Building Pondless Waterfalls

Benefits

• Waterfalls benefit landscapes and wildlife. Pools and ponds create drowning hazards for small children, however, and pondless waterfalls offer a safer alternative. They empty into gravel or rock beds where the water disappears into underground catch basins. Birds and other wildlife are still attracted to the running water, but mosquitoes do not accumulate because of the absence of standing water. Pondless waterfalls require little space because their “ponds” are underground, and maintenance is minimal because there is no above-ground pond to keep clean.

Site

• Pondless waterfall catch basins are underground, so they are constructed where digging is not too difficult. Bedrock or hardpan sites create digging obstacles and are not good choices. Recirculating pumps need electrical outlets to access power, so your waterfall should be situated close enough to an existing exterior power outlet for the power cord to reach. If your waterfall is designed out-of-reach of an existing power outlet, you’ll need to have an electrician install an electrical outlet box within cord reach.

Materials

• A catch basin is required for all pondless waterfall designs. You can use a rigid molded catch basin, or you can excavate the soil and lay down a waterproof pond liner. Recirculating pumps are available in different sizes, depending on the height and run, or length, of the waterfall. An automatic pump timer is optional, but it allows a more energy-efficient operation of the waterfall. The basin filler is composed of different sizes of pebbles, gravel and larger stones. Tubing connects the submerged recirculating pump to the waterfall weir, which is located at the top of the waterfall.

Construction

• Most holes for catch basins should be excavated to a depth of 18 to 24 inches. After the rubber pond liner is put down, and the hose is attached, the lined basin is backfilled with rock or gravel. Large rocks are laid first and smaller gravel or pebbles are poured in around the large rocks to fill in the spaces. Another rubber liner is placed under large rocks or boulders, which are stacked at one end of the gravel-lined basin, to provide the drop for the waterfall. Tubing from the recirculating pump is attached to the top of the waterfall weir to allow water to cascade down the boulders. The basin is filled with water and the pump is plugged in, which begins circulating the water.