PROJ00441

• Contract/PO #: C153459
• Contractor Name: Loveland, City of
• Water District: 0
• County: Larimer
• Bill Number: XB 99-999
• Loan Projects - Doc Type: Feasibility Study

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As shown in Figure 5-1, the CBT project derives water from several streams
in the Upper Colorado River Basin. Determination of the runoff from the
contributing watershed cannot be measured directly due to the lack of
appropriately located streamflow gauging stations. Direct measurements of
total inflow to CBT are not available; however, these values can be derived
from other data collected by the NCWCD and USGS on a regular basis as
explained below.

Water balance equations were developed to represent the various inflows to
and outflows from the three major storage facilities in the Colorado River
Basin. By combining these equations, the monthly inflow to the CBT system
can be defined as:

CBTINF(n) = CBTSTOR(n) - CBTSTOR(n-1) + CBTFF(n) +
CBTSPILL(n) + GSEEP(n) + ADAM(n)

(Equation 5-1)

where CBTINF(n)

= total inflow to the three reservoirs in month n;

CBTSTOR(n)

total end-of-month storage in Villow Creek, Shadow
Mountain, and Granby in month n;

CBTFF(n)

= total fish flow releases from Villow Creek and
Granby in month n;

CBTSPILL(n)

= total spill or release from Villow Creek and Granby
in month n;

GSEEP(n)
ADAM(n)

= seepage loss in month n; and

= delivery to Adams Tunnel in month n.

The six variables on the right side of equation 5-1 are known or can be
calculated. End-of-month storage contents and Adams Tunnel diversions are
available from the USGS. The combined fish flow release requirements for
Willow Creek and Granby are (BUREC 1984):

5-4