9593

• UCREFRP Catalog Number: 9593
• Author: Tetra Tech Inc.
• Title: Concept Development Report Hartland Diversion Dam Fish Passage Structure Delta, Colorado.
• USFW Year: 2000.
• USFW - Doc Type: Grand Junction, CO.
• Copyright Material: NO

TABLE 7.2 SUMMARY OF HYDRAULIC PARAMETERS FOR FISH PASSAGE ALTERNATIVES

River Flow (cfs) 350 650 1200 3000 3460 6470 11600
average average
exceeded low flow exceeded
90% in over 50% in yearly 1 .25-yr 2-yr event 5-yr event
Description Aug & July period of August pre-runoff event
record flow
Flow in
Ladder 20 21 23 28 29 29 29
(cfs)
Aux. 43 42 41 40 39 . 34 28
Flow(cfs)
Alt Total 63 63 64 68 68 63 57
I Flow(cfs)
Ladder 3.3 3.6 4.1 5.1 5.3 6.5 8.1
Depth (ft)
Ladder
Velocity 3.0 2.9 2.8 2.8 2.7 2.3 1.8
(ftIs)
Flow in
Ladder 49 50 63 75 7S* 7S* 75*
(cfs)
Aux. 43 42 41 40 39 34 28
Flow(cfs)
Alt Aux. 92 92 104 114 109 104
II Flow(cfs) 11S
Ladder 3.3 3.6 4.1 5.0 5.0* S.O* S.O*
Depth (ft)
Ladder
Velocity 3.0 2.8 2.7 2.7 2.7 2.7 2.7
(ftIs)
Flow in 3S0 650 1200 3000 3460 6470 11600
River (cfs)
Alt Depth (ft) 1.7 - 4.5 2.1 - 5.0 2.6 -S.S ..* ..* ..* ..*
III
Velocity I 4.7-0.7 I
4.6 - 0.4 4.8-1.1 *** *** *** *** I
(ftIs)

* River flows entering ladder are limited with forebay gates.
** Flows overtop banks and inundate ladder. Fish passage possible along river banks.
*** Fish passage possible along river banks.

7.1.1 Alternatives I and II

The HEC-RAS results indicate that unc;1er proposed conditions for Alternatives I and II

the water level is lower than under existing conditions by less than 0.1 foot for all flows

analyzed. When flows in the Gunnison River drop to 350 cfs, the lowest flow analyzed, the

drop in water surface elevation due to the ladder and attractive flows, is 0.07 feet. At 3000 cfs

33

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I