October 2012
5-9
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EPA’s WaterSense program. Rainwater & Reuse.
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EPA’s WaterSense program,
op. cit.
,
Page 41.
5.2
Landscaping
and irrigation methods affect the ability of a landscape to meet a water budget
based on the local climate. The Water Budget Tool is not intended to estimate
actual savings, but it is a tool to help evaluate the relative water savings that can
be achieved with different plant palette and technology choices.
••
Consider installing a separate meter to measure the volume of water applied to
the landscape. Separately metering irrigation systems can reduce wastewater
costs in some jurisdictions and can help to identify leaks more quickly.
••
Consider where alternative water sources can be used as a substitute for potable
water sources for irrigation. Information about rainwater harvesting and reuse
can be found on the WaterSense website
21
or see
Section 8: Onsite Alternative
Water Sources
for more information.
Other Features
When planning hardscape retrofits, consider the following
to enhance outdoor water efficiency:
••
If replacing sidewalks or parking lot pavement, consider
installing permeable surfaces (e.g., permeable pave-
ment) rather than impermeable hardscape.
••
Use bushes, mulch, rain gardens, permeable hardscape,
or curb cuts in parking lot islands or in the areas be-
tween sidewalks and the roadway. These should be at
a lower elevation than surrounding hardscape so that
runoff flows into them.
••
While water features are common in many landscapes, consider the annual water
use of the specific feature before installing one. Ideally, these features should
provide a beneficial use, such as a wildlife habitat, stormwater management,
and/or noise reduction. Because water from these features is often lost to evapo-
ration, use alternative water sources or look for a feature that recirculates water in
order to reduce the amount of potable water used. Smaller pumps, lower pump-
ing rates, and/or pressure-reducing valves can help reduce water flow.
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Savings Potential
Landscape water use is largely dependent upon climate, plant type, and an irrigation
system’s efficiency. Soil health, grade, and maintenance also play a role. In order to
evaluate landscape improvements and their associated savings, one must first know
how much water is being applied to the landscape. Dedicated irrigation meters can
be used to track irrigation water use and document savings from various measures.
Savings for converting high water-using landscapes to low water-using landscapes
vary by plant type and climate. Keep in mind that calculations are property-specific.
In general, various studies have reported savings ranging from 18 to 50 percent from
Rain garden
