WSP05450

• File Number: 8220.114.I
• Description: Dolores Participating Project
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 2/1/1995
• Author: USDOI-BOR
• Title: Draft Environmental Assessment - Proposal to Modify Operation of McPhee Reservoir and Acquire Additional Water for Fish and Wildlife Purposes
• Water Supply Pro - Doc Type: EIS

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CHAPTER III
AFFECTED ENVIRONMENT
AND ENVIRONMENTAL CONSEQUENCES

A.' INTRODUCTION

Descriptions of the sire and selling of McPhee ReselVoir and the Dolores River downstream from
McPhee Dam are contained in the Final Environmental Statement (lNT FES 77-12) and Definite Plan Report for
the Dolores Project (Reclamation 1977), the Fish and Wildlife Analysis for the Dolores Water Project (CDOW,
1974), the Dolores River Wild and Scenic River Study Report (Depts. of Agriculture and Interior, Colo. Dept. of
Nat. Resources, 1976), the Draft Plan cf Study for the Dolores Project Resources Optimization Study
(Reclamation 1990), the Dolores River Corridor Management Plan (BLM, 1990), the Dolores River Instream
Flow Assessment Project Report (BLM, 1990), and the Dolores River Native Fish Habitat Suitability Study
(Bio/West, Inc., 1992). The areas or resources potentially affected by the proposed action and alternatives are
generally confmed to the river channel and floodplain of the Dolores River downstream from McPhee Dam.
Emphasis has been placed on the first 12.2 miles of the river downstream from McPhee Darn to the Bradfield
Bridge vicinity because this river reach was intended to support a cold water sport fishety in the original
DPRlFES. This chapter addresses in detail the significant environmental issues/resources described in Chapter I
potentially affected by the proposed action and alternatives. Other issues or resources are also briefly described.

B. AQUATIC RESOURCES

1. AFFECTED ENVIRONMENT -The aquatic resources potentially affected by the proposed actioa
are primarily those associated wirh the Dolores River downstream from McPhee Dam. McPhee ReselVoir would
not be appreciably affected hy changes in downstream release parrerns and therefore the aquatic resources in the
reservoir would not be significantly impacted. Described below is a summary of the significant existing aquatic
resources affected by the proposed action and alternatives.

TROUT F1SHERY

The tailwater trout fishery in the Dolores River downstream of McPhee Dam was established soon after
the dam was closed in 1984. Reclamation's FES identified a twelve mile section of the Dolores River
immediately downstream of McPhee Dam, which would provide suitable habitat for the development of a good
quality cold water (trout) fishery. This section of river was initially stocked by the Colorado Division of
Wildlife (CDOW) in 1984 with fingerlings of the following trout species:

Brown (Salmo truna)
Cutthroat (Salmo clarki)
Rainbow (Oncorhvnchus mvkiss).

While some successful natural reproduction does occur by these species, principally ftom brown trout, natural
reproduction is supplemented by the annual stocking of fmgerling trout. Also, concurrent with the establishment
of the fishery, the CDOW restricted angling methods within the quality Irout 5ection to fly fishing and artificial
lure only and disallowed Ihe keeping of fish by designating the 12 mile reach as a catch-and.release fishery.

l3ased on commitments made in the FES and DPR, three flows would be released through the dam for
Ihc purpose of creating and sustaining a trout fishery, based on relative water supply. These flows were 20 cfs,
50 cfs and 78 cfs in dry, average and wet yean, respectively. ror purposes of comparison, these flows would
release 14,480, 36,200 and 56,470 Ar, respectivcly, per year to the Dolores River. These volumes do nOllake

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