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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Task 3 - Obtain Site Access: Make all necessa~ arrangements to obtain
access to private and public property for the purpose of geologic mapping and
where indicated, subsurface investigation.

Task 4 - Geologic Mapping: Prepare surficial geologic maps at two scales.
The fi rst coveri ng the enti re project area i ncl udi ng all damsi tes and poten-
tial reservoir areas. The prima~ objective being to define the principal
structural features and lithologic units in the project area. The second
scale map was to be a detailed surficial geologic map of each damsite
descri bi ng in more detai 1 than the areal mappi ng, the condi ti on of the soi 1
and exposed bedrock outcrops, weatheri ng, and j oi nti ng patterns that mi ght
affect the stability and permeability of the dam foundations.

Task 5 - Reservoir Area Evaluation: Evaluate the permeability and slope
stability of the potential reservoirs based on the surficial geologic mapping
with special attention to the area of landslides along the south side of the
river near Warner Point.

Task 6 - Foundation Investi gation: Car~ out subsurface i nvesti gati ons at
each damsite selected, utilizing a combination of backhoe pits, auger holes,
cased and cored rota~ borings, and seismic refraction surveys. Obtain undis-
turbed samples of the foundation materials for laboratory testing and perform
borehol e penetrati on and penneabil i ty tests in the foundati on soi 1 and water
pressure tests in the foundati on rock. Log and photograph all test pi ts,
samples, and core.

Task 7 - Construction Materials Investigation: Conduct a thorough recon-
naissance of available construction materials at each damsite selected.
Investi gate the quanti ty and qual i ty of the materi al s by means of auger hol es
and back hoe pits, and obtain samples for laboratory testing.

Task 8 - Laboratory Testing: Perform laboratory tests on soil and rock
samples obtained from the dam foundations and potential borrow areas to deter-
mi ne thei r physi cal characteri sties, strength parameters, and sui tabil i ty for
use in the proposed dams.

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