Stormwater management challenges inspire innovative and beautiful solutions

From lush rain gardens and underground wetlands to concrete assemblies modeled after the Roman catacombs, stormwater management systems have evolved to meet the design desires and physical constraints of today’s construction sites.

On commercial, multi-family, academic and other developments, Live Green Landscape Associates is turning stormwater management into design features through the creation of artfully landscaped and planted retention ponds.

At other developments, the high cost and limited availability of land has pushed project teams to include underground stormwater management systems instead of conventional surface ponds.

“The big benefit with these systems is you are not losing real estate. You can place parking lots, tennis courts and playing fields over these structures,” said Anthony Corteal Jr., Principal at MK Consulting Engineers.

That benefit convinced project teams to use underground systems at Furley Elementary/Middle School and the Hilton Recreation Center in Baltimore City. Some commercial developments, such as the Floor and Décor store currently under construction in Owings Mills, are using underground systems in order to maximize parking space.

“It’s not just urban projects that are using these systems,” Corteal said. “For some school sites in Baltimore County, it is hard to get enough real estate to put all the athletic programs and playing fields within the limited site area. These systems eliminate the need to put in massive stormwater management ponds and water quality structures above ground.”

“One of the main, innovative approaches that we have been using is the Rotondo StormPod,” said Ryan Pike, Senior Associate with MK. “It looks like a Roman arch system. The top has that classic arch and the bottom is a rectilinear base. And the pods are like Legos. They interconnect.”

Made from fiber-plastic-reinforced concrete, the pods are typically eight feet wide by 16 feet long and six to nine feet tall. The system provides a lot of stormwater storage capacity in a small space, Pike said. It can also include a sand-filtration system that rapidly cleans rainwater and runoff before it flows out to a stormwater drain.

On some projects, MK has also installed modular, linear wetland systems to manage and filter stormwater. Enclosed in a concrete vault that is buried onsite, the system funnels water through pre-treatment and treatment chambers before discharging it to a storm drain.

“It mimics a wetland,” Pike said. “Stormwater gets the full, biological, anerobic treatment that a typical, above-ground wetland would provide. But it accomplishes that in eight foot by 12 foot boxes. That is roughly a tenth of the size you would need for an above-ground system.”

On other projects, MK is using soil restoration to limit the use of both underground and surface-level stormwater facilities.

“Soil restoration is a method in which you churn up the soil and make it easier to infiltrate so that water percolates into the soil and goes to a suitable drain,” Corteal said. “You can’t use this method on an urban site where you are going to put a building. But you can use it on projects like the Somerset Redevelopment in East Baltimore. It will include a 1.3-acre park which will be mostly vegetation and lawn. That space will allow us to do soil restoration, increase infiltration and reduce the underground stormwater management structures.”

On sites with ample space, however, some clients are using micro bioretention ponds to both manage and treat stormwater and to create beautiful landscaping.

“Some have 20-foot trees installed and a million small, one-gallon plants and flowers so that Rudbeckia and Black-eyed Susans take over and make the pond look really pretty,” said Justin Jones, Commercial Production Manager at Live Green Landscape Associates. “Recently, some clients have been using seed mixes to try to get wild flowers to grow in the ponds. There’s also a big push to include native plants. They help projects get LEED credits.”

At Anne Arundel Community College (AACC), Live Green created an elaborate, eye-catching bioretention pond that stretched the entire length of the Health and Life Sciences building.

“There were probably 12,000 plants that went into that pond,” Jones said.

Edged by precast landscaping walls and tiered, the stormwater management facility “dropped down to a gravel river bed with some large boulders,” said Kevin Crawford, Project Manager. “The boulders were so large that we had to bring a crane onsite and set each boulder individually, exactly as it was marked on the design.”

The developer of an apartment complex in downtown Frederick, placed their stormwater management facility at the entrance to the community.

“They included their entrance sign, a water feature and a floral area so that it is a major accent as you enter the property,” Jones said.