GENERAL42857

• Permit No: C1981018
• IBM Index Class Name: General Documents
• Doc Date: 7/26/1994
• Doc Name: PROPOSED DECISION & FINDINGS OF COMPLIANCE FOR RN2
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

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Based on the demonstrated suitability of the White River Valley for imgation; the
permittee concludes that the Lind along the White River constitutes an alluvial valley
floor.
Alluvial Valley Floor Determination
On the basis of available annual water yield, the presence of unconsolidated streamhud
deposits, the availability of supplemental moisture through subirrigation, and the
presence of established irrigated lands, the Division and OSM identify the White River
and its associated alluvial deposits as an alluvial valley floor.
The permittee has supplied sufficient information to address material damages to the
White River AVF. For the most part, the White River Ges outside the permit area.
Mining will not take place beneath the river or its alluvial deposits. The permittee has
adequately demonstrated that bedrock contributions of ground water from the area to
be mined are insignificant in relation to the flows observed in the White River. Flows
to the White River from Red Wash and Scullion Gulch, which may be impacted by
mining, are also insignificant in relation to the flows observed in the White River. By
minimizing disturbances to Red Wash and Scullion Gulch during mining, the White
River will aot suffer material damage via either of these drainages.
At the time of permit issuance, Kenney Reservoir, which presently exists within the
project area, had not yet been filled. As such, the original findings document for the
Deserado Mine contained an assessment of the potential for material damage to occur
to the White River AVF as a result of the pennittces proposed pumping of water from
the AVF for use m the mine. The permittee had demonstrated that the volume of
water removed from the alluvium was insignificant to the flow volumes observed on
the White River even during low flow years, and had concluded that the effects of
drawdowa on the alluvial water body would not significantly impact farming due to the
exclusive use of artificial flood irrigation practices in the area rather than natural
sub-irrigation. This was felt to be a reasonable conclusion; however, it was also felt
that natural sub-imgation may provide additional, supplemental moisture to flood
irrigated crops. In view of this, two stipulations were attached to the permit to
provide for ongoing monitoring of the alluvial body to verify the anticipated
drawdowns caused by pumping, and to provide for the development of a mitigation
plan to protect farming operations in the event that drnwdown of the White River
alluvial aquifer had a detrimental effect on established agricultural activities. A
monitoring plan was subsequently approved and implemented, thereby resolving the
requirements of the stipulation. The approved plan called for monthly monitoring of
six alluvial wells installed within the White River alluvium above, below, and adjacent
to the alluvial well field utilized to supply water to the mining operation. At present,
only one well, Qal-5, is monitored due to the complete inundation of the remaining
wells by rising water levels from the gradual filling of Kenney Reservoir.
Stipulation No. 7 required a mitigation plan for protecting agricultural activities along
the White River. Based on the installation of Kenney Reservoir within the area
potentially affected by pumping water from the White River alluvium, the
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