f respiratory disease, allergies and asthma among building residents, leading to lower absenteeism and higher productivity. Including land development standards in greenbuild projects will increase these healthy-environment benefits. Positive social interaction is another benefit we can expect to find when landscapes are designed with well-being in mind. For example, the presence of tree and grass cover was tied to lower crime rates in a 2003 study of urban Chicago from the Journal of Arboriculture.
Tremendous advantages to energy and resource conservation are linked to sustainable sites as well. In developing its recommended practices, the Sustainable Sites Initiative has rethought many of the traditional uses of water, soils, plants and materials in site design. The practices it recommends instead are intended to restore our ecosystem’s ability to regulate itself, and in the process, reduce environmental damage.
In the past, landscape design has treated rainwater as a waste product, using large drainage systems that dumped water rapidly into creeks and rivers, causing flooding and erosion and severely reducing the absorption of groundwater needed to keep soil healthy. This rapid runoff is often contaminated by the weed killers and fertilizers used to feed and maintain installed landscapes, which has downstream effects on wildlife and recreation. On the other side of the equation, high-quality municipal drinking water—in shorter supply all the time—is used to irrigate gardens and lawns.
|JAJ Landscape Architectural Services of Houston has just completed LEED Certified Landscape Design and Installation for Walnut Bend Elementary, Houston Independent School District’s first LEED accredited elementary school. Environmentally friendly materials were used including native plants and recycled materials.|
How would Sustainable Sites address these issues of water waste and pollution? Instead of draining contaminated water away, landscape designers are encouraged to provide vegetated swales and filter strips to both clean and slow down water runoff. This slowed water can be harvested and used in place of municipal drinking water in irrigation systems, fountains and custodial applications. Water infiltration can be a built-in feature of landscape plans, by incorporating rain gardens and vegetated catchment areas to capture excess water.
The author is a U.S. Green Building Council LEED Accredited Professional and a member of the American Society of Landscape Architects.