APPCOR10867

• Permit No: C1984065
• IBM Index Class Name: Application Correspondence
• Doc Date: 10/26/1984
• Doc Name: RESPONSE TO DRAFT FINDINGS & STIPULATIONS
• From: STORM KING MINES
• To: MLRD
• Media Type: D
• Archive: No

Basin deep beneath the surface of the earth. The minimum cover
remaining at the crown pillar of the workings will never be less
than 200 feet of undisturbed rock and/or coal. The 5-year extent
of mining would extend 200 feet below an unnamed ephemeral
channel in the NW1/4,SW1/4, Section 10, T6S, R90W. in that
vicinity, a ventilation shaft and an escapeway will be extended
to the surface. The surface drainage area of the ephemeral
channel is about 60 acres in this vicinity. The 60 acre area is
a very small fraction (less than 0.48) of the total South Canyon
Creek Basin, estimated to be about 25 square miles. No impact is
expected on South Canyon Creek from the advancement of
underground mining into the Basin. Even at the 25-year extent of
mining, no underground workings will extend under the main
channel of South Canyon Creek. Because no interaction with
surface hydrology is anticipated, no monitoring program is
proposed for South Canyon Creek.
B) MLRD is requiring that more flow quantity data be reported in
the Permit Application for the Colorado River. Storm King Mines
currently collects monthly field parameters and quarterly water
quality samples. The large flow and size of the Colorado River
makes measuring or estimating the flow rate difficult. Flow
estimates for the Colorado River are based upon the U.S.
Geological Survey's gaging station located below Glenwood
Springs, after the Colorado River's confluence with the Roaring
Fork River. The USGS data is reliable but there is a time delay
between recording of river state (height of the water above some
datum) and the reduction of that data to flow rate (cubic feet
per second). Preliminary data reductions for the gaging station
through December 1983 have been obtained and analyzed. Mean
daily Colorado River flows on the dates that Storm King collected
field or water quality samples during the January through March
1984 period are also available. Based upon the preliminary USGS
data, a revised Appendix 3.3-12 table of field measurements,
including discharge, for the Colorado River in the vicinity of
the Storm King site has been prepared. Annual Colorado River
hydrographs for water years 1983 and 1984, through July 1984, are
included in Appendix 3.3-12. Flows were higher than normal in
1983 with the annual runoff about 50$ higher than the mean annual
runoff of 3,250 cubic feet per second. Statistics for 1984 are
not yet available but it appears that it was another high runoff
year.
Flow in the Colorado River varies from a base discharge of about
2,000 cfs during much of the interval of September through March
of each year. Suspended material is low during this time of the
year. Conductivity, an indicator of dissolved material, is
generally in the range of 700 to 1,000 umhos/cm. Increased flows
commence in April or May with annual peaks in the range of 20,000
cfs typical from the snowmelt that often peaks in mid to late