us. All parts of the bay watershed, across political jurisdictions, must be willing to work collaboratively to improve the built environment to stem the runoff.

This is a complex problem to address, but we believe that our innovation and public education is a constructive place to begin. By designing the built environment to manage runoff on site, filter pollutants from greywater and minimize water usage, we can improve conditions for those downstream and help protect the bay.

With this in mind, WaterShed's principal design features include:

•A split-butterfly roof, well-suited to capture and use both sunlight and rainwater;

•Constructed wetlands that filter stormwater and greywater (household water with limited contaminants);

•A green roof to retain rainwater and promote efficient cooling;

•A photovoltaic array to harvest enough solar energy to power WaterShed year-round;

•A solar thermal array to fulfill all domestic hot water needs;

•"Edible landscapes" that support community-based agriculture;

•Patent-pending indoor, liquid desiccant waterfall for high-efficiency humidity control;

•An efficient, cost-effective, durable and time-tested structural system.


Taken together, these design features make WaterShed less thirsty for fossil fuels than standard homes and less dependent on costly water purifying infrastructure. The house acts as a micro-ecosystem that encourages residents to live a more sustainable lifestyle — not only by conserving but also by capturing and reusing natural resources.

Even if only a few of these principles were applied to building projects throughout the watershed, we could make a significant impact on the Chesapeake Bay. Think of our work as a demonstration project.

Turning these principles into a functioning building is a collaborative enterprise involving a team of roughly 200 students from many schools and colleges across the University of Maryland campus. Maryland businesses and professional groups are providing significant mentoring and support as well. Together, we're forging Maryland's next generation of sustainable designers, gaining the skills and experience to help create a better built environment for a better bay.

You can try our vision on for size this September at the Solar Decathlon in Washington's West Potomac Park, where our ideas will undergo a rigorous examination by a panel of experts. The ultimate test, though, is public acceptance. Learn how the buildings you live, work and play in every day could help ease water pollution. Ask yourself whether you could live in the house the bay built.

Leah Davies (daviesln@umd.edu) and Allison Wilson (amwilson@umd.edu) are University of Maryland student leaders of the school's Maryland's Solar Decathlon 2011 Team. Website: http://2011.solarteam.org/team.

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