2015-08-31_PERMIT FILE - C1981010A ‎(23)‎

• Permit No: C1981010A
• IBM Index Class Name: Permit File
• Doc Date: 8/31/2015
• Doc Name: pages 2-346 to 2-424 ‎(2-392 to 2-401 confidential)‎
• Section_Exhibit Name: 2.7 Hydrology
• Media Type: D
• Archive: Yes

Doc Date: 12/11/2001
III IIIIIIIIIIIIIIII
999
2.7.4 Pre -mining Conditions - Surface Water
' This section describes the baseline surface -water regime in the mine -plan area
and the adjacent areas, including the Yampa and Williams Fork Rivers. Yield and
seasonality of runoff for the Yampa River valley and the permit area are dis-
cussed. Ouality of those waters is described, and characteristics of the drain-
age network in the permit area are presented. The data for the drainages in the
western portion of the area were collected prior to 1981. The eastern portion
data was collected beginning in 1984.
2.7.4.1 Water Yield and Uses
The water supplied by the Yampa River depends primarily on melting of winter
snowpacks on the high mountain slopes surrounding the valley. The lower inter-
mittent drainages produce only a small part of the total water yield of the basin
(Colorado Water Conservation Board, 1969). Walton Creek near Steamboat Springs,
Colorado, has a mean annual flow of 1.9 cubic feet per second per square mile
(Steele et al, 1979) which equals 25.8 inches of runoff. Near Craig, Colorado,
runoff was measured at less than one inch per square mile from 1914 to 1965
(Woodward Clyde, 1977). At the
2-402
X965® FEB 13 '87 ;
1
Ouantity and
quality of surface water are dependent upon a number of
interdepen-
dent variables.
Soil and vegetation types, topography, climatic
regime and
ground water
interactions are the major variables controlling the mount
of water
in a stream
at any time. These parameters are discussed in other sections. The
distribution
of flows (i.e., amount of base flow, storm flow and low
flow) deter-
mines, along
with water quality, the uses that can be made of these
waters. The
amount of water,
its seasonal distribution and the uses made of these
waters will
be discussed
for the Yampa River, Williams Fork River and drainages
of the pro-
posed permit
area.
The water supplied by the Yampa River depends primarily on melting of winter
snowpacks on the high mountain slopes surrounding the valley. The lower inter-
mittent drainages produce only a small part of the total water yield of the basin
(Colorado Water Conservation Board, 1969). Walton Creek near Steamboat Springs,
Colorado, has a mean annual flow of 1.9 cubic feet per second per square mile
(Steele et al, 1979) which equals 25.8 inches of runoff. Near Craig, Colorado,
runoff was measured at less than one inch per square mile from 1914 to 1965
(Woodward Clyde, 1977). At the
2-402
X965® FEB 13 '87 ;
1