WSP00031

• File Number: 8200.776
• Description: Uncompahgre River General
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 1/1/1972
• Author: DOI-BLM
• Title: Uncompahgre Project Colorado - Special Report on Need for Improvement and Extension
• Water Supply Pro - Doc Type: Report/Study

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CHAPTER I

INTRODUCTION

of 12 feet. For approximately half of its length from its beginning
at the diversion from the Gunnison River, the tunnel waS constructed
in sound crystalline rock and is unlined. For the remaining half of
its length, the tunnel was constructed in the Mancos shale formation
where concrete lining was installed for stability purposes. Little
rehabilitation work has been necessary in the initial half of the
tunnel but the lining in various reachea of the latter half has
cracked, bulged and otherwise deteriorated. Due to frequent surveil-
lance followed by any necessary repair work, no major failures of
the tunnel lining have occurred.

The project includes a total of seven major diversion dams, one
on the Gunnison River at the head of Gunnison Tunnel, and the remain-
ing six on the Uncompahgre River at the heads of the Montrose and
Delta, Loutzenhizer, Selig, Ironstone, East and Garnet Canals. The
diversion dams for the Montrose and Delta, Selig, and Ironstone Canals
are constructed of concrete except for steel gates in the canal head-
works and river control sections. The remaining major diversion dams
are partially of timber construction.

The South Canal receives its water directly from the Gunnison
Tunnel, and, except for winter stock water diversions, water for West
Canal is conveyed from South Canal by a flume across the Uncompahgre
River. A small temporary dam is constructed each fall using stream-
bed materials to divert stock water from the Uncompahgre River into
West Canal. Other minor diversion structures are located at points
where flows of small streams of the area are taken into the canal
and lateral system. The largest of these structures is located where
the Hontrose and Delta Canal diven:s from Coal Creek.

With exception of South and West Canals, the locations for the
project water distribution system were essentially established prior
to authorization of the project. Some of the canals and laterals
include reaches with steep gradients and nUmerous points of abrupt
drops in elevation. Chutes or other types of drop structures have
been constructed at most of the points of abrupt elevation drop but
at some locations no drop structures have been provided. The amount
of erosion that has occurred at these latter locations varies with
the amount of water conveyed, the gradient through the drops, and
the types of lnaterials in the drop areas. A reach of the Hontrose
and Delta Canal about 4~ miles in length consists of the natural
channel of Coal Creek. Although some erosion of the channel has
occurred in the past, riprap has been placed at numerous locations
to protect against erosion and the channel is now well stabilized.

Combined lengths of the project canals and laterals as originally
constructed total about 568 miles. Hinor changes in alignment and
abandonment of terminal portions of a few of the laterals have reduced
the combined lengths of the distribution system to a current total of
about 565 miles. Additional data concerning lengths and capacities
of the canals and laterals are shown in the tabulation on page 11.

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