Preventing Low Head Drainage in Sprinkler Systems on Sloped Landscapes

Low Head Drainage in Sprinkler Systems on Slopes

If you have a sprinkler system installed on a hilly or sloped area of your property, chances are you may have a system that leaks water at the sprinkler heads for a short time after the system is turned off. This is something called low head drainage.

With ups and downs in the sprinkler system, water tends to find the lowest points in the pipes when the system is off. Water then drains out of the lowest sprinkler heads and spills out onto walkways and sidewalks or collects in a puddle. That’s all wasted water; it could add up to a lot of wasted water.

The slope doesn’t even have to be that extreme for this to happen; even a change in elevation of about a foot or less can cause this problem. 

The other problem with low head drainage is that it pulls air into the lines, which results in noisy, spitting sprinklers each time they start.

The Ecoyards crew often sees a lot of low head drainage issues in Seattle landscapes, which tend to be hilly or sloped. When clients approach us with this problem, we install a simple device called an anti-drain valve, or check valve, at the sprinkler head. These valves prevent the water from draining out of pipes through the lowest sprinklers.

On new sprinkler system installations, we use sprinkler heads with built-in check valves to prevent this problem. The devices close and hold the water in the pipes when the sprinkler system is off.

Contact us for help dealing with the problem of low head drainage.