WSP02105

• File Number: 8200.765
• Description: White River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 5/1/1986
• Author: Morrison-Knudsen
• Title: White River Geotechnical Study - Final Report - Volume I
• Water Supply Pro - Doc Type: Report/Study

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001104

WHITE RIVER GEOTECHNICAL STUDY
FINAL REPORT
EXECUTIVE SUMMARY

The 1983 session of the Colorado General Assembly passed House Bill 1102,
authorizing the Colorado Water Conservation Board (CWC8) to conduct a
geotechnical study of dam sites in the White River Basin. Specifically, the
bill called for studying sites located at Powell Park, Lake Avery and two
si tes between the confl uence of the North Fork and South Fork of the Whi te
Ri ver and the Hi ghl and Ditch Headgate. In May of 1985, the CWCB contracted
with Morrison-Knudsen Engineers, Inc. (MKE) to perform the study.

The objective of the White River Geotechnical Study was to carry out surficial
and sub-surface geotechnical investigations of the designated dam sites, and
to locate and evaluate potential sources of construction material. The level
of topographic data on the reservoir areas was to be upgraded. In addition,
appraisal-level designs and cost estimates of various alternative dam
confi gurati ons were to be made, based on the fi ndi ngs of the geotechnical
investigation, as well as technical and economic comparisons of the sites.

The study was initiated by reviewing available reference material from
previously completed geological and water development studies carried out in
the White River Basin. A network of targets for air photogrammetry were set
and tied in to existing survey control. Aerial photographs were taken of the
potential reservoir areas and topographic maps at a scale of one inch to 500
feet, with 10-foot contours were prepared. Aerial photography was also flown
for each dam site and topographi c maps at a scal e of one inch to 100 feet,
with 5-foot contours were prepared.

Field work started with general surficial geologic mapping of the study area.
The primary objective was to define the principal structural features and
lithologic units in the region. In addition, reservoir permeability and slope
stability of the potential reservoirs were evaluated. Borrow areas for
potential construction materials were also located during the surficial
mapping program.