The greatest benefit of all may be how ponds enhance the environment. Sources of open water accessible to wildlife are scarce in suburbia. Insects, birds and animals may travel considerable distances to visit your pond, especially in times of drought or freezing weather. Many of these visitors will stick around if you design your pond as a wildlife refuge, providing food, shelter and a place to raise young.
You'll find that many native and indigenous plants you can include around your pond will provide food for native wildlife. Check with your local cooperative extension, arboretum or botanical garden for guides to the local plants available in your area, or research them on the Internet.
All organisms need shelter for sleep and hibernation, for protection from weather and predators, for breeding and raising offspring. Unfortunately, our need for shelter competes directly with wildlife. As we build more and more housing for ourselves, there's less for the wild vegetation and animals we share the planet with. Ponds are ideal habitats for lots of organisms like insects. As soon as a pond is in, water striders, water boatmen, dragonflies and damselflies somehow find it. All they need is the water and a plant stem to land on. Larger animals like the shelter of the pond too, especially amphibians. Frogs, toads, newts and salamanders literally absorb oxygen through moist skin, so they need a wet environment to survive, reproduce and to breathe. Other species appreciate the pond area too, like the birds that bathe and nest around the pond; rabbits, chipmunks, shrews and mice that live in the vegetative cover; turtles, snakes and lizards as well as the occasional thirsty raccoon, opossum or even deer.
Ponds are tailor-made to provide water to native wildlife. Regardless of which ones need a wet environment, all of your wild neighbors will appreciate a nice, cool drink. Sources of clean water are actually very valuable to wildlife year-round and, even more important, during droughts, dry seasons or frozen winters.