Blame it on the Rain: Changes Coming to Stormwater Regs

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Raleigh’s stormwater staff might find water runoff pretty interesting, but many city residents don’t think about where that water is headed until it floods the basement.

Managing stormwater runoff is vital to keeping Raleigh’s streams and creeks healthy because that water will eventually end up in someone’s water supply. If it’s not Raleigh’s, it could be Goldsboro or Smithfield’s supply.

While the suburban parts of the city have newer stormwater infrastructure, downtown Raleigh’s 100-year-old system needs to be replaced. Water quality regulations might mean more stormwater controls for existing development. The big question is, who’s going to pay for it?

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Ariella Monti

Stormwater flows from a gutter system along Hargett Street in downtown Raleigh.

Stormwater Management
Raleigh’s stormwater management program came about in 2001, a few years after the state issued the Neuse River rules intended to reduce the nitrogen levels in Neuse River basin. The rules set benchmarks for residential and commercial development so that any built area that has 14 percent or more impervious surface needs some kind of water treatment.

Impervious surfaces are areas water can’t penetrate, like driveways, parking lots or buildings.

Water flows off these surfaces sweeping everything on them, including dirt, sand, pet feces, car fluids and other pollutants. Those pollutants trickle into creeks and streams and finally, into the water supply.

The Environmental Protection Agency requires stormwater management to be done on site using best management practices or BMPs.

Types of BMPs
Wet Ponds – Wet ponds are large retention areas that will always be filled with water. These are often used on larger development sites.

Dry Ponds – Unlike a wet pond, a dry pond is dry until it is temporarily filled with water during a storm. The water is held there for two to four days before seeping into the ground.

Wetlands – Like a wet pond, wetlands hold water permanently, but include aquatic plants and grasses. Wetlands are hard to maintain and expensive to build, but they are effective because the plants suck up a lot of the nitrogen.

Rain Gardens – Sometimes known by their a less-pretty name, bio-retention areas, rain gardens include layers of mixed soils, mulch and vegetation. The theory is that as the water drains through the natural filter, many of the impurities are taken out and absorbed by the plants. They are fairly easy to maintain.

Sand Filters – While open-area sand filters are seen on the coast, these devices are often used underground, like under parking lots. Much like a coffee filter, the water flows into the device, which filters out the pollutants.

Ben Brown, the city’s stormwater development supervisor, said developers are responsible for installing and maintaining BMPs in new developments. In residential communities, homeowner associations make sure the device is running properly and issue annual inspection reports to the city.

Brown said that since 2001, about 1,500 BMPs have been installed within city limits.

Maintaining them would require a massive public workforce. Those BMPs are also on private property, for which the city may not have access, unlike a sewer or a water line.

Old Versus New
New developments are taken care of, but as more water quality regulations take effect, existing developments will have to meet stricter standards.

That might mean installing new BMPs, and no one is sure who will pay for those, said Raleigh Stormwater Utility Manager Danny Bowden.

Raleigh pays to maintain any BMPs it has already installed on private or public property, with the exception of projects funded by the city’s cost-share program.

The city invests $250,000 in the cost-share program, which reimburses property owners 50 to 80 percent of the cost of installing a stormwater device, such as rain barrels. Since 2009, the program has funded between 15 and 20 projects. Bowden expects that investment will soon increase.

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Jennifer Suarez / Raleigh Public Record

A jogger runs by the wetland at Fred Fletcher Park in Raleigh.

Aging Terracotta
In addition to questions about development upgrades, the city also faces another problem: old pipes.

During the past 20 years, concrete or corrugated metal has been used for stormwater drainage pipes, but many of the pipes placed in the early 20th century are made of terracotta. Most of these pipes are located downtown, where Raleigh first began.

“That stuff lasted a long time,” Brown said. “But it’s getting to the end of its useful life.”

Early Raleigh residents also didn’t give much thought to the eventual growth of the city, and many of the pipes are undersized.

Planning Commissioner Steven Schuster said the small, old pipes pose a problem as Raleigh focuses on dense growth downtown.

“We want our downtown to be more dense,” he said. “And at same time we have an infrastructure that doesn’t necessarily support that increased density.”

Because downtown Raleigh is a massive slab of impervious surface, stormwater runoff generates there more quickly than, say, in a suburban subdivision.

Upgrading downtown Raleigh’s drainage system would likely cost millions of dollars and require the approval of NC Department of Transportation, because many pipes rest under state-owned roads.

In some cases, such as Skyhouse, a new high-rise apartment downtown, the development’s construction will destroy the old pipes. Developer Edison Land is responsible for fixing those pipes.

Asked if this infrastructure replacement is a city problem or a developer problem, Brown said officials are leaning toward it being a city problem. But considering the high costs to upgrade the system, the development community might have to step in, too, he said.

For now, the city is mainly in reactive mode with the aging pipes, dealing with problems as they arise and tackling improvements as funding allows.

Schuster said the new Unified Development Ordinance (UDO) is forcing the city, property owners and developers to question how to pay for upgrading infrastructure.

The UDO will upgrade and replace the current zoning code.

The Raleigh Planning Commission just finished its review of the new code. City Councilors will begin review of the UDO next month.

Chapter 8 of the UDO requires adequate facilities, which include not only stormwater, but water, sewer and roadways. Site plans will only pass if developers can prove the public facilities meet the demand that would be created by the proposed development.

But if the existing infrastructure isn’t up to snuff, should the upgrade cost fall to the city or the developer?

City planners have recommended requiring the city to provide minimum standards and suggest developers take care of anything beyond that. How those minimum standards will be paid for is still a mystery.

Some developers may find it beneficial to install new pipes just beyond their development, but Schuster said it doesn’t do any good if they don’t keep going. Of course, private developers can’t be expected to pay for storm sewers for the whole city.

During a time of economic hardship, cities all over the country are trying to keep property taxes and utility fees low. Still, Schuster said the city needs to continue investing in downtown Raleigh or else.

“We’re going to start falling off those lists that we all want to be on,” he said.

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