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

0058

3.10

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Large conditional rights on the Colorado River are located between Glen-

wood Springs and the Grand Valley. These rights are for municipal, domestic,

and industrial purposes, primarily related to the oil shale industry. The

largest 12 conditional rights held by the oil shale industry total about

831,100 acre-feet per year (1,150 cfs). Numerous studies have been made to

determine the future water demand of the Colorado River as it relates to oil

shale development. The estimated degree of development of conditional rights

which would take place in response to domestic and industrial growth varies

from less than five percent for a very limited growth scenario to 65 percent

with very large-scale growth (Rice et al., 1982, and Colorado Department of

Natural Resources, 1981). With approximately one-half of the conditional

rights being developed in the future, an increased demand of 433,600 acre-feet

per year (600 cfs) would result. This level of demand was assumed to be a

conservative level for future demand for the Ruedi Reservoir operational stu-

dies. Information on the frequency and magnitude of Colorado River water

shortages for present demand and future demand levels is given in Table 3.5.

Based on the requests for water from Ruedi Reservoir, about 20 percent of

the demand will be for municipal and domestic purposes. The remaining

requests represent future water demand by the oil shale industry of about

347,000 acre-feet per year (480 cfs). This corresponds to an oil shale

industry size of between 1.4 million and 2.1 million barrels per day based on

current water use estimates for this industry.

Demand patterns given by municipalities requesting water show that the

demand for water will vary over the year for municipal and domestic use.

These patterns were used to develop a weighted municipal and domestic water

demand pattern. Industrial demand was assumed to be constant during the year.

Table 3.6 shows the demand patterns which were used in scheduling water

releases from Ruedi Reservoir.

3.3 Aquatic Biology

3.3.1 Physical/Chemical Characteristics and Habitat Features

A brief discussion of the physical and chemical characteristics of Ruedi

Reservoir is provided below. The reservoir, which is aligned in an east-west

direction, is about five miles in length, 0.2 to 0.8 miles in width, and has a

full surface area of 997 acres. The volume of the reservoir is usually at or

just below maximum capacity of '102,400 acre-feet in the summer, while minimum