Location and pond design are the most important physical factors for successful crawfish production. Proper pond construction gives the crawfish farmer better control over flooding, drainage, forage management, water circulation and harvesting. Although management practices can be easily changed from year to year, trying to change ponds that were improperly constructed can be expensive. Seek advice from your parish Extension Service agent and the Natural Resources Conservation Service engineer in your area.
Crawfish ponds should be located in flat, open areas, and the soils should have sufficient amounts of clay. Clay loams, sandy clay loam and silty clay loams are satisfactory soil types. A clay soil is necessary to hold water and to maintain the integrity of crawfish burrows because crawfish will die in burrows that collapse because of sandy soils. Generally, soils that can be rolled into a ball have enough clay for crawfish culture.
Perimeter levees should have a core trench cleared of debris to prevent water seepage. The minimum perimeter levee base should be 9 feet wide to prevent leakage from the burrowing activities of the crawfish. A levee system 3 feet high is adequate to contain the 8 to 12 inches of water necessary to cultivate crawfish. The land should have no more than a 6-inch fall between perimeter levees.
Otherwise, the area should be levelled or divided into two or more ponds. Ponds with a steep elevation difference restrict water management techniques and reduce harvesting efficiency. Interior ditches reduce circulation, and areas away from the channel may be low in dissolved oxygen. This reduces the effective production area of the pond. Interior ditches are difficult to drain, and they may serve as a refuge for predatory fish after ponds are drained.
Interior or baffle levees are constructed to guide water through the pond for proper aeration and to help maintain proper water quality.Baffle levees are built about 6 feet wide at the base. They should extend a minimum of 6 inches above the expected water level for the pond. If the part of the baffle levees above the water line is not substantial enough, settling and erosion will cause the levees to breach in one or two years. Baffle levees should be spaced 150 to 300 feet apart to facilitate water circulation. Core trenches in the baffle levees are not necessary. A recirculation canal, outside the perimeter levee, and a re-lift pump or paddlewheel aerator will aid in water circulation and minimize water discharge.
Ponds designed to recalculate water are important in areas where the quality of the surface water supply fluctuates or where well water must be pumped from great depths at great cost. Drains should be matched with the pond size, pumping capacity and projected rainfall. Two 10-inch drains are sufficient to drain a 20-acre pond. Ponds must allow vehicle access in wet and dry conditions and allow efficient use of harvesting equipment.
A set of Best Management Practices (BMPs) for crawfish production has been developed in cooperation with the Natural Resources Conservation Service (NRCS). These practices seek to minimize erosion, reduce the amount of contaminants (nutrients and pesticides) in effluent discharges and maximize the benefit to wildlife. Implementing these practices in the coastal zone of Louisiana is emphasized.
A Best Management Practice consists of a Conservation Practice as defined by the NRCS and a description of how this practice can conducted to have the least negative impact on the environment.