Water treatment facilities require power and are used to keep water bodies clean. Water treatment is essential for animal welfare as it provides them with clean drinking water and reduces the chance of disease. The cleanliness of water also gives guests better views of animals through clear water.
Guests are not impressed by seeing water treatment facilities and being near them will make them unhappy. A water treatment facility will clean any body of water within its radius, even if partly outside its radius.
Water treatment facilities deteriorate and lose efficiency over time. Once a water treatment facility's efficiency reaches 50% its effective radius will start to shrink. This may mean that they stop cleaning water bodies. When the efficiency rating reaches 0%, the water treatment system will fail completely.