Low impact development and other design strategies provide value above ground where users can hear, touch, and see how the stormwater moves across space
By Travis Rice
Agencies across the United States are revising the governing regulations for the handling of stormwater before, during, and after a project’s development. Civil engineers and landscape architects are concurrently developing innovative tactics to control both the quantity and quality of stormwater exiting their project sites. Stormwater was once viewed as a necessary evil in project development and maintenance; however, designers now embrace the challenge of finding adequate area to detain all of the stormwater that falls on the project site, while simultaneously incorporating that stormwater as an aesthetic design feature in both public and private locations.
Instead of solely channeling and storing water to meet agency requirements, designers can take advantage of stormwater control features to provide a visual oasis and respite for the many users of public space. Commercial and public space design allows for an opportunity to harness the power of water for its use as a teaching tool, an evolving art piece, or focal point of a landscape concept. These swales, channels, basins, and ponds typically require a substantial amount of site area and often remain dry for several months of the year. Amphitheaters, walking and jogging paths, breakout spaces, and viewing areas can all be built within and around these drainage elements to make for usable public space. Bridges or bridge-like elements can provide opportunities to shape the design of an entire project. Native plants adapted to these fluid conditions can thrive and provide seasonal interest as well as shore up any slopes or channels. The utilization of natural cobble and boulders in novel ways, in lieu of concrete rip-rap, dissipate the energy produced in collecting the site’s stormwater. These riparian-influenced features provide an unusual and unique setting for passers-by to enjoy.
Stormwater regulations are becoming stricter and enforcement more prevalent, given that some jurisdictions are now restricting the types of decorative water features which can be installed and operated at project sites. Using stormwater design strategies that can replace typical water feature installations provides another opportunity for decision makers to meet their goals of using less water while also providing a compelling space for users. Roofs can be designed to collect stormwater and discharge that water to mimic many popular fountain styles. Rain chains that control stormwater as it falls from the roof into a landscape are one such option. Custom scuppers can be designed to direct a portion of the roof’s stormwater into a fountain-like element at ground level before it enters the site’s drainage system.
On a recent project, many of these strategies were used and the display of stormwater became a major theme of the landscape design. A natural stream concept was developed with a water feature that collects a portion of the roof’s rainwater. This fountain-like feature dissipates the energy of the falling water and then releases it into a natural, cobble-lined stream bed that winds its way through the project site, eventually emptying into a detention pond that will integrate with the campus’ future plans to improve and control all site stormwater. Native and drought-tolerant plants that can accommodate intermittent inundation were included, and pathways and breakout areas contribute to a vibrant addition to the campus’ landscape.
Though not all projects are required to meet agency requirements concerning stormwater usage, a design with features to slow and improve the quality of run-off should be considered an important planning technique which can be integrated seamlessly with other Low Impact Development (LID) strategies. The human factor is another strong motivation for the development of outdoor spaces because using stormwater as a device to draw people out into the place is often considered a successful strategy for designers.
Most of the design feature improvements detailed above, and LID strategies in general, are more cost-effective than the conventional stormwater management practices such as extensive underground drainage systems, below-surface storage solutions, and mechanical treatment options. While all stormwater control solutions require maintenance, LID and other design strategies provide value above ground, where users can hear, touch, and see how the stormwater moves across a park, parking lot, streetscape, or residential development.
Travis Rice, RLA/LEED AP is a landscape architect at LPA Inc. He may be reached at firstname.lastname@example.org.