WSP07117

• File Number: 8276.130
• Description: Grand Valley Unit-Colorado River Basin Salinity Control Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 11/1/1990
• Title: Final Environmental Assessment: Price and Stubb Ditch Improvements - Grand Valley Unit
• Water Supply Pro - Doc Type: EIS

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CHAPTER II
DESCRIPTION OF ALTERNATIVES

Recommended Plan

Plan Conceots and Estimated Accomplishments

The recommended plan would consist of lining or pipe placement on 7.9 miles
of the 10-mile-long Stubb Ditch and 6.9 miles of improved lining on the
9-mile-long Price Ditch. Measures are included to compensate for wildlife
habitat loases that would result from improvement of the ditches.
Implementation of the plan would reduce salt loading by about 11,500 tons
annually at an estimated cost effectiveness of $53 per ton.

Construction is scheduled over a 3-year period starting in the spring of
1991. Construction activities would not interfere with irrigation and
would essentially be limited to the non-irrigation season.

Table 1
Estimated accomplishments
of the recommended plan

Total to Incremental
Total be lined Salt cost
length or piped reduction effectiveness
Canal system (miles) (miles) (tons/vear) is/ton)
Stubb Ditch 10.2 7.9 4,300 $52
Price Ditch ~ ~ 7,200 54
Total 19.3 14.8 11,500

Overall
cost
effectiveness
IS/tonl

$53

Plan Features

Price and stubb Ditch Improvements

General.--The canal improvements would consist of lining or piping
portions of the Price Ditch. The Stubb Ditch improvements would consist of
replacing the open channel with pipe where hydraulic conditions permit. If
hydraulic conditions prevent the use of pipe, the ditch would be lined.
Further discussion about types of improvements for the Stubb Ditch assume
that hydraulic conditions will permit pipe replacement. Major existing
structures along the canal, including siphons, flumes, check structures,
and bridges, would be evaluated as to their structural and hydraulic
soundness and would be replaced if necessary. All turnout structures would
be replaced, and new centerline check structures may be added to control
the canal water surface elevation. Existing operation and maintenance
(O&M) roads would be replaced.

Disturbed lands along the Price and stubb Ditches would be reseeded
following construction. Cover type would be selected to minimize O&M along
the improved ditches while still providing erosion control and wildlife
habitat.

Stubb Ditch.--The design flow for the Stubb Ditch would be
approximately 20 cfs. The pipe size would vary from 24 to 42 inches in

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