The sparkle of a stream, the splashing of a fountain, the glimpse of golden fish, the delicate petals of a water lily-all these and more are reasons to add water to your landscape. A water feature can be as simple as a wooden tub or as elaborate as a stream with bridges, waterfalls and pools of exotic plants and fish. It can be a formal tiered fountain centered in a patio, or a pool so natural your guests will assume it's always been there. And most water features-no matter what type you choose-are terrific do-it-yourself projects. Water gardens were favorites of the Moors, for whom water was a symbol of life and purity. They positioned cooling fountains in the middle of their formal courtyards to signify the primacy of water. Early Asians, too, valued water gardens as an aid to meditation and delighted in breeding rare fish. In ancient times, Chinese nobility would spend their afternoons lolling in small boats on water gardens while servants floated tea-filled cups to them on lily pads. For Renaissance Italians, water was a toy. They loved ornate fountains and whimsical sprays some designed to squirt unsuspecting strollers and installed them throughout their estates. Today, water gardens have again grown popular, even in our humbler yards. Like the gardeners before them, modern homeowners find that water features are beautiful and peaceful additions to the landscape. Unlike the past, today's gardeners have better tools and materials with which to build their pools. Flexible and preformed liner materials, for example, have revolutionized design and scaled down installation. Water gardening is easier than ever, and even if you're an amateur, building a garden pond today is limited less by your wallet than it is by your imagination. Once, you might have only dreamt you could have a water garden this beautiful. Now you can build it yourself. It takes planning and effort, but the end result will transform your backyard landscape.