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<br />The application includes the proposal of a monitoring program in <br />accordance with Rule 2.05.6(6)(C) to verify both mechanical and <br />geohydrologic projections. Monitoring wells are in place to <br />observe variations in both alluvial and bedrock aquifer water <br />tables. Map 2.05.6(6)(f)(ii)(c)-1, Sheet 1 of 2, delineates <br />subsidence monuments installed in the field above the underground <br />workings. Atypical monument installation is depicted on Map <br />2.05.6(6)(f)(ii)(c)-1, Sheet 2 of 2 of the application; the <br />surveyed locations, orientations, and elevations of the 12 <br />delineated structures are also provided. In addition to the <br />required monitoring structures, survey monuments and water table <br />elevations, Grand Mesa Coal Company commits to the completion of <br />photographic record of all potentially affected structures. <br />Finally, the applicant commits to the rehabilitation or <br />reconstruction of any affected structure. <br />Subsidence monitoring is currently in cessation, following approval <br />of Technical Revision 2 on January 13, 1987. The applicant has <br />committed to initiating monitoring six months prior to mining. <br />This monitoring will continue quarterly for at least two years <br />after mining into the projected area of influence. The results of <br />the subsidence monument monitoring program will be submitted to the <br />Division semi-annually. The results of the geohydrological <br />monitoring will be submitted annually following the end of the <br />water year. <br />Operations on Alluvial Vallev Floors <br />The applicant has identified several areas of unconsolidated <br />streamlaid deposits. The majority of this material occurs as <br />mudflow fans, shown as Qaf on Map 7 of the addendum. The fan <br />deposits are integrated both hydrologically and agriculturally with <br />the modern stream terraces, and should, therefore, be considered in <br />the alluvial valley floor determination. The applicant has also <br />identified four distinct river terraces south of the area which are <br />covered by alluvial mudflow deposits (see Map 7 of Volume 8). The <br />uppermost terrace (Qt4) appears to be part of a dissected pediment <br />which occupies the geographic highs between the stream valleys. <br />The remaining terraces are topographically lower, and are part of <br />the valley bottom complex. <br />Flood irrigation is very prolific in the Ward and Williams Creek <br />valleys. Eleven major irrigation ditches were identified in the <br />Ward Creek valley, and six major ditches were identified in the <br />Williams Creek valley (See Map 8 of Volume 8) In addition to the <br />main ditches identified, numerous lateral ditches exist to <br />distribute the water from the major ditches. Water for these <br />irrigation systems is provided, in part, by the Granby Ditch, which <br />transports irrigation water from reservoirs on Grand Mesa. <br />-21- <br />