PROJ02013

• Contract/PO #: FS0071FX
• Contractor Name: New Consolidated Lower Boulder Reservoir and Ditch Company
• Contract Type: Grant
• Water District: 0
• Loan Projects - Doc Type: Feasibility Study

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In order to develop the conceptual plan and cost estimates, the above assumptions were
made to represent the "average" requirements within the service area. Although some
parks may need to be irrigated in a shorter watering window, say 8-hours, there are also
areas such as streetscapes that can be irrigated in a longer watering window, say 16
hours. Drip irrigation, because of low evaporative losses, is generally acceptable outside
of an otherwise assumed or imposed water window. Therefore, applying a watering
window of 12 hours to the entire area allows for anticipated variations from site to site.
Additionally, some turf areas will require more than 30 inches of water and some areas
will require less, so an average of 30 inches per year was applied to the overall irrigated
area.

Table 1 summarizes the assumptions made to determine water requirements for the
irrigated areas served by this system.

Table 1. Water Use Assumptions

DESCRIPTION OF ASSUMPTION

UNITS VALUE
% 80
0/0 25
in 12
0/0 80
in/day 0.29
% 80
in 30

Proposed Irrigation System Application Efficiency
Effective Precipitation Ratio
Seasonal Precipitation
Tap Utilization Efficiency
Peak Season Reference ET
Crop Coefficient For Bluegrass
Seasonal Irrigation Requirement For Bluegrass

LANDSCAPE AREAS
BLUEGRASS

ft2
acre

98,925,155
2,271

Table 2 shows the water use calculations for the total irrigated area within the Lower
Boulder service area. The total required flow rate to irrigate 2,270 acres within a 12-hour
watering window is approximately 31,050 GPM during peak season.

Aqua Engineering, Inc.
June 2004

Canal Modernization Feasibility Study
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