2013-05-16_HYDROLOGY - C1981014 - Laserfiche WebLink

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the Thompson culvert although this location is not the approved monitoring point. The important data in the record is that no flow reached the NCI monitoring point in 2012 even though considerable flow is indicated at upstream points. NEWLIN CREEK FLOW 2012 Date, 2012 Water Depth, Inches 4 -2 <1 4 -3 1.5 4 -4 2.5 4 -5 2.5 4 -5 2 4 -9 2.5 4 -12 4.5 4 -16 2.5 4 -17 1 4 -24 trickle Location Thompson culvert Thompson culvert Thompson culvert Thompson culvert NC2 Thompson culvert Thompson culvert Thompson culvert Thompson culvert Thompson culvert Est. cfs 0.8 cfs est. Averaging the water depth for the 7 days for which values are given between 4 -3 and 4 -17 and omitting the values for 4 -2 and 4 -17, gives an average water depth of 2.7 in. for 15 days. Since the Thompson culvert is a 4 ft. round culvert, the cross - sectional area is not directly proportional to water depth. At a water depth of 2.7 in. the cross - sectional area is 1.12 times greater than at a water depth of 2.5 in. Using the estimate of 0.8 cfs on 4 -5 at NC2 with 2.5 in. depth at the Thompson culvert, it may be estimated that the flow is 0.9 cfs, 1.8 acre ft. per day, or 27 acre ft. for the reported period of 4 -3 thru 4- 17, and this period does not include the DRMS inspection estimate of water flow of a considerably greater cross - sectional area on 3 -27 -2012. A very significant flow entered our property, disappeared into the ground and never left our property in 2012. According to the Annual Hydrology report the alluvial layer in Newlin Creek is very deep and wide. Since these terms of very deep and wide have no units and are fairly vague, we would suggest that a more scientific approach would be to use the drill hole information for SR27 which is about 100 ft. east of the 1' /z North Submains and about 50 ft. north of Newlin Creek. That drill log would have data about the depth of the unconsolidated layer, and the difference in elevation between the drill hole and the Newlin Creek stream could be subtracted to give a more definitive estimate of the alluvial layer. MONITORING WELLS Since the MWNW no longer can be used to monitor the presence of water in the actual mine void, it is conjecture when the blockage occurred because of the previous monitoring technique of dropping a small stone down the casing and listening for a water splash or not. With no splash the well was recorded as dry, and the stone hitting the obstruction would yield no splash. The Annual Hydrology report omits any discussion of the absolute elevation of the water levels of the other monitoring wells, of the two open drill holes SF -87 -07 and SF -87 -09 with standing water, or the place that the underground water is reappearing on the surface in Second Alkali Creek. SF -87 -07 was cased with PVC without any perforations, and it was mined through cutting off the casing at the mine roof line. The only two known openings into this casing are the top and the bottom, yet there is standing water. George