2017-02-13_REPORT - C1981041 (3)

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2016 AHR Page 3 the Year was recorded as 1110 CFS on December 28, 2015. The river was carrying approximately 0.96 tons of TDS per acre-foot on December 3, 2015, the closest data point. This flow and TDS load equates to approximately 2114 tons of Total Dissolved Solids, TDS, being carried by the river past the mine that day. The mine discharge on January 5, 2016 (the closest monthly analysis), was 273.4 gpm @ 1240 mg/I TDS; resulting in approximately 2.0 tons of TDS being discharged. Comparing the calculated TDS load in the River at low flow and the mine discharge near the same date, the maximum increase in the River's TDS as a result of mine discharge would have been 0.10%. This Year's mean daily flow values for the Cottonwood and Rapid Creek flumes are included on data pages SG -61, SH -28, and SI -28. Flow at SWGS 01 is presented graphically on data page SG -62. As usual, the flow in these Creeks is largely controlled by the City of Palisade, depending upon their need for domestic water. Also, irrigation water is diverted from the creeks by private water right holders at various locations. Table S16-1 was prepared to show the average monthly flows during the primary irrigation season when low flow in the creeks is critical. Minimum recording levels of the flumes are listed at the bottom of Table S16-1. Monitoring was suspended at these sites with the approval of TR67 on February 23, 2016. The Cottonwood and Rapid Creek flumes associated with SWGS 01, SWGS 02 and SWGS 03 were removed in August 2016. Monitoring on Coal Creek and Jerry Creek started in 1995. The crest stage gages installed in Coal Canyon drainage and Jerry Creek in 1996 were destroyed by a storm in the summer of 1998. Discussions with DRMS indicated there was no need to monitor the upstream locations SWGS 07 and 09. The creeks will only be monitored at the lower monitoring points. The ephemeral flow in Coal Creek is measured at culverts located between the two refuse disposal areas, SWGS 06. These culverts provide a stable cross section and are accessible throughout the year. The intermittent flow in Jerry Creek was measured at the culvert near the Highline Canal, SWGS 08. Beginning July 1999, instantaneous flows were monitored monthly. Data taken during the Year is listed on data page SR -4 for Coal Canyon. Monitoring was suspended for Jerry Creek (SWGS 08) with the approval of TR62 on 11/8/11. Monitoring was suspended for Coal Creek (SWGS 06) with the approval of TR67 on February 23, 2016. There were four seeps included in the hydrologic monitoring in 1995. The locations of the seeps are shown on the Hydrologic Monitoring Map. They are located adjacent to Coal Canyon drainage and Jerry Creek. They are primarily evident by the white staining on the hillsides from evaporation of the seeps. None of them flow to the creek channel but generally evaporate within a couple of hundred feet of the source. On April 19, 2006, Snowcap Coal Company submitted a technical revision, TR50, requesting to discontinue seep monitoring. The request was approved by the Division on July 25, 2006. Therefore, no monitoring was performed during the Year. There was no discharge from CDPS discharge points 005 thru 015 during the Year. These outfalls cover sediment pond discharges. Discharge point 015, now inactive, was permitted to allow pumping water from the south end of the Roadside South Portal out the 2 West portals. Discharge point 016 is permitted for gravity discharge from the northwest intake pool. It