The problem with this and much of the area nearthe sea coast in Gaza is sandy soil which makes ponds that don't leak difficult or impossible to make. One solution is to build the ponds near or at the bottom of valleys where there is more clay, but often this makes the ponds undrainable and nearly impossible to harvest as the ponds are kept full of water simply from being dug into the water table. Small scale ponds often range from 100 square meters to 300 or 400 square meters surface area.