Successful ponds begin with careful planning.
image by Photo by Moira Clune
To borrow a phrase from the real estate handbook, your primary concern when designing and building a pond is location, location, location. Site your pond incorrectly and you may have poor plant and fish growth, algae blooms and maintenance problems. The most successful backyard ponds begin with careful planning, so before you open the glossy pond supply catalogs, spend time on the preliminaries, such as drainage, sunlight and distance from your house. Take the time to understand your site so that your final pond design results in a beautiful, safe and easy-to-maintain addition to your landscape.
Decide on a liner. Preformed liners are easy to install and available at many home improvement centers, but your ultimate size and design will be limited. Flexible liners allow you to create a size and shape that meets your needs and fulfills your vision. The longest lasting liners are made of EPDM (ethylene propylene diene monomer), a nontoxic, UV-resistant and durable material that is available in a wide range of sizes up to 40 feet square.
Choose a sunny spot. A pond should have at least four to six hours of sunlight each day. Less than that and ornamental plants such as water lilies and lotus will not bloom profusely.
Choose an area away from runoff. Lawn fertilizers, driveway salts and household gray water can run into your pond and cause algae blooms or pH fluctuations. If your only viable location may experience runoff, build an earthen berm---a mound of soil---to divert water from flowing into your pond.
Plan for falling leaves. Excess organic matter in the form of fallen leaves will leave your pond with a layer of sludge that will promote algae growth. Site your pond outside the range of the heaviest leaf drop.
Avoid toxic or dangerous trees. Black walnut trees contain juglone, a chemical that may be poisonous to fish. Fruit and nut trees will contribute to sludge buildup, and the roots of large trees may grow under your liner and damage it.
Plan for easy access. You will, at times, need to add water to your pond, so access to a water supply will be helpful. If you are planning a pump, filter or water feature, you will need to supply electricity.
Decide on maximum depth. If you plan to keep fish and live in an area with severe winters, your pond will need to provide a place to hibernate. A depth of 2 to 3 feet is required. Deep water gives fish a cool hiding place on the hottest days of summer as well.
Design shallow areas. Shallow shelves around the perimeter of the pond are planted with marginals for decorative effect. These shallow areas also provide habitat for frogs, turtles and other wildlife. Shelves can be any depth between 6 and 12 inches.