Arvada 1996 WCPlan

• Project Type: Water Conservation Plan
• Project Name: Arvada Water Conservation Plan
• Title: Water Conservation Master Plan
• Date: 6/25/1996
• County: Adams
• County: Jefferson
• Water Conservation - Doc Type: Complete Plan

over-or-under watering. Another major shortcoming of the existing manual system is the
requirement to visit each site to shut off irrigation during rainstorms and high winds --
and turn on again when environmental conditions are acceptable -- an impossibility with
the present staff of 24 employees.

In 1988, the combined water use for all 123 sites was about 227 million gallons.
Historically, efficient watering of these sites has not been the norm. Little attention has
been given to (I) watering according to ET requirements, (2) accomplishing close field
monitoring of the 123 sites for problems and opportunities to save water, (3) or keeping
records of water use by site, (4) evaluating the data, and then (5) taking corrective
actions. Water use records for all sites in 1989 are still not available. However, the
Public Works Department's Staff's involvement in evaluating computerized irrigation
control systems and analysis of the inefficient irrigation practices at the Arvada Center
and the median in West 80th Avenue between Wadsworth and Club Crest Drive served to
improve irrigation attention at these sites in 1989. However, the lack of attention to the
volume of irrigation water applied at the Arvada Xeriscape Garden in 1989 contributed
to more than three times the needed water being applied there. This further supports the
critical need for the City of Arvada to install a computerized, centrally controlled,
irrigation system.

Benefit/Cost Analysis

The benefit/cost analyses set forth in Tables I, 2, and 3 (attached) compare three
alternative methods of calculating the City's return on its investment in the Motorola
MIR-5000 System.

Table I shows that the projected pay back period is 14.7 years if the City purchases the
System and connects. all 123 existing irrigation sites (not including any new sites in the
future - which of course is not the case) with a projected reduction in water use of 20
percent.

As shown in Table 2, the pay back period is only 5.2 years if the City purchases the
System ($46,750 including $4,000 for City furnished computer and printer) and pays for it
based on the cost of water saved (at the 1988 Park water rate of $0.88 per 1,000 gallons)
from connecting only the Arvada Center and West 80th Avenue Median (the two sites
already included in the contract price).

The Benefit:Cost ratio is 1.4 if the City considers the value of replacing the water
wasted on all irrigated sites (existing plus future) if irrigation continues as it did
-- -- - --- m-t-988-. This a.Jlaly~i::. i::. :.buwlI if.l Tc1blc J.---:-- -~------- ---- -----

Water savings from using a computerized irrigation control system have been thoroughly
studied and well documented by the California Department of Water Resources. . The
State of California has mandatory requirements for water conservation program planning
and implementation statewide. California uses a projected water savings of 25 percent
by using computerized irrigation systems. Local irrigating experience in communities
with computerized irrigation systems along the front range also support this projected
water savings. The Cities of Pueblo, Aurora, Westminster, Boulder, and Lakewood have
installed computerized irrigation systems.

Pueblo was the first to install such a system in 1986. Their Rainbird System is linked via
telephone lines to an on-site weather station to schedule irrigation periods on more than
50 park, golf course and streetscape sites. In 1986, Pueblo already had their manually
operated irrigation system fine tuned for efficient watering. However, Bob Gilliland,
Parks Superintendent, reports that since installation of the computerized irrigation
system, Pueblo has experienced an additional 21 percent reduction in irrigation water
use.

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