Aransas project is a winner

Galveston District receives honors award in Design and Environmental Awards competition

Galveston District is the recipient of an honor award in the Chief of Engineers Design and Environmental Awards Program for the work being accomplished to save the habitat of the rare and endangered whooping crane. The team of Galveston District employees involved also received an honorable mention for the Design Team of the Year. Galveston's entry competed in a field of 59 projects.

The Aransas project is saving the endangered Whooping Crane from extinction by

protecting and improving its habitat while providing efficient navigation with state-of-the-art technology that works hand-in-hand with nature.

The project reach is a 31-mile stretch of the Gulf Intracoastal Waterway on the Texas gulf coast about 35 miles northeast of Corpus Christi in Aransas and Calhoun Counties. The area is the critical habitat of the rare and endangered Whooping Crane and includes about 13.25 miles within the Aransas National Wildlife Refuge.

Map of the critical habitat boundary for the Whooping Crane.

The project addresses the serious bank erosion problem at the Aransas National Wildlife Refuge, the wintering grounds for the rare and endangered Whooping Crane. Whooping Crane losses of about 2 acres per year are caused by vessel traffic and wind generated waves. The critical habitat loss adversely impacts the Whooping Crane, which is re-establishing itself after near extinction in the 1940's. The importance of the GIWW to the economy of the lower Texas coast and its uninterrupted usage is also critical. Tonnage transported along this section of the GIWW totaled nearly 27 million tons in 1995.

The project provides erosion protection and limited spill containment for the existing alignment of the GIWW while also providing marsh creation with the beneficial uses of dredged material. It required the formation of a remarkable and innovative team of State and Federal agencies to fully evaluate impacts to the natural resources as well as the Whooping Crane. This Interagency Coordination Team (ICT) was comprised of the Texas Department of Transportation, the US Fish and Wildlife Service, the Aransas National Wildlife Refuge, the US Coast Guard, the Texas Water Development Board, the Texas General Land Office, the Texas Parks and Wildlife Department, the National Marine Fisheries Service, the Environmental Protection Agency, and the Corps of Engineers.

Construction was limited in various ways. The entire projecthad to be constructed within three years. More importantly, no construction could occur while the Whooping Cranes were in the area, so the windows for construction were from 15 April to 15 October each year. Construction had to be tailored to fit not only the time but also the funding constraints and the site priorities set by the refuge personnel.

The project cost is $17,900,000 (current inflated estimate with contingencies--01 Oct 99 prices). The project baseline estimate was $20,313,000.

The project is a culmination of many outstanding, innovating ideas and designs. Erosion protection on the shoreline absolutely needed to be compatible with the Whooping Crane and its need to feed at the water's edge. Articulated concrete mats were flexible to mold to the existing shoreline, and the open spaces in the blocks allowed for vegetative growth throughout. This feature protected over 73,000 feet of shoreline.

Geotextile tubes are an ingenious concept that was refined and improved for use as a breakwater. This allowed seagrasses near the shoreline to remain intact while providing erosion protection for vulnerable areas. A breakwater fashioned of the tubes provided for 1,500 feet of shoreline protection.

Geotextile tubes are placed to form a breakwater in the shallow bay.

Spill containment was improved by the provision of booms that would be deployed by Coast Guard personnel. The Dredged Material Management Plan utilized the input and design of the Waterway Experiment Station (WES), the project team, and the ICT to plan for 1,600 acres of marsh..The Whooping Crane habitat will not only stop disappearing, it will also increase by at least 1,600 acres of prime habitat. The goal for the plan is to, "Use dredged material to create marsh similar to nearby natural marshes, including both high and low marsh, without adversely impacting natural habitats or navigation requirements".