Kings Bluff Parallel Raw Water Main Pipeline

Water Transmission

Kings Bluff Parallel Raw Water Main Pipe ready for install

Pipe Specifications:

73,464 feet of 54” and 1,204 feet of 25” to 48” of Class 150 AWWA C200 spiralweld steel pipe with cement mortar lining and polyurethane coating. Pipe supplied in 50’ lengths with lap-welded joints for single inside field weld after backfill is completed.



Engineer Firm:

McKim & Creed Engineers


Garney Construction


Lower Cape Fear Water & Sewer Authority

To secure a reliable source of raw water for the growing region of Southeastern North Carolina, Northwest Pipe is manufacturing 14 miles of 54-inch cement mortar lined and polyurethane coated engineered steel pipe for a new raw water main traversing three counties served by the Kings Bluff Raw Water Facilities. In development for over ten years, the project is constructing one of the longest and largest water transmission mains in the region. The pipeline will transfer raw water from the Kings Bluff Raw Water Pump Station along the Cape Fear River in Bladen County to the Lower Cape Fear Water and Sewer Authority’s three-million-gallon storage tank located near the City of Northwest in Brunswick County. The main adds to a larger raw water system feeding the Sweeney Water Treatment Plant in New Hanover County, and serves the City of Wilmington and the entire Southeastern coastline of the state.

The new line parallels an existing 48” PCCP line constructed in the 1980s and is being built to meet the growing coastal region’s demand for raw water. The project includes three tie-ins between the existing 48” and new 54” lines. This requires pinpointing the exact locations of the existing pipe, joints, and valves to ensure the new steel pipe is precisely fabricated to flawlessly interconnect and minimize shut downs of non-redundant PCCP line.

To ensure timely delivery of product to the project site, we maximized freight by manufacturing pipe stands capable of safely transporting two sections of pipe per load. This load plan allowed the contractor to unload using a loader with padded forks in lieu of backhoe or crane, which was the optimal equipment solution for the coastal terrain.

The Right of Way (ROW) allotted for this project is the same as the existing line, so working around the PCCP already in place made for a limited ROW for installation. Despite the challenge, Garney Construction resourcefully coordinated the condensed space to accommodate haul road, pipe lay down, backhoe spoil pile, and bedding stone. Most trenches consisted of sandy material that was reused for backfill, while others were very wet and required water control measures.

At one point in its 14-mile path, an aerial 200’ stretch of the steel pipeline will cross above Livingston Creek as an exposed pipe bridge. Once complete, the new line will use nearly 5,000 tons of steel pipe capable of delivering up to 96 million gallons of water per day. Manufacturing is scheduled to wrap in Summer 2021, with the new pipeline fully operational by August 2022.

Ensuring this timeline requires strong working relationships amongst all project stakeholders supported by streamlined logistics every step of the way. On working with Northwest Pipe Company to successfully achieve the goals of this project, the project manager at Garney Construction says:

 “Garney is proud to be working in partnership with Cape Fear Public Utility Authority and Northwest Pipe on one of the area’s largest water transmission mains. We look forward to successfully delivering this project on time and on budget to do our part in helping secure Southeastern North Carolina’s water future, in addition to strengthening long-term working relationships with the surrounding communities and Northwest Pipe.”
CJ Cahoy, Project Manager
Garney Construction