You’ve turned off your sprinklers and notice that water is flowing onto the sidewalk or curb but then stops after a few minutes. Clearly, there’s a problem and one that’s compounded by the fact that you have to deal with water usage restrictions as well. What is going on? And how do you do deal with it?
The phenomenon you’re seeing is probably due to something called “low head drainage.” This typically happens when a sprinkler system is installed on a sloped area. The slope itself doesn’t have to be sharp. A change of elevation that’s less than 12 inches can still cause problems.
The main difference between low head drainage and a leaking valve (which could also explain the water overflow) is that low head drainage results in water flowing from the lowest sprinklers for a period of time after they run but all drainage stops after the pipes or empty. If the valve is leaking, water will run out of the lowest sprinkler head 24 hours a day until the valve is fixed.
To correct a low head drainage problem, you need to install special anti-drain check valves at the sprinkler heads. These devices prevent water from draining out of the pipes through the lowest sprinklers. Most major sprinkler brands can be retrofitted with a new internal check valve: unfortunately, though, retrofit kits can be difficult to find. You may find it easier to just buy a new head with a check valve feature and replace the old sprinkler with a new one.
Since this kind of equipment is not available at hardware stores, you’ll likely have to buy it online or from a local irrigation specialty store. The experts at South Austin Irrigation can advise you on where to purchase sprinklers with check valves or retrofit check valves and can also help you with the actual installation. Contact us today and let us help you save time, money and water.