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

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EXECUTIVE SUMMARY
As part of the Upper Colorado River Endangered Fish Recovery Program, fish passage
is proposed at the Hartland diversion dam to provide fish access to historic habitat further
upstream on the Gunnison River. The target species for this projeCt include the Colorado
pikeminnow and the razorback sucker. Selective passage for the screening of non-native
predators is not considered necessary at the Hartland Diversion Dam since selective passage is
provided on the Gunnison River at the Redlands fish passageway downstream at Grand
Junction, Colorado.
Three alternatives are developed and presented in this report. These alternatives
include a concrete fish ladder on the east bank, an open channel boulder drop-pool fish ladder
on the east bank and the reconstruction of the dam for fish and boater passage in an open
channel drop-pool sequence through the center of the river.
Both Alternatives I and II (concrete or boulder drop-pool on east bank) accomplish the
goal of providing fish passage and both alternatives are relatively inexpensive. However, the
City of Delta has expressed an interest in the third alternative, which provides fish passage and
accommodates boater passage. Alternative III is more expensive than either Alternative I and II
since it requires regrading 250 feet of river, installation of concrete cutoff walls and over 20,000
tons of boulders. The primary advantage of Alternative III is that it opens this reach of the
Gunnison River to boater passage, which is currently not possible due to the height of the
Hartland dam. Hartland Irrigation Company was not opposed to Alternative III.
The three alternatives are evaluated for a range of hydraulic conditions ranging from low
flows of 350 cfs up to and including the 100-year flood of 21,200 cfs. Bank overtopping for
existing conditions and all three alternatives occurs when flows .exceed 11,600 cfs, the 5-year
event. For events that exceed 11,600 cfs the dam becomes submerged and the difference in
water surface elevations upstream and downstream of the dam become small enough that fish

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