Louisiana's Cameron-Creole Project: An Ecosystem-Based Watershed Project

The Cameron-Creole Watershed Project comprises approximately 113,000 acres in Cameron Parish, Louisiana. The area is bounded by the Gulf Intercoastal Waterway on the north, Calcasieu Lake and Calcasieu Pass on the west, Louisiana Highway 27, Little Chenier Ridge, and Little Chenier Canal on the east, and the Gulf of Mexico and Mermentau River on the south. Because of severe saltwater intrusion, marshlands in the area were converting to open water as the saltwater killed the vegetation that stabilized the marsh soils. To counter this conversion, the Cameron-Creole Project was initiated. Sponsors of this cooperative project are the Gulf Coast Soil and Water Conservation District, Cameron Parish Police Jury, and Cameron Parish Gravity Drainage Districts Numbers 3 and 4.

The first phase of the project required construction of a 19-mile levee along the eroding shoreline of Calcasieu Lake. Because of its large size and diversity of uses and user groups, the project area was evaluated using an ecosystem-based approach. The input of various federal and state agencies along with local groups and individuals was encouraged in order to determine possible project effects. The suggestions received resulted in innovative approached to structural designs to allow water ingress and egress while achieving restoration and protection of marshland resources.

A two-year study involving paired ponds within the watershed was conducted to examine marine organism movement. The first year one pond incorporated weirs with boards set below marsh level and another pond had weir boards removed. The following year these weir conditions were reversed. Traps were placed at various heights on the vertical column to capture organisms entering or leaving the ponds.

The study results led to adjustments in design of structures in the Cameron-Creole Project, allowing for improved marine organism access. The major structure at Grand Bayou is designed to also allow access by fishermen by incorporation of a boat bay, along with four gated bays set below marsh level. The structures at Lambert and Peconi Bayous are four gated bays set below water level with vertical slots to allow ingress/egress of marine organisms. The structures at Mangrove and Noname Bayous are four bays set on fixed-crest weirs with one weir on each structure having vertical slots for marine organism movement.

It is necessary that water control structures be operated to maximize marine organism access while ensuring the protection and restoration of the marshland resource base. Input on developing operational plans for these structures was provided by both federal and state agencies, including the National Marine Fisheries Service, United States (US) Fish and Wildlife Service, Louisiana Department of Natural Resources, and Louisiana Department of Wildlife and Fisheries. Since the project area largely comprises the Cameron Prairie National Wildlife Refuge, the US Fish and Wildlife Service is responsible for operation of the structures so as to maintain salinities along two isohaline lines (5 ppt and 12 ppt), while allowing maximum marine organism ingress and egress.

In addition to the main structures, five culverts and four stoplog structures were installed on the eastern edge of the project, and eight flapgate culverts were installed on the Intercoastal Waterway on the north. These structures allow additional freshwater inflow to offset salinity from saltwater intrusion.

Natural Resources Conservation Service (NRCS) is monitoring changes in the vegetation communities of the project area to determine the effectiveness of the structures and their operation. Preliminary vegetation data and soil mapping data were collected in 1972, with monitoring being conducted at five-year intervals beginning in 1983. In addition, salinity and water depths above and below marsh levels are recorded. Changes in the land-to-water ratio over four time periods in different vegetation categories have been determined from digitized aerial photography.

Infrared aerial photography indicates dramatic improvement in the fresher marsh reaches. The area adjacent to the Gibbstown Bridge (Figure 1) has experienced rapid growth of aquatic vegetation between 1990 and 1993. Blind Lake (Figure 2) has been virtually covered with aquatics, and the pond edges and trenaisses are experiencing expansion of emergent vegetation.

Figure 1. Infrared aerial photograph of the area adjacent to Gibbstown Bridge in 1990 and 1993.

Figure 2. Infrared aerial photograph of the Blind Lake area in 1990 and 1993.