Keep the tap on in wintertime
In regions with cold climates, a common problem for caretakers is preventing water from freezing during the winter. The cats need water on a regular, daily basis. This need is heightened when dry food is used as the staple diet, something that may become necessary when the moisture in canned food causes it to quickly freeze and become inedible. A number of solutions exist - some will completely stop freezing while others delay it. Which works best for you will depend on the circumstances of the colony, but there's something for everyone!
Electric heated water bowl
If you're able to run a cord to the feeding station, an electric heated bowl will ensure a supply of unfrozen drinking water. The water will evaporate quickly, so you need a bowl that holds at least one gallon and you'll need to refill it daily. Some caretakers also use electric bowls for wet food, but be aware the heat will dry up the food soon after it's placed in the bowl. The bowls come in stainless steel and plastic and a variety of them can be found online by searching for "heated pet bowl." Pictured here is a stainless steel dish (item no. 84081) from KV Vet Supply. It holds 5 quarts and comes with a 6 foot weather-protected cord. A plastic model the same size but less expensive is also available from the same vendor (item no. 84080).
The Solar Sipper has a specially designed top with a 4 inch opening that uses the sun to keep water from freezing down to 20 degrees Fahrenheit. In warmer weather, its insulating properties help keep water cool. It holds one quart of water, is manufactured by the Happy Bird Corporation and can be purchased at a number of online retailers, including Walmart and Plow & Hearth. For other vendors, search for "Pet Solar Sipper" or "Deluxe Pet Sipper."
Snuggle Safe Microwave Heat Pads
These plastic discs, about the size of a frisbee, can be heated up in a microwave and then placed underneath a water (or food) bowl to prevent freezing for approximately two to three hours in frigid temperatures. One caretaker reported a disc can be safely heated for 8 minutes in a 1000 watt microwave to maximize its heating potential. Because microwave ovens differ, be cautious at first when "cooking" to make sure the disc doesn't melt. If you buy two, you can bring a fresh one with you to the colony and swap it for the one you put out on your last trip. This product can also be wrapped in cloth and slipped inside the cats' shelter for added warmth. Online distributors include Entirely Pets and the Snuggle Safe company itself, which is based in the United Kingdom.
Freezing can be delayed by placing the water bowl inside a small Styrofoam cooler - the kind used to pack lunches on picnics or keep beer or soda cold, like the 30 quart version available for only a few dollars at Walmart. Cut a doorway in one of the short ends, leaving the bottom of the opening a few inches off the ground to prevent flooding. At the colony site, place the water bowl inside and close the lid. Weigh down with a brick or heavy rock. Be careful to use only a small Styrofoam container, one large enough to hold the water bowl and no more than one cat in a drinking position. You don't want the cats hanging around inside. If they use the "water station" as a shelter, they could get wet which would threaten their health in cold temperatures.
The Right Kind of Bowl
The type of bowl you use can make a big difference in the speed at which water freezes. Containers with thick plastic walls, like Tupperware, are better than thin-walled bowls. Deeper bowls with narrower openings will delay freezing more than containers that are shallow and have relatively wide openings. Dark-colored bowls will absorb more heat from the sun than lighter ones. It also helps to position the bowl so it is out of the wind, but exposed to sunlight.
A small Styrofoam shipping container (approximately 8 inches square and 4 inches deep) can be turned into a well insulated water bowl that will slow freezing. Line the inside of the container with a thick plastic bag, then cut a hole in the top large enough for a cat to drink from. Fill with water. Vaccines are often shipped in this size Styrofoam container, so ask your veterinarian if she can save one for you. (This great idea courtesy of Susanne Mahar at Noah's Kingdom Humane Society).
Tires and rocks
Here's an old trick used by horse owners to keep buckets of water out in the pasture from freezing. Take an old black tire (that's off its rim) and fill it with rocks. Then tightly wedge a large bucket in the tire's hole and fill with water. During the day, the tire absorbs sunlight and heats the rocks stuffed inside. The rocks in turn radiate heat and keep the water from freezing. For another way to use old tires to prevent freezing water, check out Mother Earth News.
Does your colony frequent a back alley in an urban area? If so, there may be heating pipes just inside the exterior walls of neighboring buildings. Placing a water bowl near one can slow freezing. One way to find where the pipes are, besides feeling for warmth, is to notice if there is a spot near a wall where the cats tend to gather in cold temperatures. It could be that location is warmed by a heating pipe.
Wet food tip
Do your cats come running over as soon as you show up to feed? Take advantage by giving them some wet food right away with extra water mixed in. Cats don't usually need much water, so this could be a big help if it's otherwise difficult to keep water available.