Major Drainage and Water Quality Improvement Projects

Crabtree Swamp Rock Weir
Horry County Stormwater installed a low-head rock weir in Crabtree Swamp for the purpose of controlling channel and bank erosion. The project is permitted by the US Army Corps of Engineers and used a design prepared by the US Department of Agriculture's Natural Resources Conservation Service. If the project is a success, additional weirs will likely be installed. The upper reaches of Crabtree Swamp are experiencing significant bank and channel erosion. The weir is designed to slow the water down and collect sediment in an attempt to build up the channel bottom. The weir was placed just downstream from a small bridge in hopes of arresting the undercutting that was occurring there.



South Strand Recreation Center Floating Wetlands
Horry County Parks and Recreation needed a way to control algae fed by fertilizer at the new South Strand Recreation Center ballfields. Horry County Stormwater contracted Charleston Aquatic Nurseries to install floating wetlands to compete for nutrients with the algae. The Coastal Waccamaw Stormwater Education Consortium turned the event into a demonstration drop-in for HOAs and residents and provided an information booth. Floating wetlands are an alternative algae control method suited to neighborhood stormwater ponds.



Carolina Forest Recreation Center Constructed Wetland
Horry County Stormwater created a constructed stormwater wetland at Carolina Forest Recreation Center in spring 2012. Students and teachers from Ocean Bay Middle School Science Club helped by removing invasive cattails and planting native aquatic and wetland plants (selected planting photos courtesy of The Sun News). The Science Club plans to monitor the progress of the wetland and its effectiveness in removing pollutants from stormwater runoff and providing wildlife habitat for native animals. The activity was co-sponsored by the Coastal Waccamaw Stormwater Education Consortium. Since that time, the constructed wetland has been featured as a demonstration site in Low Impact Development workshops for professionals.



Administration Building Rain Garden Retrofit
In Fall 2010, Horry County Stormwater undertook a project to retrofit a failing dry detention pond at the main administration building in Conway. The pond had become a nuisance, with ponding in the bottom preventing proper maintenance and serving as a mosquito breeding ground. The failing pond became an opportunity to demonstrate a large-scale bioretention area, or rain garden. With the help of volunteers from Camellia Garden Club, the project was a success and serves as an example for low impact development techniques.



BiLo Regional Pond 
For years, the Caropines and Deerfield drainage basins in southeastern Horry County experienced flooding problems due to drainage capacity issues. In 2008, Horry County acquired the space to install a regional stormwater pond to handle the storm flow from these areas. The pond was expanded in 2009. The pond is equipped with a fine mesh screen that prevents litter and debris from passing through it into Lake Elizabeth in Surfside Beach. Furthermore, based on water quality testing, the pond has proven effective at removing nutrients and bacteria from the water, protecting the downstream recreational lakes and beaches. Click here to see a water quality testing report from before and after pond construction.




Carolina Lakes Weir Project




Ultraviolet Disinfection Project at Pirateland Campground
In 2009, Horry County Stormwater installed an ultraviolet light disinfection system at Pirateland Campground to treat bacteria-laden water in Blue Heron Pond before it discharges into the Atlantic Ocean. Site selection was driven by public safety concerns. Before and after water quality sampling was performed. The project has proven to be effective in treating water in Blue Heron Pond. Click here to see a report on the project.



Crabtree Swamp Watershed Floodplain Restoration
After almost a year in the making, in 2008, Horry County and the City of Conway signed a Memorandum of Understanding with the Horry Soil and Water Conservation District and Crabtree Swamp Watershed Conservation District to undertake an initiative to restore Crabtree Swamp to a more natural state. The swamp was channelized in the 1960s by the U.S. Army Corps of Engineers for agricultural drainage and again in the 1980s. Decades of maintenance led to a trapezoidal channel with failing banks and an eroding channel bottom. In 2009, the group with help from partner agencies (Coastal Carolina University, Clemson University, US Fish and Wildlife Service, USDA/NRCS, SC DHEC, and US EPA) completed the first phase of a floodplain restoration project. The project was designed to increase flood storage capacity, stabilize the banks, filter pollutants from water with native plantings, and provide wildlife habitat. Project monitoring and assessment is ongoing. The project was successful and a second phase is planned for 2012. For a project report, click here.

*New* - Horry County Stormwater receives inaugural US EPA Region 4 Rain Catcher Award

 



Azalea Ave parking Lot project

The Azalea Avenue Public Parking Lot, which was completed in May 2012, provides 49 new public parking spaces in a community with a high demand for parking (adjacent to the Garden City Business District and across the street from one of the more heavily used public beach access points in Horry County).    Due to the environmentally sensitive location of the new parking lot, permeable interlocking concrete pavers were used for all of the parking spaces.  These pavers allow storm runoff to be infiltrated through the stone and gravel base and into the uncompacted native sandy soil subgrade below.  This direct infiltration has the additional water-quality benefit of keeping pollutants in place in the underlying soil and pavement substructure rather than transporting them directly into the nearby environmentally sensitive salt water tidal marshland.