2004-12-07_PERMIT FILE - C1984063

• Permit No: C1984063
• IBM Index Class Name: Permit File
• Doc Date: 12/7/2004
• Section_Exhibit Name: Rule 2.04 Environmental Resources
• Media Type: D
• Archive: No

• Surface Water. The permit area lies within the Upper Main
Stem of the upper Colorado River Region CBLM 1y72>. The
main drainages in the area are Rifle Creek, East Rifle
CreeK, West Elk Creek, Main Elk CreeK, and East Elk CreeK.
The Rifle CreeK drainages, located to the west of the permit
area flow into the Colorado River near Rifle, C.olarado. The
Elk Creek drainages which lie to the north and east of the
permit area flow into the Colorado River at New Gastle,
Colorado. The permit area is drained by six small ephemeral
drainages and ohe perennial drainage. These seven drainages
enter the Colorado River approximately three and one-half
miles south of the permit area (see Figure 11: Drainage
Patterns of the Easide Mine Permit and Ad~iacent Areas). The
elevation of the tributaries range from about 7,700 feet at
their headwaters to about 5,400 feet at their confluence
with the Colorado River.
The headwaters of each drainage are along the Grand Hogback.
Hillslopes and stream gradients in the headwater areas are
very steep and drainage patterns are well developed. Soils
are rocKy and rock outcrops abound. Vegetation is generally
of a pinyon-,juniper type. Understory vegetation is scarce
and rill and gullies are common. Stream channels are
scoured to bedrock in many locations. Between the Hogback
and the Colorado River, slopes flatten considerably and
watershed boundaries are not well defined. Naturally
occuring vegetation is primarily composed of sagebrush and
grasses. Much of this area is used extensively for
agricultural purposes. Each of the ephemeral drainages is
intercepted by one or more irrigation ditches before it
reaches the Colorado River. Stream gradient profiles of
several of the intermitent tributaries are shown in Figure
12: Stream Gradient Profile.
The six ephemeral drainages are unnamed. Streamflow is
seasonal, occuring in response to snowmelt or precipitation
events. These drainages are unaffected by diversions or
man-made developments. The seventh drainage, Harvey Gap, is
greatly influenced by irrigation releases and seepage from
Grass Valley Reservoir. The Harvey Gap drainage remains
perennial due to seepage from Grass Valley Reservoir.
Grass Valley Reservoir, 5,800 acre-foot capacity, is a.
component of the Sitt Project. The Silt Project provides
water for the irrigation of almost 6,000 acres of land ire
the Silt and Rifle Area. The reservoir is located near the
head of the drainage. Water transferred from East Rifle
CreeK is stored in the reservoir. The Silt Project is
operated pursuant to a three part contract between the
Bureau of Reclamation, the Silt Water Conservancy Distrir_t
and the Farmers Irrigation Company.
47 Revised 5.%'$?