BOARD00164 ‎(2)‎

• Board Meeting Date: 5/22/2007
• Description: OWCDP Section - Presentation by the Center for Resource Conservation - Impacts and Findings of the Slow the Flow Colorado Irrigation Inspection Program
• Board Meetings - Doc Type: Memo

7

"

Executive Summary

.

Purpose of Report
This report is intended to summarize the impacts of the Slow the Flow Colorado
Irrigation Inspection program on the outdoor (landscape) water use of program
participants in the years 2004 and 2005. This report details the methodology and results
of the analysis. Funding for the study was granted by the Colorado Water Conservation
Board.

Proe:ram Ristorv
Slow the Flow Colorado is a program that strives to reduce outdoor water waste by
improving upon the efficiency of landscape irrigation systems and educating property
owners on landscape best management practices. This is accomplished by providing
irrigation system inspections (otherwise known as irrigation audits) at no charge to
properties along the Front Range. Slow the Flow Colorado is closely modeled after a
successful program developed by the Utah State University Cooperative Extension called
Slow the Flow save H20 and was adopted in 2004 in Boulder County, Colorado as a pilot
program ofthe Center for ReSource Conservation (CRC). The clear demand for
inspections during its pilot year prompted the CRC to implement Slow the Flow
Colorado as a permanent program of the Western Water Conservancy (WWC), a division
of the CRC. Each year, funding for the program has been procured from the participating
cities and utilities as well as the Colorado Water Conservation Board.

Data
Several key pieces of data needed to be gathered, processed and analyzed in order to
perform the analysis of Slow the Flow Colorado. on reducing outdoor water use. These
key data pieces included water consumption (gallons) and landscape size (sq. ft.) for each
audited property, as well as annual evapotranspiration rates for Bluegrass (in.).
Evapotranspiration rates for turf grass determine how much water needs to be replaced
through natural precipitation and/or irrigation for the plant to survive.

.

The analysis utilized water record data for households that received an irrigation
inspection in either 2004 or 2005. The CRC was responsible for processing all of the
water records obtained from the participating cities and was subsequently able to estimate
the amount of water used outdoors. To determine the effects that Slow the Flow
Colorado had on outdoor water usage, each household's water usage before the
inspection and after the inspection was analyzed. Equivalent amounts of data were
needed for pre and post inspection analysis in order to make comparisons. In 2004 only
one year of pre-inspection data was usable because 2002 (two years pre-inspection) was a
major drought year in which significant mandatory watering restrictions were in effect.
For the 2005 study group, only one year of post-inspection data was available. Therefore,
for both study groups only one year of pre and post-inspection data was analyzed.
Consideration of factors that might occur/change annually and affect watering behaviors
(such as drought or watering restrictions) deemed that the 2004 participants be analyzed
separately from the 2005 participants. All outliers and unusable data were removed from
the two groups.

.