Economic Analysis of Critical Habitat Designation in the Colorado River Basin for the Razorback Sucker, Humpback Chub, Colorado Squawfish, and Bonytail April 1994

• Description: Economic Analysis of Critical Habitat Designation in the Colorado River Basin for the Razorback Sucker, Humpback Chub, Colorado Squawfish, and Bonytail April 1994
• State: CO
• Basin: Colorado Mainstem
• Date: 4/1/1994
• Title: Economic Analysis of Critical Habitat Designation in the Colorado River Basin for the Razorback Sucker, Humpback Chub, Colorado Squafish, and Bonytail April 1994
• Water Supply Pro - Doc Type: Report/Study

The current conditions were determined by examining a historical set of flows for the years
1967 through 1985 at 10 United States Geological Survey (USGS) gaging stations. Next,
flows for recovery of the fishes were projected as well as depletions for future activities with
and without endangered fishes. These projections took into account both listing and critical
habitat designations. An illustration of the hydrograph for one gaging station (Colorado
River at Cisco, Utah) is shown in Figure I -5 -1. The details of this analysis are available in
Chapter II -6 of Brookshire et al. (1993).
The hydrologic analysis formed the basis for the "without fish" and the "with fish" scenarios.
There are four hydrologic scenarios and these can be discussed in the context of Figure
I -5 -1:
1. Current depletions without any actions taken on behalf of the
endangered fishes (the dotted line in row 1 of the figure);
2. Current depletions but with actions taken on behalf of the endangered
fishes (the dashed line in row 1 of the figure);
3. Future depletions to be allowed without considerations of the
requirements of the endangered fishes (dotted line in row 2 of the
figure);
4. Future depletions taking into account the requirements of the
endangered fishes (dashed line in row 2 of the figure).
The solid lines represent USFWS identified flow levels believed necessary for recovery of
the endangered fishes after being modified to be compatible with outputs of the Colorado
River System Simulation model. A critical element of the economic analysis involved
determining the economic impacts in the study region due to changes in the river flows as
required for recovery of the endangered fishes. This involved assessing the impacts of
revised operating plans of the dam system on recreation, hydroelectric generation,
agriculture, municipal, and. industrial water uses.
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