Page 166 - WaterSense at Work

October 2012
Soil moisture sensors can be inserted into the soil to measure moisture. They
can be connected to an existing system, enabling irrigation as needed by plants.
Consider installing rain-sensing technology to prevent irrigation from taking
place during periods of sufficient moisture. Many cities and some states require
rain-sensing technology by law. Check with the state or city on relevant man-
Consider installing other sensors to cut down on wasted water. For example,
wind-sensing technology interrupts irrigation cycles in the presence of signifi-
cant wind. Freeze-sensing technology prevents irrigation during freeze condi-
tions. Flow rate-monitoring equipment can interrupt irrigation if excess flow is
detected (i.e., caused by broken pipes, fittings, emitters, sprinklers, etc.).
If managing a large property, consider installing complete central control sys-
tems that use demand-based controls to enable a water manager to centrally
operate and manage multiple irrigation systems at multiple locations with vari-
ous means of communication.
Irrigation System Hardware
In addition to retrofitting the control system to decrease water use, a facility can con-
sider retrofitting irrigation system hardware as follows:
Consider retrofitting a portion of the spray heads that water trees, shrubs, or
plant beds with low-flow, low-volume irrigation, also called micro-irrigation or
drip irrigation. Many plant beds do not require the spray heads traditionally used
to water turf areas.
Consider exchanging existing sprinkler heads with more efficient heads designed
to minimize water lost to wind and distribute water in a more uniform man-
ner. Sprinklers with a fine mist are susceptible to water waste from wind drift.
Also, some sprinklers do not apply water evenly over the landscape. Consider
pressure-regulating heads with matched precipitation and/or multi-trajectory
rotating spray heads as water-efficient sprinkler head options.
Pay attention to sprinkler head spacing during replacement to ensure the heads
have matched trajectories and offer head-to-head coverage.
Retrofit other water-using devices on the property to use water more efficiently.
For example, attach shut-off nozzles to handheld hoses to make sure water is go-
ing directly to the plants rather than dripping on the ground.
Replacement Options
If replacing an irrigation system, there are as many opportunities to increase its
efficiency during the phases of system design and installation as there are during
system operation and maintenance. Hiring qualified irrigation professionals and
ensuring a well-designed system are key to ensuring water savings from an irrigation
system replacement.