9344

• UCREFRP Catalog Number: 9344
• Author: Camp Dresser & McKee Inc.
• Title: Replacement of the Plateau Creek Pipeline.
• USFW Year: 1996.
• USFW - Doc Type: Denver.
• Copyright Material: NO

t

r
1

~~
I
~~

1
1

3.0 HYDROLOGIC EFFECTS
3.1 HYDROLOGIC BACKGROUND
The hydrologic effects of the replacement of the Plateau Creek Pipeline were evaluated in terms of:
1) depletions from the Colorado River Basin and 2) impacts to streamflows within the 15-mile reach
of the Colorado River. The 15-mile reach extends from the Grand Valley Canal diversion to the
confluence of the Colorado and Gunnison Rivers. Flow reductions within the 15-mile reach will be
greater than reductions below the reach. This is because most of the return flows from the Ute Water
system accrue to the Colorado River downstream of the reach while most of the diversions occur
upstream of the reach.
The primary tool for evaluating hydrologic effects was a computer model of the District's raw water
supply system developed by Camp Dresser & McKee Inc. (CDM). The model is designed to
simulate the monthly operation of the District's raw water supplies under varying demands. Using
historic hydrologic data and diversion records from the Colorado Division of Water Resources
(CI~WR), the model simulates the District's system in order to maximize the yield of the District's
water rights and storage facilities. The years 1975-1993 were selected as the period over which the
simulation is conducted. This period provides a wide range of hydrologic conditions over which to
simulate operations and it coincides with the years during which the largest collection of hydrologic
and diversion data are available.
The District's raw water is provided by a number of water rights in the Colorado River Basin which
have been adjudicated in Colorado's Division 5 Water Court. Most of these rights are located along
Plateau Creek and its tributaries, and three rights are located on the Colorado River below Plateau
Creek. In addition, the District also has two storage reservoirs in the Jerry Creek drainage (a
tributary of Plateau Creek). Many of the water rights in the District's portfolio have been developed
and are currently in use, while others are conditional rights which must still be perfected under
Colorado's water rights system. Also, within the District's portfolio are absolute rights which were
utilized for irrigation and must be adjudicated for municipal use. In modeling the operation of Ute
Water's system, it was assumed that all conditional and absolute water rights currently owned by the
District will be developed and utilized to meet demands.
3.2 BASIN DEPLETIONS
3.2.1 General
Under the Recovery Implementation Program Recovery Action Plan for the Endangered Fish
Species in the Upper Colorado River Basin (RIPRAP), proponents of new water projects which
increase depletions in the basin are required to pay depletion charges based on the net increases in
basin depletions. For Ute Water, depletions to the Colorado River Basin are a function of the net
volume of raw water diverted from the basin for use in its system, less any water which is returned
to the river from that system. The total volume diverted is a function of the demand for raw water
at the District's water treatment plant (WTP).
CDM Camp Dresser & McKee
' O:\8047-110\DOCVIPPEND-B.DOC B-2