More than 65% of the Largest Bass on the Texas Top 50 List have been caught from Wood County's Lake Fork reservoir. More bass over 8 lb (4 kg) are caught from Lake Fork than from any other lake in the state of Texas. In fact, the state record bass, weighing nearly 18 lb (8 kg), was caught there in 1992.

Even with a well-earned international reputation as a fisherman's mecca, the primary purpose of this man-made lake is to provide water for industrial and municipal use. The decades-long building project was funded through a water-supply agreement with Texas Utilities Generating Co. Inc. and, ultimately, will supply water to the cities of Dallas and Longview and several other smaller municipalities. To do that will require not only a mammoth conveyance and pumping system but also a heavy-duty electric supply.

The city of Dallas, Texas, began its preconstruction planning of the water-conveyance system by contacting Wood County Electric Cooperative Inc. (WCEC; Quitman, Texas, U.S.), the utility that would serve the large electric load. Until what became known as the Dallas Water Utilities Project came along, WCEC primarily served rural residential, light-commercial and oil-field customers. The Dallas Water Utilities Project was projected to be the largest single load for WCEC and would entail a complex construction project.

COMMUNICATIONS SUCCESS

Lake Fork, which is managed by the Sabine River Authority of Texas (SRA), is one of the region's most important attractions for tourism — an important economic driver for Wood County. Therefore, there has been substantial interest in the development of the water-conveyance system. Some local folks feared lower water levels would disturb the fishing action. So, there needed to be assurances the construction of the conveyance system and the enormous raw-water-pump station, along with the subsequent transmission lines for powering them, would not harm the ecosystem.

All transmission line installation projects in Texas must be evaluated for potential environmental impacts. WCEC hired the environmental team from engineering firm PBS&J (Dallas) to prepare an environmental impact report (EIR), which evaluated the potential for the project to affect the lake and environs, the likely degree of impact and recommended measures to reduce or eliminate any negative impacts.

The EIR was presented to the public for comment, while SRA ran a successful public-outreach campaign that helped concerned parties understand how Lake Fork would be protected during and following the construction. After a thorough vetting, the EIR was approved

DESIGN REAPS IMPROVEMENTS

The design for the system called for a 138-kV transmission line across Lake Fork and a new 30-MVA substation to feed the 240 million gal/day (908 million liter/day) water-pumping station. The new substation was important to the design. The massive pumps needed a reliable energy source to send Lake Fork water flowing through a 108-inch (2.7-m) pipeline on its way to a 95-mile (153-km) journey to the Dallas Eastside Treatment Plant.

At the time of design, WCEC substations on either side of the lake were radially supplied, so when a transmission connection failed, the outages were widespread. To enhance reliability for these loads, the radially supplied substations had to be connected with a substantial tie line. Although the improvement had been planned for many years, economics had not yet allowed for the tie. When the Dallas Water Project came along, WCEC was able to justify improving that part of the system by making the changes in tandem with the larger construction project.

PLANNING THE ROUTE

Before beginning the project, WCEC was aware the installation would not be routine. The utility knew it would have to install some transmission line support structures in the reservoir bottom. The most apparent challenges would be to install them in water as deep as 70 ft (21 m) and spanning 1 mile (1.6 km) across the lake with as few support structures as possible. Locating a suitable alignment, or route, across the lake was just as daunting.

Back in 1975, when Lake Fork reservoir was under construction, navigation channels were cut in native timber, leaving standing timber over much of the lake's 27,900 acres (11,291 hectares). It's this standing timber along with fertile water that makes Lake Fork an ideal habitat for bass fish. Submerged timber in Lake Fork also represents a hazard to boat traffic. Buoyed boat lanes provide access through the reservoir. Foundations for the supporting transmission structures had to be located outside the boat-lane alignment to avoid interfering with lake traffic.

During the process, WCEC hired PBS&J to assist Cornelius-Pierce Consulting Engineers (Fort Worth, Texas), which was designing the transmission line on land, with the geotechnical investigation and design engineering for the transmission line and support structures in the lake. DGA (Monroeville, Pennsylvania, U.S.) supported PBS&J in the design, which called for three galvanized-steel support structures across the lake, each 208 ft (63 m) above the lake floor, and one steel support structure on either shoreline. Each support structure would be separated from adjacent structures by a span of almost 1600 ft (488 m).

PBS&J performed a lake-bottom survey along the proposed alignment for the transmission line to establish the locations and elevations of support-structure foundation sites. After completing the survey, PBS&J performed a traditional geotechnical investigation to characterize the physical properties of the soils below the lake bottom to ensure the integrity of the construction design.

The design and construction teams paid special attention to the technique that would be used to install the piles into the lake bottom. Because the body of water was a valued fish habitat and a drinking water source, the method specified for installing the support structures would cause minimal disturbance of lake-bottom sediments, reducing the potential for impacting the water quality. WCEC secured the services of Texas Power Construction (Austin, Texas) to do the bulk of the transmission construction. To speed construction, a helicopter crew hung insulators with stringing blocks and attached the rope that would be used to pull the stringing cable into the sheaves.