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• do not necessarily depend on a water table or subirrigation for <br />normal growth. However, under flood irrigation, native hay pro- <br />duction in the North Park area has the production potential of <br />1.5 to 2.5 ton/acre. <br />Based on the presence of flood irrigation and the agricultural <br />importance of native hay production in North Park the unconsolidated <br />deposits of terrace (Qt3) could therefore be classified as a <br />potential alluvial valley floor area. However, as has been pre- <br />viously stated, because this region does not lie within the Bolton <br />Draw watershed, mining will not impact the agricultural importance <br />of this area. <br />subirrigation <br />Studies concerning the potential areas of subirrigation were <br />limited to the North Fork of Bolton Draw. Certain downstream <br />• regions of main Bolton Draw are undoubtedly subirrigated to a <br />certain extent, especially immediately downstrean of the Bolton <br />Dam and stock reservoir. A determination was made concerning the <br />extent of the alluvial aquifer from the area mapped as Qal (see <br />the Map of Surficial Unconsolidated Deposits) up into the North <br />Fork of Bolton Draw. <br />A discussion of the channel characteristics up the North Fork <br />of Bolton Draw has been described previously under the discussion <br />of the nature and extent of unconsolidated deposits. Nowhere in <br />the vicinity of the channel area is there any indications of sub- <br />irrigated vegetation species except for the region mapped as unnamed <br />alluvium (Unit 8 on the soil map, Appendix E). As was previously <br />stated, this soil is composed of thick quantities of silt, has a <br />large water holding capacity and does store groundwater. The <br />evidence of subirrigation is the several clumps of willows that <br />grow in this area. <br />~J <br />-112- <br />