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WATER INFORMATION h'ECE~~E~ EXHIBIT G <br />1. Surface Water General Discussion <br />DEC 112006 <br />Division of <br />1611n/nB a d <br />The site has been producing gravel since 1994, as such; most of the site consists of exposed <br />gravel. Almost the entire permit azea drains to the pit excavation, which is approximately 30 feet <br />deep. Historically, the site has been used as irrigated fields on an uplifted terrace of the <br />Uncompaghre River. Immediately east of the permit area the ground drops down rapidly for <br />approximately 25 feet to get to the lower terrace which is neazly flat to the Uncompaghre River. <br />The site is bordered on all sides by active irrigation ditches. Presently the water from these <br />ditches is being used to irrigate fields downstream. The field directly to the south of the Colona <br />Pit is not expected to affect or be affected by this operation once mining commences below the <br />water table. Increased water flow into the pit azea may occur during irrigation periods due to the <br />field to the south, but it is not expected to change drastically. <br />As shown on Maps C-1 and C-2, a siphon was installed in the north mining azea to replace a <br />surface irrigation ditch which existed on the United owned property prior to mining. This siphon <br />is 24" in diameter in a plastic Schedule 80 PVC pipe. The exit of the siphon is in the original <br />ditch on the eastern edge of the permit on the upper ten•ace which supplies water to properties <br />downstream. It has functioned for years prior to 2006 and has had no problems. The phased plan <br />for continued mining below the water table does not disrupt this pipe since it will be left in place <br />as part of the unmined berm to sepazate the two lakes. The pipe will be protected by leaving the <br />existing surface above the buried pipe for a horizontal distance of 20 feet and then sideslopes <br />will be a minimum of 3H:1 V from 5 feet below water to the surface and 2H:1 V below this level. <br />The pit is within a mile of the Uncompahgre River east of the pit. The pit's proximity to the <br />river is not expected to be an issue. The 100 yeaz flood plain does not enter the permit boundary. <br />The pit is not on the same terrace as the river, which creates a natural buffer from the floodplain. <br />Quality and flow rates for the river at this location can be found in Appendix A. <br />Colona Pit November 06 G-1 <br />