WSP02948

• File Number: 8449.900
• Description: Bear Creek
• State: CO
• Basin: South Platte
• Date: 10/1/1989
• Author: McLaughlin Engineers
• Title: Engineering Report for Storable Water by CWCB's Water Rights
• Water Supply Pro - Doc Type: Publication

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Fifty percent of Morrison's winter return obligations will be stored in Bear Creek
Reservoir with the remainder being stored in other reservoirs. In actual practice,
Morrison could increase the percentage stored in Bear Creek Reservoir during a
drought cycle for the purpose of reducing the drawdown of the reservoir during the
summer.
Sewage credits will average 40 percent of the Morrison's municipal uses during the
summer.. These credits result from the use of fully consumable reservoir water.
For the years 1951, 1955, 1956, a total of75 acre-feet of its storage water will be used.
During 1954, 150 acre-feet will be required from storage for municipal uses.
To estimate the amount of Morrison's storage water in Cases No. 82CW425 and
87CW301, McLaughlin Water Engineers, Ltd:s Bear Creek water rights model will be
used. Some of the underlying assumptions of the model are as follows:

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a. All water rights formerly transferred upstream ofthe Morrison Gage, by others,
would be used fully when in priority, which would result in an instantaneous
depletion of the stream of 40 percent.
b. Exempt well depletions were not evaluated or used in the model.
c. All transfers of water rights in Bear Creek to new points of diversion and new
uses would be strictly administered according to the terms and conditions of
the decrees granted in Water Court. These water rights are used to the full
decreed amount whenever in priority.
d. Some estimates were made of possible future transfers of water rights to
municipal uses that are currently used for irrigation purposes. All water rights
currently used for irrigation of turf grasses or golf courses would continue to
be used for that purpose.
e. CWCB's Simonton ditch would divert 2.25 cis at all times whenever that much
water would be available at the Morrison Gage.
f. Return flows would be sufficient to m~et any future demands by the McBroom
Ditch.

With the above assumptions, the estimated inflows and outflows are summarized in Table A for the
1949-1957 simulated period. Note that, during some years, all of the winter return flow obligations
are released from Bear Creek Reservoir.

The assumptions of the model are conservative, and may result in less water being available to
Morrison than would be available under its augmentation plans for a similar period, especially in \n
extremely dry year such as 1954. However, for the purposes of the first cut of the Bear Creek
Reservoir Operation Study, we have not made any upward adjustment for Morrison's water rights, as
we believe such adjustment would have no significant impact on the water levels in Bear Creek

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