SubscribeLocated in Cameron Parish in the southwest corner of Louisiana, the Sabine National Wildlife Refuge is the largest coastal marsh refuge on the Gulf. Established in 1937, it occupies the marshes between Calcasieu and Sabine lakes.
The refuge consists of a basin of wetlands between the Gulf's oak ridges and the coastal prairie, which is one of the most productive and fertile areas of North America.
Refuge waters consist of a freshwater impoundment of approximately 26,000 acres as well as marshes and canals totalling about 99,000 acres. Encompassing 124,511 acres of fresh, intermediate and brackish marshes, it is one of the largest estuarine-dependent marine species nurseries in southwest Louisiana.
There are over 115 miles of canals, 61 miles of levees, and 8 water control structures that are part of its complex water management operation.
At the Sabine National Wildlife Refuge, non-commercial crabbing and shrimping are permitted in the canals, which are open to boaters from March 15 to October 15. In late August and early September, cast netters can catch five gallons of brown and white shrimp in one hour.
Over 280,000 people visit the refuge annually. The exhibits in the refuge visitor center and the Westland Walkway are considered two of the main tourist attractions in southwest Louisiana.
Unfortunately, because of many man-made and natural factors, habitat losses have occurred on an estimated 40,000 acres of the refuge.
Major efforts have been taken to restore marsh habitat and to prevent further damage and this is where Rotork came in.
One of the refuge's biggest challenges was the restoration of habitat for maintaining aquatic conditions for saltwater and freshwater fisheries. There was a major disruption in the shrimp population due to the mixing of the salt and fresh waters. The plan was to build a water control structure to prevent salinity intrusion.
The U.S. Army Corps of Engineers worked in conjunction with Louisiana State University on the project, which was authorized to replace the water control structures on three major canals that allow water to flow from saline areas into the interior marshes. This would allow State and Federal refuge personnel to manage the salinity and water levels that influence the marsh vegetative community.
These new Rotork automated structures are designed to effectively discharge excess water, increase cross sectional area for movement of estuarine species, and help curtail saltwater intrusion into the marshes. On the three canals involved, there are a series of gate valves that are installed in pairs with one in front of the other. Each gate valve is fitted with an IQ actuator (see photo).
Each water control structure has a cabinet fitted with a IIS master station programmed with Sequence Configuration Tool (SCT) software and General Purpose Field Control Units. The cabinets are connected to a constant power source keeping the IIS master stations ready at all times. The operator pushes a button that powers up all of the actuators.
The operator can then adjust the elevation of the gates locally, based on the test results of the samples that are regularly obtained from the marshes.
On the last day of each month, the operator runs the actuators through a maintenance sequence. This sequence automatically runs each gate through a full cycle, one gate at a time, to ensure proper function.
Rotork is proud to have worked on this important project, which is making a vital contribution to maintaining a valuable and sensitive ecological habitat.