Is Rainwater Collection Legal in Louisiana? In fact, rainwater collection is encouraged here, which makes sense in a state that gets this much of it. Under the Louisiana Administrative Code, rain barrels, cisterns, and other collection containers have to be properly installed and maintained to prevent mosquito breeding. We can go weeks without meaningful rain, and that's exactly when a stocked rain barrel earns its keep for the yard, the flower beds, and the garden. Get a barrel, seal it up, and let Louisiana's rain do some work for you.