Elevating Stormwater Management


There has been a generational shift in the way our communities perceive, understand, and value the benefits of stormwater management. Gone are the days when the only mention of stormwater were decals on curb storm inlets. Gone too is the idea that low impact development measures are merely an option. As major storm events occur with greater frequency, often with infrastructure damage, people can see for themselves the ripple effects created by inadequate environmental measures and thoughtless development.

“Optional” to “Required”

During my two decades as a landscape architect, I have seen growth in the public’s understanding and appreciation of sustainable development practices. As jurisdictions increase requirements, developers continue to evaluate the cost-benefit of stormwater management measures such as bio-retention facilities, rain gardens, green roofs, and retention/detention ponds, to name a few.

stormwater management
(Photo: LandDesign)


These measures: reduce runoff, slow rainwater to mitigate erosion, and filter contaminants. And, while a civil engineer typically designs stormwater systems, the job of those in landscape is becoming more robust than ever before.

The basic idea of balancing hardscape with the right amount of landscape maximizes usage, value, flexibility, and performance. Not only are these projects some of the most cost effective, they can bring additional value. The recognition that landscape design can change the positioning of otherwise utilitarian stormwater functions opens up possibilities. Stormwater management becomes an opportunity for enhancement, rather than a byproduct of construction.

With appealing plant palettes and layouts that enhance the pedestrian experience, stormwater elements can often do double or triple duty. Incorporating stormwater management into a project’s “placemaking” strategy, where the “story” of a place is conveyed in design and function, adds value and increases awareness of ecological systems. Whether it’s green roofs or rain gardens, bioretention strategies don’t have to be hidden from the public, and instead can draw them in.

Case Studies

From Stormwater Pond to Waterfront Enticement. One of my firm’s recent projects involved the repositioning of RIO Washingtonian in Gaithersburg, MD, a retail center built in the late ‘90s with one of the largest stormwater ponds in the region. Rather than consider the retention basin just an infrastructure necessity tucked away behind the development, we turned it around by instead envisioning the pond as the soul of the project. With this simple idea, a new “brand” was created. Creating a “waterfront” experience attracted new retailers and restaurateurs, whose entrances and outdoor dining areas now face the water. Extending the boardwalk, adding seating, and including family spaces at the water’s edge transformed the project.

Runoff to Teaching Resource. The playground at Simon Elementary School, in Washington, DC, was once an uninspiring two acres of pavement with two small pieces of play equipment. Located less than 500’ from Oxon Run, a Potomac River tributary, the site was also a textbook example of paved land contributing to rainwater runoff issues. As part of an initiative to rehabilitate local rivers, the renovation served as a pilot to test integration of pending stormwater management regulations, while the being a vehicle of change for the school.

stormwater management
Simon Elementary School in Washington, DC, increased pervious surface by 30%, including rain gardens and bioswales, to help rehabilitate local rivers and enhance play areas. (Photo: LandDesign)

Working closely with school staff, parents, the District Department of the Environment, and the Department of General Services, my firm, LandDesign, developed a plan that marries play and sustainability. The design: reduces pavement; introduces rain gardens and bioswales: and incorporates play features including a basketball court and climbing mounds. Roof drains redirected to the bioswales weave through the play space, and large rain gardens surround the schoolyard, improving water management while providing a learning experience. Overall, a 30% increase in pervious surface slowed down runoff and reduced erosion. In 2018, this project was awarded the Potomac Chapter ASLA Social Impact Award.

Achieving “Net Zero” Water Use. Covering 27 acres and 450,000 square feet of office space, the new LPL Financial headquarters in Fort Mill, SC was designed to reflect the company’s commitment to employee well-being as well as environmental sustainability. Certified LEED Gold, the campus incorporates a 20,000 gallon cistern and three-acre wet pond which collects 18 million gallons of rainwater annually, exceeding the campus’ irrigation needs, eliminating the need for potable water, and making it a “net-zero” water user. Stormwater is diverted into facilities for infiltration, retention, and detention. Roof drains direct rainwater from the building and parking garage into the cistern, with excess flowing into a dry creek bed and rain garden. The wet pond, which doubles as an amenity, is fed by sheet flow. Drought tolerant plantings and permeable pavers add to sustainability. Within this natural setting are employee amenities—two miles of trails, outdoor meeting spaces, community gardens, and outdoor sport courts. Awarded “Project of the Year” from the Charlotte Business Journal, the project marries stormwater management with inspiring employee features.

Project Maintenance

While landscape architects work with property owners on design, it’s ultimately the landscape maintenance measures that ensure longevity and endurance. To be successful, the design must consider this.

Occasionally, we’re asked to assist in creating a landscape maintenance manual, outlining standards of care—from hardscape cleaning to weed control methods. We’ve found this is a useful tool in ensuring the vision remains. When landscape architects, owners, and contractors are on the same page, long-term results are palpable.

stormwater management
Practicing what they preach, LandDesign created a green roof at its award winning DC office that reduces energy costs, absorbs stormwater, and produces vegetables, herbs, and honey. (Photo: LandDesign)

Small Scale Strategies

But what about large residential properties or existing buildings that find they have drainage issues? Rather than directing stormwater to one big retention pond, smaller projects often use several rain gardens, bioswales, and micro-bioretention areas, scattered throughout the site—especially in urban areas. Many of our urban projects actually use bioretention tree pits along the streetscape. These can be retrofitted on existing projects or implemented on new developments. Drought tolerant native plants are also being embraced in stormwater solutions. All these elements are very common, low-cost, aesthetically appealing solutions to rainwater runoff issues. They are designed to filter stormwater runoff and improve water quality, but also double as landscape features.

Best management practices are always evolving and it’s imperative that landscape contractors make it a priority to stay informed. Projects where public awareness, resilient design, strong placemaking, and a sound long-term maintenance program intersect are the most successful in creating value. Most importantly, these projects create enduring places for people to enjoy that are not only beautiful and informative, but also perform.

Cañamar Clark, PLA, is a partner and landscape architect at LandDesign, a collaborative group of landscape architects and engineers seeking to build value in places they create. With a background in architecture, Cañamar Clark approaches projects comprehensively with the goal to transform the public realm into a legible, safe, and engaging environment. She works with design teams and municipal staff to convey a sense of place through underlying details that make big ideas work.

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