WSP08927

• File Number: 8141.600.20
• Description: Fryingpan-Arkansas Project - Studies - Environmental Studies
• State: CO
• Basin: Arkansas
• Water Division: 5
• Date: 10/12/1983
• Author: US DoI BoR
• Title: Draft Supplement to the Final Environmental Statement Fryingpan-Arkansas Project Colorado
• Water Supply Pro - Doc Type: EIS

0049

3.1

'fo. "
~1 ." ,.," .

III. AFFECTED ENVIRONMENT

3.1 Introduction

Affected environment describes the current conditions of the area to b~

affected by the implementation of the alternatives:' This chapter describes

the general physical and biological conditions existing in the study area,

including hydrology, aquatic biology, wi1dlife:bio1ogy, and recreational use.

Figure 3,1 presents a generalized map of the study area. In addition, two

endangered birds, bald eagles and peregrine falcons, are included since these

populations tend to congregate around small to medium sized lakes and next to

rivers during the winter. Five species of fish listed as threatened or

endangered by the Fish and Wildlife Service or the State of Colorado are also

discussed,

.

3.2 Hydrology

The primary source of streamflow in the upper Colorado River basin is the

spring melting of the accumulated winter snowpack. The annual hydrograph (the

discharge over time) of rivers in the study area shows the highest streamflows

occurring during the late spring and early sum$er months. Stream flow is at

its lowest during the winter months. Streamflows in the Fryingpan River are

stored in Ruedi Reservoir during the peak runoff period, then released later

in the year for use in other portions of the Colorado River, Streamflows in

the Roaring Fork River are affected by diversions which transport water out of

the basin to the Arkansas River via the Frying~an-Arkansas Project. Numerous

storage and transmountain water diversion projects modify the streamflows of

the Colorado River.

Ruedi Dam and Reservoir is a major structural feature of the Fryingpan-

Arkansas project. The dam site is located 14 miles east of the Town of Basalt

in pitkin and Eagle Counties and within the White River National Forest. The

reservoir has an active conservation capacity of 101,280 acre-feet at eleva-

tion 7,766.0 feet. Surface area of the reservoir is 997 acres at elevation

7,766.0 feet. Table 3.1 gives capacity and surface area data for Ruedi

Reservoir at selected elevations.

Ruedi Reservoir provides for replacement of water diverted from the

Western Slope to the Eastern Slope and an additional regulated water supply

for other uses on the Western Slope. Maximum storage required for replacement

under the present operational conditions is es~imated at 7,200 acre-feet for

.