Laserfiche WebLink
2003 Annual Hydrologic Report Page 2 <br />• Surface Water <br />Water flow and quality on the Colorado River is monitored by the U.S. Geologic Survey <br />(USGS) at various locations. The closest location is Station No. 09095500 which is located <br />upstream approximately 7 miles north east of the mine site. Water quality and flow from <br />this site are used as a general representation of the Colorado River up gradient of the <br />mining operation. There is a diversion to the Government Highline Canal, the addition of <br />Plateau Creek and the addition of other minor drainages between the monitoring site and <br />the mine site. Data Pages SQ-34 through 36 include information supplied by USGS on this <br />site in 2003. The total flow at this site for the Year was 1,920,000 acre-feet which is 69% <br />of the normal average flow for the period 1934 -2003 (2,787,000). The estimated TDS <br />load for the Year was 1.0 million tons. This estimate is made using the values for dissolved <br />solids reported on page SQ-36 times the monthly flow in acre feet. The low flow for the <br />Year was recorded as 871 CFS on February 9, 2003. The river was carrying approximately <br />0.95 tons of TDS per acre-foot on February 9"'. This flow and TDS load equates to <br />approximately 1,641 tons of Total Dissolved Solids, TDS, being carried by the river past <br />the mine that day. The mine discharge on February 5'h (the closest monthly analysis), <br />was 265 @ 1400 mg/I TDS; resulting in approximately 2.2 tons of TDS being discharged. <br />Comparing the calculated TDS load in the River at low flow and the mine discharge near <br />the same date, the maximum increase in the River's TDS as a result of mine discharge <br />would have been 0.14%. <br />This Year's mean daily flow values for the Cottonwood and Rapid Creek flumes are <br />included on data pages SG-35, SH-26, and SI-26. Flow at SWGS-001 is presented <br />graphically on data page SG-36. As usual, the flow in these Creeks is largely controlled <br />by the City of Palisade, depending upon their need for domestic water, Also, irrigation <br />water is diverted from the creeks by private water right holders at various locations. Table <br />S03-1 was prepared to show the average monthly flows during the primary irrigation <br />season when low flow in the creeks is critical. Gaps in information are due to problems <br />with the recorder or flows below the minimum recording level of the recorder. Minimum <br />recording levels of the flumes are listed at the bottom of Table S03-1. <br />Monitoring on Coal Creek and Jerry Creek was started in 1995. The crest stage gages <br />installed in Coal Canyon drainage and Jerry Creek in 1996 were destroyed by a storm in <br />the summer of 1998. Discussions with DMG have indicated there is no need to monitor <br />the upstream locations SWGS 07 and 09. The creeks will only be monitored at the lower <br />• monitoring points. The ephemeral flow in Coal Creek is measured at culverts located <br />between the two refuse disposal areas, SWGS 06. These culverts provide a stable cross <br />