GENERAL53077

• Permit No: C1981041
• IBM Index Class Name: General Documents
• Doc Date: 12/1/1982
• Doc Name: Proposed Decision and Findings of Compliance
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

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Rapid Creek Alluvial Valley Floor - Findings(contid)
of ground water. The required surface water and mine water monitoring will detect
any unanticipated change in the existing hydrologic system.
3. Surface coal mining and reclamation operations would be conducted to preserve,
throughout the mining and reclamation process, the essential hydrologic functions
of the alluvial valley floor.
The essential hydrologic functions of the Rapid Creek alluvial valley floor are
those geologic, hydrologic, topographic, and soil characteristics that give the
area the ability to support flood irrigated agricultural activities. Since no
mining activities would take place within the AVF, the geologic, topographic, and "'-
soil characteristics of the AVF would be unaffected. Rapid Creek and Cottonwood
Creeks would be undermined under a limited extraction plan and mining would not
effect the surface water system that supplies the alluvial valley floor.
Colorado River Alluvial Valley Floor - Findings
1. The proposed surface coal mining operations would not interrupt, discontinue
or preclude farming on an alluvial valley floor. _
The area designated as alluvial valley floor lies outside of the permit area, down-
stream from the proposed operations. As a result, there would be no surface disturbance
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within the AVF, and the area would not be undermined.
2. The proposed surface coal mining operations would not materially damage the
quantity or quality of water in surface and underground water systems that supply
those alluvial valley floors or portions of alluvial valley floors.
Water for flood irrigated agricultural activities is obtained from two sources. The
upper terrace areas at the mouth of Rapid Creek are irrigated by flow from the Rapid
Creek system. As discussed above, mining would not affect either water quality or
quantity in the Rapid Creek/Cottonwood Creek stream system.
Agricultural activities on the lower terraces and floodplain area are flood irrigated _
with water derived from the Colorado River. Some of the Lower areas may be marginally
subirrigated by alluvial ground water. The proposed operation .would not affect the
quantity of flow in the Colorado River stream/alluvial aquifer system. Disposal of
coal refuse material in an adjacent area, and the discharge of mine water From under-
ground workings could affect water quality. The Division has assessed the possible
affects of these activities and has not identified any significant change in water
quality. -
3. Surface coal mining and reclamation operations would be conducted to preserve,
throughout the mining and reclamation process, the essential hdyrologic functions
of the alluvial valley floors.
The essential hydrologic functions of the Colorado River alluvial valley floor are
those geologic, hydrologic, topographic, and soils characteristics that give the
area the ability to support flood irrigated agricultural activities. Subirrigation
is a marginal function that is limited to a few of the lower areas which are also
capable of flood irrigation. Since no mining activities would take place within the
alluvial valley floor, the geologic, topographic, and soils characteristics of the
alluvial valley floor would be unaffected. bfining activities are expected to have
no effect on the Rapid Creek/Cottonwood Creek hydrologic system. Water quality in
the Colorado River stream/alluvial aquifer system may be slightly degraded but the
ability to flood irrigate the alluvial valley floors would not be affected.