The Greening of Stormwater Infrastructure

Every developer, resident and business must deal with water on their property. Several cities are working hard to bring their stormwater infrastructure into compliance with the federal Clean Water Act. In cities like Philadelphia, Chicago and Washington, D.C., that means a big push for alternative ways to capture rainwater, such as pervious pavements, rain barrels and greened streets, technologies that will be explained below in further detail. How does the “greening” of stormwater infrastructure affect REALTORS®? 

The answer depends on the neighborhood climate — meteorological, economic and cultural. Beverly Chandran is a Philadelphia REALTOR® with Coldwell Banker who started her career in the Maryland suburbs of Washington. She has the NAR Green Designation and has always been interested in environmentally friendly homes.

“In the Maryland market, people would say, ‘I want to see a green home,’” Chandran said, meaning one with environmentally sound and energy-saving measures built in. “In Philadelphia, only two families have said that in five years.” A big reason is cost. Homes with eco-friendly features tend to be more expensive. 

Water is a major issue in Grand Junction, Colo., where Linda Romer Todd is a REALTOR® with Associated Brokers and Consultants and has been a water activist for many years. Todd’s part of the state gets less than 10 inches of precipitation a year, so green stormwater infrastructure is not a selling point for homes.

But last year, the Grand Valley Drainage District imposed a stormwater management fee to fix deficiencies with the drainage district and bring the state into compliance with the Clean Water Act. Residential fees are as low as $36 for a house, Rodd said, but commercial properties with large paved lots — impervious surfaces that water can run off, sending pollutants to creeks and rivers — pay $15,000 to $20,000 a year. 

One way or another, REALTORS® are dealing with stormwater infrastructure, or will be soon. So it’s a good idea to be educated on the elements of green stormwater infrastructure (GSI). Here are some of the most important GSI measures cities have used, followed by examples of programs in Philadelphia and Prince George’s County, Md.

A more effective, cost-efficient alternative

Elements of GSI, include:

• Stormwater planters with trees collect rainwater and allow it to infiltrate the soil instead of running off pavement to pollute the waterways.
• Rain gardens are depressed areas planted with vegetation to collect rainwater. New York City’s Department of Environmental Protection has planted rain gardens throughout the city.
• Rain barrels, successfully used in Seattle and Lancaster, Pa., among other cities, store water that can be used by homeowners to water their gardens.
• Bioswales are small, planted areas in a sidewalk that collect rainwater. New York City has built thousands of them across its boroughs. But some residents have complained that the bioswales collect trash and are not properly maintained.
• Pervious pavements are a large type of green infrastructure that may not include greenery. They have small holes that let rainwater seep into the ground, replenishing the groundwater and improving water quality. On sidewalks, parking lots and other lowtraffic areas, pervious pavement can replace more commonly used impervious pavement of concrete and asphalt that creates runoff.

Philadelphia: 25-year plan for green infrastructure

Many years ago, Philadelphia built big tunnels underground to store the water from its snowmelt, so it would not go right into the sewage treatment plants. But rather than upgrade the tunnels and build new ones at a cost of billions of dollars, five years ago the city persuaded the U.S. Environmental Protection Agency that it could instead meet the Clean Water Act requirements by integrating green infrastructure throughout the city. The city is now five years into its 25-year Green City, Clean Waters plan. The plan is projected to cost $1.2 billion — calculated in 2009 dollars. The city is using all the measures listed above, plus others such as wetlands with native plants, green parking lots with vegetative buffers, and stormwater inlets leading to tree trenches — systems of trees connected by underground infiltration. 

To make the program successful, the city wanted to integrate green infrastructure into private properties, said Rouse — developments, businesses and parking lots. In most cases, the properties are being retrofitted with GSI.

“Managing stormwater is everyone’s problem,” said Marc Cammarata, deputy commissioner of planning and environmental services for Philadelphia Water. “We need to look at who is creating that hardscape and try to mitigate that and make it more naturalized.

“The regulations are not to squash development but to try to make things better,” Cammarata said.

To achieve its goals, the water department modified stormwater regulations for development. More stringent water management regulations kick in based on “earth disturbance.” If existing or new development modifies the earth on a site to a certain threshold, the developer must ensure that no more runoff occurs than before the development.

“Developers’ initial reaction was, ‘You can’t impose more regulations on development,’” said Cammarata. “People said, ‘Developers will leave the city.’” But developers want to be in the thriving urban center, and they have adapted.

“Now it’s part of the building community,” Cammarata said. “They know what to do — vegetated roofs, use of green space, energy enhancement — to make it more sustainable.” 

Although developers say the regulations have increased their cost, “when you factor it into new development, there’s ways to make your money back,” said Cammarata. “If you put a green roof in the building, you can rent or sell your property at higher cost.” 

A five-year report published in 2016 by Philadelphia Water estimates a 10-percent increase in property value in properties within a quarter mile of a GSI investment. Chandran, the Philadelphia REALTOR®, said the city’s green infrastructure initiative is more visible in Center City, which has seen a lot of new construction with the real estate boom.

“Increased property values associated with stormwater infrastructure can be seen easier in Center City, and these benefits will transfer to other communities later down the road,” she said.

Prince George’s County public-private partnership

For Prince George’s County, Md., to meet its compliance obligations under the Clean Water Act, the county formed an unusual type of public-private partnership with developer Corvias Solutions. This model has more control by the county and, at the county’s insistence, more emphasis on social goals such as workforce development. That type of partnership is emerging as a trend, said Paula Conolly, coordinator of the Green Infrastructure Leadership Exchange. 

Corvias, which has historically developed military and university housing, has a contract to design, build, finance, operate and maintain 4,000 acres of property to be retrofitted with green stormwater infrastructure, said managing director Greg Cannito. Corvias also handles community outreach and education. 

The work consists of 120 projects including public schools, churches and nonprofits. Corvias is installing rain barrels, permeable pavement and rain gardens, and removing impervious surfaces and planting more trees. 

“Developers don’t usually like green infrastructure,” said Cannito. “It’s more expensive on the construction side and less expensive on the maintenance side.” But because Corvias is doing so much GSI work, that is driving the cost down.

Cannito warns that if green infrastructure is put in the streets and it is not properly maintained, it can become an eyesore. In this case, Corvias has a 30-year maintenance contract for everything the company builds. That long-term maintenance plan helps maintain property values.

Conolly, who has a good overview as coordinator of the Green Infrastructure Leadership Exchange, said the data does not yet exist showing that green infrastructure is less expensive than traditional gray infrastructure. The up-front costs of green infrastructure are relatively reasonable compared with gray infrastructure (such as building a new sewage treatment plant), but long-term costs mount up and have no end date.

“The number of [GSI] installations is only going to increase,” Conolly said. “They need to be maintained on a very regular basis, or you get complaints.”

Communicating the value of green infrastructure to the public is not easy. GSI is much more visible than an underground sewage system, and any problems such as poor maintenance are immediately visible.

“Green infrastructure is a permanent change in people’s lives,” said Conolly. And that is never easy.