The primary reason to drain the pond at the end of the crawfish season is to be able to plant a new crawfish forage for the next crawfish season and to eliminate any fish that were able to enter into the pond. Draining the pond is not a necessary step in the biology of the crawfish. They can survive and thrive in a continually flooded pond as long as there is adequate food, limited predators, and adequate water quality. Currently, there is not a nutritionally complete crawfish diet available on the market or an economical method of eliminating crawfish predators that may have gotten established in a crawfish pond. Therefore, crawfish ponds need to be drained at the end of each season.
Timing is very important when draining crawfish ponds. They need to be drained at the end of the crawfish season before temperatures become too warm. This time usually corresponds to the month of June in North Carolina. It is again important to remember that the maximum lethal temperature for crawfish is about 95oF. Another indication that it is time to drain the crawfish pond, other than temperatures, is when you see a significant increase in burrowing activity in the pond levee.
Ponds should be drained slowly, as when the ponds were drained after stocking, at a rate of about one inch per day. If ponds are drained faster, the crawfish will not be able to burrow fast enough and will become stranded out in the open in the hot sun and water, usually perishing. Adding cover in the form of a light layer of hay, straw, or pieces of cardboard around the water's edge can give the crawfish some protection from the hot sun and predators and encourage their burrowing. Another method of assisting the crawfish in their burrowing is to pump fresh, cool water into the pond as it is being drained. This not only moderates the water temperatures to some degree, but adds moisture to the pond bank softening it and aiding in the burrowing process. However, if the pond has an overpopulation problem, draining the pond quickly and stranding crawfish can be used as a management tool.
Once the pond is dry, farm equipment can enter into the pond and begin planting the forage for the next year. There is no reason to worry about the equipment destroying burrows and killing crawfish. By the time the pond is dry enough to support farm equipment, the crawfish have burrowed deep enough to avoid the plow discs and crushing weight of the equipment. Those crawfish not deep enough to avoid these hazards are not deep enough to survive the hot, dry summer and will die anyway.