PERMFILE121620

• Permit No: C1989074
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: 2.04.7.2 SURFACE WATER HYDROLOGY
• Media Type: D
• Archive: No

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• (( 2.04,7.2 SURFACE VATER HYDROLOGY
III III III IIIIIII III Doc Date:12H1/2001
sss
2.04.7(2) Additional Surface Water Deta
During the additional ground water data collected from June 1988
through May 1989 there were no flows of surface water observed
and collections of eurface water data was not bs taken.
2.04.7.2.1 Topography and Drainage
Tha Rimrock Mine property is located in steep terrain dissected by numerous
drainages (Exhibit AA). The topography has been largely shaped by the
drainage patterns of the Purgatorie River. Engleville Gulch, a tributary to
the Purgatorie River, drains the Rimrock Mine area. Elevations on the
property range from about 6500 feet in the valley where Engleville Gulch flows
out of the permit area to 6900 feet in the eastern part of the property.
However, most of the lease property ranges between 6600 and 6800 feet in
elevation. The mayor topographic expression in tha area is Fisher Peak to the
south of the property.
2.04.7.2.2 Surface {Dater Quantity
2.04.7.2.2a Geomorphic Description
Engleville Gulch flows through the permit area of the Rimrock Hine and is a
tributary to the Purgatorie River. The overall drainage exhibits a dendritic
drainage pattern with the streams originating in the highlands and dropping
steeply to the river. (Exhibits CC and DD). There are no reservoirs located
along Engleville Gulch.
Engleville Gulch, an intermittent stream, has its headwaters on the northern
flank of Fishers Peak to the southeast of the mine area. The drainage drops
from an elevation of 8924 feet above mean sea level (HSL) at its headwaters to
approximately 6240 feat HSL at a point one mile downstream of the southern
permit boundary. The drainage area above this point is 3.17 square miles
(2030 acres). Drainage basin length is 24,000 feet or 4.55 miles. The main
channel length is 22,250 feet or 4.21 miles. The stream has a sinuosity of
1.06, indicating that the channel is relatively straight. The channel length
of Engleville Gulch through the permit area is 3700 feet or 0.7 miles. The
drainage area of the lease property is approximately 0.06 square miles (38
acres) or 2t of the Engleville Gulch drainage area.
2.04.7,2.2b Streamflow
Engleville Gulch is an ungaged stream. There appears to be no published data
on this tributary to the Purgatorie River. The available field data on
Engleville Gulch are limited and the quality of the data ie unknown, '
Instantaneous flow was measured at five locations (Exhibit M) during April,
1988. Methods of flow measurement depended on the amount of flow at the
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