Laserfiche WebLink
1 <br />' flat area with the deposition of mud, silt and sand at high reservoir levels. As a result, alluvial <br />groundwater monitoring holes Dal-1, Dal-2, Dal-3, Dal-4 and Dal-6 have been destroyed and are <br />no longer available for monitoring. Alluvial hole Dal-5 is still being monitored. <br />During May 1987, longwall panel 1 was mined past the location of 2-12U. The location was <br />subsided and the monitoring hole could no longer provide usable data. Accordingly, Western Fuels <br />' submitted an application for a Technical Revision on 6/7/88 to eliminate groundwater monitoring at <br />2-12U. The Technical Revision has subsequently been approved. <br />' 2.2 Summary and Analysts of Deserado Mlne Hydrology Data <br />Data collected during this water year (October 1, 1992 to September 30, 1993) have been <br />' summarized and compared with the data from the baseline hydrology inventory. Surface water and <br />ground water discussions are presented separately in the following sections. <br />' 2.2.1 Surface Water Data Surface water data has been collected from four (4) stations in the <br />Deserado Mine area. The locations of these stations are shown on Plate 1 in the pocket of this <br />' report. With the exception of the White River, stream flow in the Deserado Mine area is ephemeral <br />with flows occurring only in response to rapid snow melt or during heavy thunderstorms. Gaging <br />' stream flow and collecting water samples is therefore dependent upon being able to collect samples <br />and gauge flow while the flow event is occurring. Heavy thunderstorms can result in flash floods <br />which destroy the sampling and gauging stations. Station SW24-1 has been destroyed twice, the <br />' last time in the Spring of 1983. Up until July 1986, this station was a 'grab sample° location where <br />samples were taken as soon as possible after significant thunderstorms and during snow melt run <br />' off. Anew single stage sampler was installed in July 1986. Other stations have been plagued with <br />problems such as the samplers silting in and the gauging apparatus silting in. These problems are <br />corrected as soon as possible but there is no guarantee that the next flow event will not also plug <br />' the sampling and gauging apparatus. <br />The data collected from the surface water monitoring program during the hydrology reporting year <br />is contained in Appendix B. The statistical summary of the data is also included in Appendix B. <br />These data are compared with the original baseline data to determine if changes have occurred. <br />The baseline data is reported in the 'Deserado Mine First Annual Hydrology Report", 1985 as well <br />as in the permit itself. <br />' As during the previous reporting period, stream flows were rare, due to the low incidence of <br />thunderstorms which cause run off events. The snow melt run off caused flows detected at three <br />' monitoring stations in March and April 1993, The northwestern Colorado region continues to be the <br />most severely affected portion of the State by the drought of recent years. <br /> <br />5 <br />1 <br />