C-1 Lake Hartwell Fish Habitat Enhancement

Project Description, Justification and Need
A second goal of the compensatory restoration plan for recreational fishing is to enhance the recreational fishery on-site on Lake Hartwell. Enhancing fish habitat in Lake Hartwell will in turn enhance the recreational fishery, which will help mitigate the estimated $18 million in lost services due to PCB contamination.

Lake Hartwell was constructed during the period 1955-1963. Lake Hartwell was created by construction of Hartwell Dam located on the Savannah River seven miles below the point at which the Tugaloo and Seneca Rivers join to form the Savannah. Extending 49 miles up the Tugaloo and 45 miles up the Seneca at normal pool elevation, Lake Hartwell comprises nearly 56,000 acres of water with a shoreline of 962 miles.

The vast majority of shoreline habitat in Lake Hartwell was cleared of vegetation during the Lake’s construction. This clearing activity resulted in greatly reduced littoral fish habitat complexity. Most of the littoral zone of Lake Hartwell is devoid of submersed and emergent aquatic vegetation, which provides important nursery habitat for sportfish and other aquatic species. Years of unabated shoreline erosion has also exposed expanses of clay banks, and increased sediment in the system. Bottom substrate is dominated by hardened clay and sand, neither of which provides optimum spawning substrate for sportfish species. The lack of available gravel substrate in particular is likely a major spawning habitat deficiency in Hartwell. Woody debris (trees and logs) is also very important in providing both littoral and deep-water habitat.

Large woody debris provides essential fish habitat because it provides protection from predators, spawning habitat, media on which invertebrates live and fish will feed, and fish concentration areas for prey species, which improve predator (sportfish) success. Some standing timber was left in the depths of Lake Hartwell, near the forebay during construction. However, woody debris is very sparse across most of the lake. The clearing and grubbing of the lake bed, natural aging of the lake over 50 years, and very active shoreline development have all served to greatly reduce woody debris in Lake Hartwell. We believe focusing habitat enhancement efforts toward correcting these deficiencies will improve the Lake Hartwell fish populations and the recreational fishery. Habitat enhancement areas will also serve to concentrate fish, which will improve the success rates and overall angling experience for Hartwell anglers.

Project Objective
Enhance the Lake Hartwell recreational fishery and angling experience through large-scale restoration of habitat focusing on improving habitat features.

Approach
The project purpose is to establish a large-scale fish habitat restoration program on Lake Hartwell. The project is projected to be implemented for 10 years.

The project will use a variety of materials and techniques to enhance fish habitat and recreational angling opportunities. Materials to be utilized may include root wads (stumps), brush, other woody debris, stone, gravel and a variety of aquatic and semi-aquatic vegetation. Appropriate materials will be utilized to construct both deep and shallow water structure to serve as cover habitats, nursery habitats and spawning habitats. Additionally, appropriate materials will be utilized and placed to provide armament and wave attenuation in erosion prone areas (ex. exposed islands).

High velocity and turbulence along the shoreline, specifically near islands, renders these areas inaccessible to fish. The placement of root wads and/or stone will act as “wave breaks” to create protected areas that will serve as spawning or nursery habitat for fish. Decreased wave action will also encourage shoreline vegetation, which will further develop the habitat complexity. Erosion associated with the high velocity areas has decreased the size of islands as well as increased sediment released into the system. The reduction of wave action will also act to preserve the islands and the subsequent vegetation growth will also enhance shoreline stability.

Large root wads will be placed at sites. The root wads will be anchored to weights and sunk using a barge that has a hydraulic deck to lift and slide the objects into the desired location (Figure 1). The root wads will be placed in moderately deep water (10 to 20 feet deep), in shallow water (5 to 10 feet) and in near-shore waters (2-3 feet deep). Another method of adding large woody debris may include dropping and cabling trees into the lake. This would be a technique most likely to be used adjacent to public lands such as Clemson Forest and Corps lands in non-developed, environmental areas. In appropriate areas stone and/or gravel may be used in concert with woody debry to enhance habitat and provide spawning substrate. A variety of native aquatic and semi-aquatic plants will be employed to enhance habitat diversity. Plantings will primarily be targeted in near-shore waters and shallow water applications to provide spawning and nursery habitat as well as stabilizing eroding areas.

The first year of the project will primarily be spent in planning and mobilization. Mobilization willl include but not be limited to project staffing, equipment acquisition and identification of potential staging areas. Efforts will be initiated to indentify and prioritize areas which can effectively be enhanced. Years 2 through 10 activities will include implementation of enhancement measures and the continuation of site selection and planning for subsequent years enhancement efforts.

Expected Benefits
Habitat enhancement will provide complex structure that will improve the fish populations by increasing the population density, size structure, reproductive success and survival. The materials employeed will function as habitat for numerous functions such as spawning and nesting during reproductive activities, nursery and refuge habitat for larval and immature fish, and foraging and ambush cover to improve feeding efficiency of popular predatory gamefish. The areas created should also serve as fish concentration areas which can be targeted by anglers seeking a variety of species. Also, shoreline stabilization should help reduce the rate of erosin that is occurring in some areas of the reservoirs. The ultimate result will include improvement in the Lake Hartwell recreational fishery, which will help mitigate the damage caused by PCB contamination. Figure 1. Fish habitat barge with dump bed used to enhance fish habitat (photo courtesy of Arkansas Game and Fish Commission)

Fish Habitat Enhancement Budget
The projected start-up budget for the Hartwell Habitat Enhancement Project is estimated at $658,000. This includes purchase of all equipment necessary to conduct enhancement efforts. This also includes personnel and all operation and maintenance to conduct the habitat enhancement work.

An annual operations budget after the initial start-up is projected at $230,000. The overall objective is to conduct this habitat enhancement project over a period of 10 years.

Follow this link to the Full Proposal http://www.dnr.sc.gov/news/pdf/OmnibusRecFishPlan10909.pdf

PLEASE NOTE - Comments posted here WILL NOT be passed on to the Trustees.

For further information on the RCDP contact:
Paul League, SCDNR, P.O. Box 167, Columbia, SC. Interested parties may also email Mr. League at Leaguep@dnr.sc.gov