Cover the water area with a solid block and have redstone repeaters facing the pistons. Connect them up with a line of redstone and drag it to the other end of the structure. Use a lever to turn them on and ensure all the pistons go down and are powered. If not you may need a ...
Most commonly, a Craftbook Integrated Circuit (or "IC") will consist of a block with a sign on one side and a lever on the other. The code on the sign, as well as any Redstone inputs from the front or sides of the sign, can affect the state of the lever on the other side....