Minecraft wiki entry for Time-saving_tips, associated text: Whenever you have water and redstone circuits close together, and you are at risk of removing the wrong block and starting a flood, protect the redstone by placing doors or other blocks that cannot be waterlogged at key points. This should interrupt the water flow and prevent it from washing over your circuits. ‌[Java Edition only] Another alternative is to place one-block deep sinkholes to limit the water's spread. Either method saves time recreating your circuitry in the event of a flood.