Kerr Lake Shoreline Stabilization

Client: North Carolina Division of Parks and Recreation

Location: Warren and Vance Counties, North Carolina

Services: Shoreline assessment, surveying, design, permitting, agency coordination, specification preparation, bid coordination, and construction management

One of the largest lakes in the Southeast, the John H. Kerr Reservoir is a tranquil haven for outdoor recreation. The 50,000-acre reservoir, constructed in the early 1950s, offers scenic views along more than 800 miles of wooded shoreline, straddling the Virginia-North Carolina State line.

In recent years, however, the natural face of the lakeshore began showing signs of heavy erosion. Stretches of shoreline crumbled, allowing lake water to encroach on adjacent infrastructure and recreational facilities. Hurricane Fran’s assault on the region in 1996 further eroded areas already degraded by the lake’s variable water levels, wave action, and occasional flooding, fed by waters from the Roanoke and Dan rivers.

A Proactive Solution—In 1998, the North Carolina Division of Parks and Recreation (NCDPR) initiated a three-year, $4 million program to restore the damaged shoreline. Working with NCDPR, KCI’s surveyors, scientists, and engineers developed structural, biotechnical and bioengineering design solutions for five miles of lakeshore in Vance and Warren counties, north of Henderson.

Site Analysis—The KCI project team evaluated conditions at 71 sites in seven recreational parks bordering Kerr Lake. Surveyors analyzed topographic profiles and conducted surface and underwater surveys to establish benchmarks. Geotechnical engineers tested and classified soils, determining shear strength, bearing capacity, and other characteristics. At each site, the team considered restoration factors, such as the severity of erosion, currents, and anticipated wave energies, as well as usage requirements, stabilization costs, expected levels of public acceptance, and safety requirements. Scientists also determined the tolerance and potential survivability of various on-site plant species to fluctuating water levels in developing the project’s bioengineering applications.

Stabilization Techniques—In recommending design solutions to NCDPR, KCI considered findings from the studies in relation to the severity of erosion at each site, the recreational uses of adjacent lands, and the cost of potential solutions. Each site offered unique challenges, requiring different design solutions. In some areas, KCI scientists applied bioengineering techniques, such as live cribwalls and brush mattresses, to stabilize the soils and slopes; but in other areas, where high wave energies did not allow for bioengineering solutions, KCI used structural techniques, such as segmental retaining walls and riprap. Scientists also incorporated a ‘hybrid’ approach, such as joint plantings, which combines the best of both worlds to enhance a site’s aesthetics and improve shoreline habitats.

Construction Management—NCDPR initiated the two-phase project in Spring 1999. During construction, KCI worked closely with the Division, obtaining review comments from the North Carolina State Construction Office, the U. S. Army Corps of Engineers, the North Carolina Division of Emergency Management, the North Carolina Division of Water Quality, and the Federal Emergency Management Agency. The project team scheduled the construction to accommodate recreational needs and the lake’s water levels, which vary by as much as 20 feet in a given year and a foot on any given day. The second phase was completed in Spring 2001, with 59 sites stabilized in seven recreational areas.

During construction, KCI assisted NCDPR with bidding, contract award, quality review, site inspection, change order, and final closeout services. Although initial construction cost estimates approached $4 million, KCI’s innovative structuring of plans and specifications minimized project costs, allowing NCDPR to complete the work for $2.8 million. Following the project, NCDPR rated KCI’s overall performance in the 93 percentile—one of the highest scores ever awarded to a consultant.

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