WSP04021

• File Number: 8062
• Description: Federal Reserved Water Rights
• State: CO
• Basin: Statewide
• Date: 9/1/1979
• Author: R Barry Nehring
• Title: Evaluation of Instream Flow Methods and Determination of Water Quantity Needs for Streams in the State of Colorado - September 1979
• Water Supply Pro - Doc Type: Report/Study

42

Cost/Benefit Analysis

Bovee and Milhous (1978) concluded that the cost of three
sets of data is small compared to the cost of one set which may
prove unreliable. My results (Tables 17 - 19) show that the cost
of data collection was almost directly proportional to the number
of times the study reach was visited and the travel distance to
the study area. Furthermore, travel time and per diem costs were
as much as five times the cost of on-stream data collection time.

Recommendations for Methodology Application in Colorado

Since 1974, the Colorado DOW, working in close association
with the Colorado Water Conservation Board (hereafter CWCB),
has acquired 40 water decrees on streams throughout the State.
Another 467 applications for water rights under S.B. 97 have
been ruled upon favorably by the CWCB, and 100 applications are
presently pending with no action taken to date. These filings
are the result of the field efforts and office work of up to 20
employees of the Colorado DOW on either a part-time or full-time
basis.

During the past year this investigator carried out an
incre~ental method of analysis on 15 streams and 18 stream
reaches. The recommendations for minimum flows on these 18
reaches would affect a maximum of 190 stream miles.

There are reportedly (Colorado Division of Game, Fish, and
Parks, 1970) 14,700 miles of streams in Colorado. In light of
the above stream mileage in Colorado, the absolute enormity of
the task of completing even a single transect on the fishable
streams (reported to be 8,000 miles) becomes overwhelming.

The contract states, "Monthly water quantity needs for fish
and wildlife populations will be recommended for all "critical"
stream reaches on which adequate historical discharge records
are available plus those streams on which methodologies are
tested. Water quantity needs will be presented for low and median
water year conditions, and for high water year conditions (i.e.,
waterfowl nesting) if applicable." Making monthly recommendations
would be no more than a mathematical exercise completed to fulfill
to the letter the stipulations of this contract. The CWCB has
worked closely with and has been generally sympathetic to the
recommendations of the Colorado DOW in the past. In my opinion,
if every stream flow recommendation was to be presented as a
month by month flow request all progress henceforth would cease.
Even if the CWCB ruled favorably on the month by month recommenda-
tion, the ruling would be unenforceable and totally ignored.

From
have been
request.

a realistic
made on the
The October

standpoint, minimum flow recommendations
basis of an April through September fIOW
through March flow is generally somewhat