Irrigation and Water Management
Real-world Watering
Why low precipitation rates aren't always the answer
t's no secret that many property owners
tend to overwater their landscapes.
Some overwatering is due to a lack of
knowledge about proper watering
practices; some results from simple
carelessness.
According to the EPA's WaterSense
Program, the average American home uses
about 260 gallons of water a day. However,
during the hotter months of the year, that
number can increase to a whopping 1,000
to 3,000 gallons per day — that's the same
amount as if a garden hose was left running for eight consecutive hours. Even
worse, experts estimate that 50 percent of
all water used outdoors goes to waste due
to evaporation, wind, deep percolation or
runoff. Considering this is happening at
homes and businesses throughout the
I
country, the amount of irrigation water
we're wasting is staggering.
The low-down on low-precip nozzles
Most water agencies are aware of these
numbers, and many are working with city
governments to offer rebates for more efficient irrigation system components, such as
weather-smart controllers, rain sensors and
drip irrigation. Because almost every irrigation system also features sprays, some communities are now also offering rebates to
property owners who replace their standard
spray nozzles with those offering a lower
precipitation rate. These "low-precip" nozzles emit water at a slower rate; this means
that, when operated for the same amount of
time as a standard nozzle, they don't apply
as much water to turf.
"In addition to peak demand management, there's another dominant reason
why cities and water agencies are encouraging the use of low-precip nozzles," said
Randy Montgomery, Rain Bird Corporation's product manager for contractor spray
nozzles. "The general belief is that homeowners in particular don't know how to
use their irrigation controllers well enough
to change their watering schedules as
needed — or they simply forget to do so.
Water agencies believe that if customers
switch out their current nozzles for lowprecip versions, they'll use less water —
even if they never touch their controllers.
This is certainly true. However, it's a strategy that relies more on behavioral modification than education, and can still result
in inefficient water use."
Photo provided by Rain Bird
The Karsten Turf Research Facility at the University
of Arizona in Tucson is testing the effects of realworld conditions on nozzle performance.
16 Landscape and Irrigation April 2013
www.landscapeirrigation.com
