Today, in our Inefficient Landscape Irrigation series, we are going to look at a seeping head.
One of the most common calls we get is from a homeowner reporting a broken head, usually at the foot of the driveway, and in many cases the head is not broken at all though there is definitely something that can be done to stop the leaking.
All heads are not created equal and while I will leave it to you to decide what brand will earn your consumer dollar, one of the things all homeowners should know is that low lying heads will always leak if they are not fitted with a specialized check valve.
When a system activates, water flows and the pressure forces the stem of the head up which activates the nozzle and delivers water to the landscape. Once the water has been delivered, the system deactivates and the stems return to their retracted position. Heads lower than the control valve and lateral pipe lines will then slowly drain all of the water stored within those lateral lines over the coming minutes or hours depending upon how much water is stored within the pipes. This pressure is not significant enough to activate the head and instead the head slowly seeps water until the lateral lines are drained. Gravity pulls the static water to the lowest possible outlet which is usually the heads along the sidewalk or street curb. This seeping is a waste of water and can cause a number of issues but it is not indicative of anything being broken. If the lateral lines in the front yard hold 50 gallons of water and the system runs every Monday, Wednesday and Friday, a homeowner could easily be losing 150 gallons per week and in excess of 600 gallons per month.
The solution is to retrofit the sprinkler heads in low lying areas, especially those that border the sidewalk and street, with heads that feature a built-in check valve in the base of the unit. This check valve will allow the head to function properly under normal operating pressure but will not allow water to pass through the body when the system is not in use. Note that if a head is leaking and is higher than the valve and lateral lines then the problem is most likely a seeping valve which is a valve not closing all the way.
The video below will let you get a look at low head seepage. Please don’t hesitate to ask us for help or to send any questions you might have and, as always, happy gardening! – John