7884

• UCREFRP Catalog Number: 7884
• Author: Hydrosphere Resource Consultants.
• Title: Reconnaissance Evaluation of Yampa River Diversion Structures.
• USFW Year: 1995.
• USFW - Doc Type: Boulder, CO.
• Copyright Material: NO

Inventory and Field Reconnaissance '
INITIAL FIELD RECONNAISSANCE I
An initial field reconnaissance of the 31 diversion structures was attempted in early
December of 1993 by a team consisting of water administration officials, civil engineers and a
fisheries biologist. The objective of this effort was to gain familiarity with diversion sites and
practices and from that information to establish the need for detailed evaluation of specific
diversion structures. Unfortunately, access problems and river ice prevented the study team
from reaching and viewing all the structures on the list (11 were actually visited). However,
the presence of local water administration officials provided an opportunity to obtain additional
detailed information about structures even if the team could not view them first-hand. This
information permitted subsequent activities to be better focused. The structures viewed in the
initial reconnaissance are noted with asterisks on Table 2-1.
One finding of this initial reconnaissance was that recorded structure names and locations
do not always correspond with local names and actual diversion locations for the same ditches.
This is partly due to the fact that state law permits irrigators to make some changes in their
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diversion locations to accommodate changes river morphology. As a result, the inventory
contained in this report may incorrectly identify or omit some structures.
This initial reconnaissance also revealed that many diversions are accomplished by
pumps situated on the riverbank or by small berms or wing dams which direct a portion of
river flow toward pump intakes or headgates. Those that involve any instream construction
activity are often built up of riverbed material and appear to wash out within a few weeks or
months. Because of their small scale and temporary nature, it is not believed that very many of
these structures are likely to present passage problems.
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Several of the larger and more permanent structures were thought to
impede fish passage. Based on the site evaluations and comments of water administration
officials, several structures were noted as warranting further study the following summer. '
These specific structures are listed in Table 2-2. In addition, it was felt that the next attempt at
field reconnaissance should be made in late July or early August when instream maintenance
work on temporary structures would be just completed and a better assessment could be made
of their potential obstruction of fish movement.
Table 2-2 ,
Structures Noted for Further Evaluation
Maybell Canal '
K. Diamond/Patrick Sweeney Ditch
Deep Cut Irrigating Ditch
Cary Ditch Co. Ditch
Shelton Ditch
Williams Irrigation Ditch

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