Controlling water levels is and important part of pond design. Maintaining an adequate volume of water is essential for the health of organisms living in the pond as well as the pond's appearance on your property. Whether you will be travelling for extended periods or simply want to avoid the hassle of refilling the pond, installing a float valve in your pond will automatically refill your pond when the water level drops. In addition, incorporating a well-designed overflow drainage system helps ensure that your pond levels remain steady, even in heavy rains.
Securely fasten the float valve to a water source. Many pond float valves have variable attachments and can be used with a standard garden hose or irrigation lines on your property.
Turn the water on to a slow flow rate. Ponds lose water slowly by evaporation and a slow flow rate from a garden hose is enough to resupply any water lost and control the level in your pond.
Install the float valve in a stable location at the edge of your pond and adjust the valve to the desired water level. The valve floats on the water surface. When the valve drops below the desired water level you set, water is allowed to flow until the water level is restored.
Monitor the float valve when conducting routine maintenance on your pond and adjust the float valve as needed.
Determine the maximum water level of your pond and dig a small depression to that point in the berm surrounding your pond.
Place rubber tubing -- 1 to 2 inches in diameter -- in the depression and use silicone adhesive to attach the tubing to the pond liner. Be sure to keep the area dry to allow the adhesive to form a secure bond.
Lay the tubing out so it terminates in an area lower than the pond water level. Choose an area away from structures or locations prone to flooding.
Dig a hole 2 feet in diameter and 2 to 3 feet deep at the end of the tube where you want the overflow water to drain.
Fill the hole with gravel and bury the course of the tube to hide it. The stones provide an area where the overflow water can drain into the soil without creating a soggy area on your property.
Water that is continually running from the float valve may be a sign of a leak rather than replenishing losses from evaporation.