Laserfiche WebLink
<br />localized. Grilling and groundwater monitoring activities on the 19t. <br />Gunnison Permit area confirm that groundwater and associated aquifers <br />within the permit area are of limited extent. Subsidence has the . <br />potential to impa~:t groundwater aquifers at>ove the F seam. Springs _ <br />associated with these aquifers may be affected. While subsidence <br />fractures may dry up some springs, it is also likely that new springs <br />may form or some inay~increase in flow as fracture patterns expand <br />their recharge areas. Some surface water or groundwater may also seep <br />into the mine as ,i result of subsidence fracturing. The amount of <br />mine water inflow: is got expected to be large. 14ine inflows in any <br />given area are de~~endent on the proximity of water bearing sandstone <br />units in the overlwrden to the mine zone and the extent of hydrologic <br />connection with these units due to natural pre-existing fractures, and <br />fractures resulting from the mining operation. It is expected that <br />impacts of subsid~ance on groundwater or surface water will be tem- <br />porary as fractur~as seal in response to subsidence in adjacent areas <br />or expansion of swelling clays. <br />Springs below the F seam should not be affected by mining unless they <br />derive their water from sources located above the F seam. Only <br />springs above the F seam coal are likely to be affected. Because of <br />the intermittent character of springs on the permit area, subsidence <br />impacts on springs flows will not significzntly affect water supplies <br />during the "critical need" periods. In fact, the potential for <br />improving conditions (delaying snowmelt runoff) is as likely as is a <br />negative impact. An intensive stream flow monitoring and analysis <br />program will asse::s these impacts. <br />Of greater concern far water supply during "critical need" period:> is <br />the Deep Creek dil:ch water which poses through the permit area within <br />the Dry Fork channel. Dry Fork water is the only flow through the <br />lease block that c:an be stored for use during "critical need" periods. <br />Thus, only the wager in Dry Fork can be considered capturable. The <br />percentage of capturable water would be larger in dry years becau:s2 <br />the amount of wat~:r that can be stored in ,vet years is limited by the <br />capacity of ~~tinne:~ota Reservoir. The state engineer has saacified that <br />(6) <br />