05-13-2018, 12:24 PM
If you put a tarp on a catchment tank and don't have the means to keep it from collecting water itself it can sag and bend (ruin) the frame of your catchment tank cover. In a worst-case scenario the tarp will sag down into the tank holding its own water plus what it's holding on top, collectively putting 11,000 gallons or more of water into a tank designed to only hold 10,000. It would be kind of like removing your overflow spigot. The tanks aren't engineered to be filled to the brim. 1,000 gallons of extra water would put over 8,300 pounds of stress pressure on the tank and making bursting a possibility.