WSP00594

• File Number: 8200.760
• Description: Yampa River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 5/1/1976
• Author: USGS
• Title: An Environmental Assessment of Impacts of Coal Development on the Water Resources of the Yampa River Basin - Colorado and Wyoming - Phase II Work Plan
• Water Supply Pro - Doc Type: Report/Study

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is calibrated using'the collected data, it will then be used to estimate fu-
ture stream conditions for p.roJected populations and waste-treatment plant
efficiencies.

The steady-state model as described allows either: (1) Estimation of the
stream reaeration rate (K2) by using average depth and velocity relationships
for the reach, or (2) direct measurement of K2' For the YampaRiver study, K2
may be measured using a procedure developed by Rathbun, Schultz, and Stephens
(1975), This procedure uses propane or ethylene as an inert-gas tracer that
is injected at a given concentration level at an upstream location, The gas
concentration is then measured at desired stream locations below the injection
point. As noted by Rathbun, the average gas-tracer loss rate to the atmos-
phere is in di rect proportion to the average reaeratlon rate for that reach,
A. laboratory procedure for the analysis of the gas tracer (Schultz and others,
1975) has been developed,

This study would expand on the basin water-qual ity management plan made
previously by a consultant for the Colorado Department of Health as part of
the U.S. Environmental Protection Agencytsrequlrement under section 303(e) of
the Federal Water Pollution Control Amendments of 1972 (PL 92-500). The Yampa
River basin assessment will augment this previous study and will aid the U,S,
Envl ronmenta I Protection Agency in areawl de waste-treatment management stud ies
(Terry Anderson, oral commun., 1975) present Iy being conducted in the Colorado
counties of the basin.

Sediment Transport

A potent I a lly cri t I ca J Impact resul ting from st ri p-min ing of coal I s land
denudation and the transpOrt of surficial sol I material through air and water,
Secondary effects contributing to further soil eros ion include the fol lowing:

a. Canst ruct ton of roads, ra I I Ii nes, reservo i rs ,power plan ts, and
pipel ines;

b. Urban growth, such as construction of private homes, and publ icand
commercial' bu i Idings;

c. Alterations In land~use and management, Including logging, grazing,
dry-land farming, and irrigated croplands.

As the Yampa River basin Is a relatively water-deficient region, increas-
es in sediment loadings in the stream system may adversely 'affect direct uti 1-
Ization of surfa,ce-water resources. These adverse effects would extend to
onstream reservoirs and to attempts to upgrade land use in selected areas, for
example, by converting land from grazing to irrigated croplands.

Records of daily sediment concentration and load downstream of outflow
points of the Yampa River and the Little Snake River subbasins are few and of
short duration. Daily sediment records on the Green River mainstem above and
below the confluence with the Yampa River may be of Some assistance.

Both basinwide and site-specific sediment-modeiing studies are proposed
for inclusion in the basin assessment. Available models for possible appl ica-

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