By Mark Darrough - August 25, 2019
The second in a two-part series examines a disconnect between developers and “green infrastructure” approaches that reduce stormwater runoff while bringing economic benefits to the table.
HAMPSTEAD — Many conservationists see development as an encroachment on the environment, while many developers see preservation efforts as an obstacle to economic growth.
It is often a polarized discussion between the two, especially when it comes to the issue of stormwater runoff into the waterways of the fast-growing areas outside Wilmington, like Hampstead and Castle Hayne.
But for North Carolina Coastal Federation’s Lauren Kolodij and longtime Wilmington developer Burrows Smith, there is a smarter way to build — one much more effective than conventional systems in reducing runoff while increasing the profitability of a development.
READ PART I: Stormwater runoff and development’s increasing impact on the coastal environments of Topsail and Stump Sound
“The most concerning thing is, we continue to develop additional systems that collect and convey stormwater runoff to either ponds — which are ineffective — or for the most part, into ditches then to the roads and straight into the waterways,” Kolodij said. “If we continue with that kind of development approach, we’re really shooting ourselves in the foot.”
In contrast, low-impact development (LID) practices mimic an area’s natural ability to handle rainwater while disconnecting the traditional conveyance system. Take gutter downspouts, for instance, which traditionally pour water from roofs onto driveways and into roads or stormwater drains. An LID approach redirects these downspouts into rain barrels, rain gardens, or onto lawns.
“You’re taking the stormwater and soaking it in before it has the chance to become polluted runoff,” Kolodij said.
She referenced a program the city of Portland implemented from 1993 to 2011. During this time the city disconnected more than 56,000 downspouts, which ultimately removed 1.3 billion gallons of stormwater from its combined sewer system annually, according to city estimates.
In 2014, N.C. State University published research that had focused on four residential downspout disconnection studies in Durham to examine whether directing rooftop water over lawns can substantially reduce runoff volumes. Analysis of data from the initial study period showed a 59- to 99-percent total volume reduction.
“We’re not saying, ‘Don’t develop.’ That’s not what it’s about. It’s about developing smarter,” Kolodij said.
Economic benefits of LID
For Smith, who has been building in the Wilmington area since 1982, environmental and economic benefits merge together when designing an LID system.
“There are buyers in this market who appreciate when a developer doesn’t clear cut everything and wipe it all out,” Smith said. “People really appreciate when you don’t wreck the environment, like most developments are doing.”
Smith is currently developing a 315-acre piece of land in Castle Hayne on the Northeast Cape Fear River, where he said lots range from $100,000 to $600,000 on the riverfront. Instead of building expensive stormwater retention ponds that take up valuable green space, he uses parks and infiltration basins — essentially bowl-shaped depressions in lawns — to collect runoff before it can go into the river.
Lots facing the park sell at premium prices, between 10 to 15 percent more than other lots, according to Smith. He said it costs $75 to mow the 2-acre park, whereas building a large retention pond would have cost $400,000 to $500,000 with much more expensive maintenance expenses.
A park at River Bluffs designed to hold water during major rain events then naturally filter the water to prevent flooding in the area. (Port City Daily photo/Courtesy River Bluffs)
In the first phase of constructing 100 homes, he estimated $2 million in savings by using an LID design versus a traditional stormwater management system.
Additionally, he said in a neighborhood where all the water goes into a retention pond that can only hold a certain amount of water, there is a limit on how large a house can be built.
“They’re always going to want to add a patio. People always want an add-on,” Smith said. “And that’s not an easy thing to tell a customer — that you can’t do something. You spend $500,000 on a house and a lot, and then you’re told you can’t build a patio.”
But for the owner of a 3,500-square-foot house at his River Bluffs development who wants to add an additional 1,500 square feet, Smith said as an example, that owner could install more underground pipes to the infiltration system to make it happen.
The disconnect
Kolodij said fast growth isn’t just isolated to Hampstead. Towns like Swansboro are “exploding with development,” as evidenced by the familiar signs of a Dollar Tree, Pizza Hut, and Walmart opening there in recent years. But although the state and county can encourage LID — and Pender County has taken that stance since 2011 — she said there is a “broken link” that exists between developers and the green infrastructure approach.
“I don’t know if it’s consumer demand or if developers are not catching on to this,” Kolodij said. “A lot of commercial developments are not planned locally. It’s a big company making those designs from faraway. Business-as-usual approaches are very hard to change.”
She is encouraged by one large company, Walmart, who met with the Coastal Federation before building one of its supercenters at Porters Neck. Although they built a retention pond, they decided to change their designs to include “landscape islands” and curb ramps that push water into those islands during an average rainfall.
This produces a double benefit, she said, by reducing the amount going into the pond or becoming polluted runoff while also soaking in that runoff incrementally into the landscape islands that need the water for irrigation. And that’s the key to the LID approach — using rainfall as a resource while preventing runoff.
“I would think and hope that that approach would become more appealing to communities and developers and local governments as they’re dealing with flooding and water quality issues,” Kolodij said.
She said local governments and communities are mainly concerned with the flooding aspect of stormwater runoff, which is “a real hazard and very problematic for local governments.” But while they can encourage LID, state and local governments cannot force it as the law stands today. Additionally, she said the state, who issues stormwater permits, lacks the resources to effectively monitor and inspect whether conventional stormwater systems are working or not.
Meanwhile, Pender County Planning Director Kyle Breuer said the county has actively promoted LID practices since 2011 when it published a white paper that provided the groundwork and education to implement voluntary provisions that could later be adopted as part of the county’s code.
“Once we were able to present our findings, we did an audit of our development code to identify barriers to implementing LID which resulted in a text amendment to our code to try and make it more palatable for developers to choose this option as opposed to traditional stormwater treatment best management practices,” Breuer said.
The amendment to the code, adopted in 2011, reduced the amount of parking spaces allowable for commercial businesses and also provided incentives for any project that met certain criteria deemed an LID. Projects that met that criteria would be allowed flexibility in certain dimensional requirements.
Kolodij said the state also gives incentives for using permeable pavement materials for disconnecting impervious surfaces, but ultimately, most developers choose the traditional stormwater model.
“We’ve had conversations with contracted engineers about the ‘broken link’. Even if a developer brings us their concept design, once they’ve spent any kind of money, they usually don’t want to go back,” Kolodij said. “It’s a big shock that Walmart actually did that with us, [it was] really a welcome surprise.”
She said Burrows had to go up against an initial pushback from New Hanover County when seeking approval for the River Bluffs’ LID system. But she hopes he will be able to set an example, along with commercial developments like Walmart, to bring more attention to the LID approach and that it becomes more appealing to communities, developers, and local governments dealing with flooding and water quality issues.
With the question of how much impervious surface someone is allowed to build, an issue that Kolodij said has produced polarized conversations during her years working on stormwater runoff — between developers and the state, between developers and the community — she hopes there is more exposure to LID’s economic and environmental benefits.
“I think what we found with LID, and with Burrows Smith, is that you can have both,” Kolodij said.
[Read the story as published here.]