Twenty years ago, Garden Founder Dan Lutkenhouse envisioned adding a large pond in the center of the Garden as a home for Koi and Goldfish and as a showcase for Water Lilies and other aquatic plants. He and the Garden staff excavated the pond by hand and it became a highlight for all visitors to enjoy the brilliantly colored fish and Lily blossoms. Dan proudly named it Lily Lake.
Two decades later a major effort was needed to return Lily Lake and its surroundings to its original luster. The Garden enlisted the help of local water feature expert and retired engineer Alex Burgess. This project included a complete cleaning of the lake floor, a new rock wall for safety and beauty, and most importantly, a new natural wetland filtration system to keep the water clear.
A wetland filtration system eliminated the need for expensive filters and costly maintenance, while adding beautiful aquatic plants to the area. Plants such as Water Lettuce (Pistia stratiotes) , Water Hyacinth (Eichornia crassipes) and Pickerel Weed (Pontederia cordata) are known to be excellent at removing a lot of the nutrients in the water that pond polluting algae need to thrive.
Because these plants can become invasive, Lily Lake remains self contained with no cross contamination of pond water into the valley’s streams or oceanfront.
To create the wetland area, a 100 ft long trench was dug by hand around one-third the circumference of the lake.
The trench was then lined and filled with gravel and plants. The water is circulated through the wetland starting with a spill over a boulder waterfall, then a passage through an 80-foot long settling area filled with floating plants (Water Lettuce), followed by a flow through a gravel-filled planted section (Pickeral Weed and Water Hyacinth) which is aerated and charcoal filtered at the end. Finally, the water exits back into the lake over a spillway.
Moving the water through this system are three high efficiency pumps and one aerator. Each pump serves a separate function. The first pump draws water from the end of the wetland and discharges it through jets in the lake, which slowly rotates the water. The second pump skims the surface water, removes leaves and floating debris, and discharges it over the waterfall. The third pump takes water from the bottom of the lake and pumps it over the waterfall. The three pumps can circulate 18,000 gallons per hour.
Protecting the water and air pumps from the weather is a small pump house. To preserve the Garden aesthetic, the pump house roof is covered with pond liner and a layer of epiphytic soil mix and planted with mosses and ferns to complete the disguise. This green design makes it indistinguishable from the surrounding jungle.
A wide pathway and an artfully crafted serpentine rock wall now surround the lake, and benches invite the visitor to sit and enjoy the koi and goldfish that frolic at the lake edge.
Carefully chosen plants for ground cover add greatly to the natural serenity, while reducing maintenance. The results of all these efforts are clean water, happy and active fish, beautiful scenery, and a new life for Lily Lake.