How to Make a Laminar Flow Waterfall

Determine the waterfall's location. If the ground is soft, you can excavate to make the waterfall. If not, you can build the waterfall above ground. When choosing the location, consider the fountain's length as well because you'll need about 5 gallons of water for each linear foot of flowing water. Keep in mind that the waterfall's lower basin, where the pump sits, must be near an electrical outlet and hose.

Outline the shape of the upper pool and lower basins and the path of the waterfall with a long length of rope. If you're making a stream with a 75-gallon water capacity, for example, the upper pool and lower basin should have a diameter of about 4 feet. After you're pleased with the shape you made with the rope, outline it with spray paint used for sports fields. Remember that the upper pool should be on ground that’s higher than the lower basin.

Dig out the lower basin. The hole should be 2 feet wider than the diameter of the sump basin and 6 inches taller. For example, if the sump basin is 2 feet wide and 2.5 feet high, the hole should be 4 feet wide with 3-foot-high walls. Your basin should also be 12 inches wider than the waterfall's stream.

Cut the underlayment fabric so it fits inside the basin you just dug and extends an extra 2 feet in all directions. Cut an EPDM pond liner to the same size.

Prepare the sump basin. Drill 2-inch holes using a 2-inch hole saw bit along the lower third of the basin. Drill 1-inch holes in the middle third of the basin with a 1-inch hole saw bit. The holes along the top of the basin should measure 3/8 inch. Space all the holes 4 inches apart.

Attach the hose adapter to the waterfall pump using PVC purple primer and PVC cement. Follow the manufacturer’s instructions when using the primer and cement.

Place the sump basin in the middle of the lined hole and place the waterfall pump inside the sump basin.

Connect one end of the water line to the laminar nozzle and the other end to the pump. The water line should be long enough to extend from the pump to the upper pool along the side of the waterfall and its stream.

Place the lid onto the sump basin and fill the hole around the basin with 2-inch stones. The stones should be level with the top of the sump basin.

Use 6-inch stream boulders to outline the shapes of the waterfall's banks and its stream. Use 12-inch boulders, flat side up, to outline the upper pool.

Build the waterfall path and steps. Add dirt along the path of the waterfall stream so there's a gentle slope from the top pool to the lower basin. The stream should be about 6 inches deep and a foot narrower than the lower basin. When you make a waterfall step, such as from the upper pool to the next level, the edge of the step should have a 90-degree angle. The bottom of each step should contain a shallow, 3-inch-deep pool. The pools will help slow the flow of water.

Form the upper pool. Lay down an inch of a dirt and gravel mixture. Use a rubber mallet to pack the dirt mixture tightly around the 12-inch boulders.

Use a hand tamper to compact the dirt in the upper pool and along the length of the waterfall.

Place the fabric underlayment and pond liner along the length of the waterfall and its streams. Leave some slack at the base of each waterfall step. The liner should extend 2 feet on either side of the waterfall, as well as overlap the basin liner by 2 feet.

Cut and place a fabric underlayment and pond liner so it fits inside the upper pool and extends 2 feet past the 12-inch boulders on all sides. Use gravel to backfill the outer edge of the boulders for added stability.

Place 12-inch boulders on top of the liner, over the boulders you previously placed along the upper pool.

Place large decorative boulders and field boulders along the edges of the waterfall and stream. If you place any boulders above ground, backfill the outside edges with a dirt and gravel mixture for extra stability.

Fill the lower basin with river rocks and gravel.

Cover the liner at the upper pool with gravel and river rock. Be gentle around the laminar nozzle.

Use flat flagstone at the top of each of waterfall step. Coat the bottom and sides of the flagstone with waterfall foam sealant. The sealant will make the flagstone stick to the liner and prevent water from flowing underneath the rock. Let the sealant dry for 30 minutes.

Fill the length of the waterfall and its streams with small boulders, river rock and gravel. Wedge stones and gravel in the cracks between the larger rocks to give them more stability.

Use your garden hose to fill the lower basin with water. Turn on the pump and continue to fill the waterfall with water. When the water coming out of the waterline is clear, place it into the upper pool in a manner that keeps the line and laminar nozzle out of sight.

Trim the edges of the liner.