WSP00576

• File Number: 8449.900
• Description: Bear Creek
• State: CO
• Basin: South Platte
• Date: 1/1/1991
• Author: Batchley Assoc.
• Title: Bear Creek Operational Study - Vol. 2 - Appendices Part I
• Water Supply Pro - Doc Type: Publication

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Arnett/Harriman Ditch
Ward Canal

Churn Ditch

Our research revealed South Platte River calls were almost
always junior to Bear Creek calls and were of no consequence
relating to historic calls for ditch rights studied.

Bear Creek Call Threshold - Diversion records for Bear Creek do
not always indicate demand by a water right of its full
entitlement. This is particularly evident in the spring or
fall, and may be attributable to (a) sufficient precipitation
available to meet crop requirements, (b) cold weather, (c)
inoperative headgates, or (d) adequate soil moisture.

Future water demand will likely be more consistent than that
which occurred in the past as water use on Bear Creek changes
from agricultural to municipal. In order to reflect this, we
developed monthly "flow thresholds" from the generated call
records. A flow threshold is the minimum streamflow deemed
necessary at the Morrison gauge for a particular water right to
be in priority. We conservatively set the thresholds so that .
they generally enveloped plots of call versus streamflow because~
the relationships between streamflow and generated calls were ~
not always consistent.

Water Riqht Yields - The yield of the Genesee water rights
lncluded in the study were computed on a daily basis from the
generated calls and recorded streamflow at Horrison. A water
right was assumed to be in priority and allowed to divert if (a)
its priority date corresponded to, or was senior to. the
generated call, or (b) the flow at Morrison was greater than the
flow threshold for that month. Decretal provisions regarding
rate of diversion and historical season of use were included in
our study.

Water Available for Storaqe - In order to estimate the quantity
of water available for storage by Genesee under its Pioneer-
Union Priority Nos. 11 and 15, it was necessary to subtract
Genesee's direct flow water needs from the computed yields of
its water rights. The portion of Genesee's pioneer-Union No. 11
and 15 rights not required for direct flow purposes was assumed
available for storage. Direct flow water requirements were
estimated by extrapolating current water use to that expected at
full buildout. The district currently serves approximately 1.100
Equivalent Residential Units (EQR) and is expected to serve
about 1,613 EQR's in the future. Estimated average monthly

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