Audit of Major Commercial & Irrigation Water Accounts

• Project Type: General OWC
• Applicant: Town of Castle Rock
• Project Name: Commercial & Irrigation Water Audit
• Title: Audit of Major Commerical and Irrigation Water Accounts
• Date: 6/29/2006
• County: Douglas
• Water Conservation - Doc Type: Final Report

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Audits of Major Commercial and Irrigation Water Accounts
Town of Castle Rock

be increased, and for some of the biggest irrigation water users, the savings can be
substantial.

For example, for the four smallest irrigation accounts (Escavera, Castlewood Ranch,
Metzler, and the Founder Village HOA (that the Town pays for), a 14 zone ET controller
can be purchased, installed and programmed for about $1200 including tamper proof
housing. The reduced cost of water associated with the installation of the ET controller
for these accounts is less than one irrigation season under current water prices, and less
than one month using the water budget pricing.

For the next set of accounts, including Founders Village (paid for by the Town), Pines at
Castle Rock and Common Grounds, a more complex ET controller is required, costing
between $5,000 and 10,000 to purchase, install and program. For these accounts, the pay
back for this investment under current pricing will likely occur in 1 to 2 irrigation
seasons, although for some accounts the pay back under water budget pricing may be less
than one month.

If just the over watering of streetscapes, multifamily areas and parks associated with
these ten accounts in 2005 occurred, the Town would have saved over 80 acre-feet of
potable water.

Table 9 summarizes the cost for retrofitting the various irrigation landscapes with a
mixture of hardscape and xeriscape materials, and the expected payback period, based on
the average cost of water for 2004 and 2005 using the water budget model.

Based on this analysis, the majority of the irrigators could pay for installing more
efficient landscape in less than one year. Even if the costs for working in the median
strips and along the various roadways proved to be 3 to 4 times as expensive as indicated
by Target and the Y ARDX research, the payback period for most locations would be less
than 2 years. Only Butterfield, which has already implemented a turf replacement
program and Meadows Parkway have payback periods often years or more.

Also note that in locations such as Butterfield Park, complete turf replacement with
xeriscape and other water efficient planting since this material is not suitable for all
public play areas and athletic fields. The Town may want to install synthetic turf in some
of the athletic fields as an alternative (noting that Douglas County already has more than
a half dozen of the synthetic turf fields installed in parks).

The Town's 10 largest irrigation accounts studied in this project used nearly 100 acre-feet
in 2004, and over 136 acre-feet of water in 2005 irrigating nearly 1.9 million square feet
of turf. Using a price for new water as $10,000 per acre-foot, the water savings afforded
by the turf replacement program represents over $1,000,000 in replacement water costs,
which is about the cost ofthe turf replacement programs for all ten accounts.

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