Redirecting rainwater a statewide concern

Stormwater runoff floods neighborhoods and downtowns and can push pollutants such as sediments, waste, oil and pesticides into the environment. Coastal and inland cities alike must consider where to direct the water and how to treat it to keep the public and the economy healthy.

Coastal communities contend with the heightened concern of protecting a tourism-based economy that depends on visitors who flock to the beaches. But keeping the state’s coastal tourism industry unharmed by beach closures carries broad, statewide implications: South Carolina’s gross domestic product from coastal tourism was estimated to be $3.5 billion, supporting 81,000 jobs, according to a 2009 study by the University of South Carolina’s Moore School of Business.

State regulators help coastal cities ensure safe conditions for water recreation. The S.C. Department of Health and Environmental Control collects water samples at more than 120 locations along South Carolina’s beaches. Samples are taken twice a month from May 1 to October 1. Beaches in the Myrtle Beach area are sampled weekly. If high levels of bacteria are found, DHEC issues an advisory suggesting people not swim in that particular area.

Not surprisingly, swimming advisories can turn off tourists, causing some to change plans and avoid visiting an area.

DHEC can issue a short-term or temporary swimming advisory that typically lasts one to two days. Long-term swimming advisories are issued for beach water monitoring locations that have an increased possibility of high bacteria levels due to stormwater runoff, especially following rain events. The long-term advisories and signs typically are located where stormwater from pipes or "swashes" (small creeks) flows across the beach to the ocean, according to the department.

Deep-ocean pipes and beach swashes

The City of Myrtle Beach completed its latest deepwater ocean outfall last year. An outfall is pipe infrastructure that isn’t visible to beachgoers, because it’s all underground, stretching under the beach and under the ocean out to sea. The city’s next project is planned as soon as officials identify funding for it.

"It’s expensive to move rain around," said Mark Kruea, public information director for Myrtle Beach.

"The coast is flat, so we have to help Mother Nature move stormwater runoff in the direction we want, to encourage drainage and prevent flooding. Fortunately, we don’t have any heavy industry or point-source pollution, so it really is just rainfall that we need to address."

The City of Myrtle Beach extends outfall pipes under the beach and ocean./Myrtle Beach

 He said the city has spent upward of $50 million in the past 20 years on stormwater management.

"That money becomes an underground drainage system or a beautiful lake or pond," said Kruea. "Along the way, we’ve eliminated much neighborhood flooding in low-lying areas. Our ocean water quality was good before, but it’s even better now, thanks to the deepwater outfalls. Plus, the beach looks better without the drainage pipes on it."

Funding came from a variety of methods. Voters approved a stormwater referendum in the early 2000s. The city also created a stormwater utility fee, received grants, borrowed from the state’s low-interest revolving loan fund and financed other projects.

The City of North Myrtle Beach has similar considerations, investing in ocean outfalls that pipe stormwater out into the ocean, away from swimming spots.

The city plans to begin construction on a new ocean outfall in the fall of 2018, said spokesman Patrick Dowling. The original stormwater drainage pipes will be removed from the beach and multiple landward storm water pipes will be directed into one larger pipe that runs under the beach and about 1,200 feet out into the ocean before discharging stormwater. This will help to significantly reduce bacteria counts in the swimming zone, Dowling said.

Since 2002, North Myrtle Beach has funded and installed five ocean outfalls at a total cost of $26.7 million, primarily using revenue from a monthly stormwater fee. The state has contributed close to $6 million toward the projects.

After the new ocean outfall has been constructed, the city is planning six more ocean outfalls over the next several decades at a total estimated cost of $80 million in today’s dollars.

To date, through its ocean outfall construction program, the city has been able to remove 21 stormwater drainage pipes from the beach, while 29 pipes remain, according to Dowling.

Deep-ocean outfalls aren’t the only way to address stormwater on the coast.

In the Town of Surfside Beach, there are six discharge points along the beach that carry the water across the beach into the ocean.

"The majority of the discharge enters detention ponds in order to settle out pollutants before discharge," said John Adair, public works director for Surfside Beach. The discharge flows across the beach instead of being piped into the ocean.

Stormwater capital and operating costs are currently funded through a portion of the tax millage. But, said Adair, a utility fee is possible in the future as an alternative.

Working with developers

Because stormwater flows directly into waterways without being first sent to a treatment plant, it is essential to ensure that municipal, commercial and residential activities do not pollute the water, said Tanya Strickland, environmental coordinator for the City of North Augusta’s Stormwater Department.

To that end, developers looking to build in North Augusta are required to acquire a city-issued permit as well as a second permit from the state, the National Pollutant Discharge Elimination System General Permit for Construction. Sediment is one of the top pollutants of waters. Preventing sediment and other pollutants from leaving a construction site and affecting natural resources and waters within a community is critical for their protection, Strickland said. 

North Augusta also requires developers to build wet ponds with a treatment system component to them, such as wetland plants on the bottom. These ponds treat stormwater runoff through settling and biological activity.

In an additional effort to provide stormwater treatment and improve the ecosystem, North Augusta developed its Brick Pond Park, a 40-acre restored wetland and stormwater treatment system. Before the restoration began in 2006, the ponds were disconnected, with low to no oxygen, excessive nutrients, trash and industrial debris. 

North Augusta and the developer of an adjacent community worked together to create the park through a public/private partnership for the Hammonds Ferry Riverfront Development. 

The team acquired grants to develop the ponds, and the city built a new city municipal center adjacent to the ponds. The Hammonds Ferry development is on the other side. Strickland said the city and development are both using the ponds, which provide stormwater treatment, a public park and stormwater education center. Use of stormwater treatment systems are required by city and state permits for all construction sites that are larger than a certain size.

The ponds were connected by reducing or removing berms that were left years ago. Waterfalls with pumps were installed near the constructed wetland to provide movement and aeration. Plants were added to provide stormwater treatment allowing the removal of pollutants coming into the system with runoff from roadways, yards, parking lots and garden areas. 

Today, the wetlands within the park are healthy and provide habitat for a variety of wildlife. The park is used as a tool to educate the public – everyone from schoolchildren to college students to senior citizens – about stormwater and its impact on the environment, Strickland said.