Laserfiche WebLink
• during July. Measured flows during the non-irrigation season ranged between 1.04 and 2.06 cfs. <br />Interestingly, the shortrecord ofdischarge measurements may suggestthatshallowground water <br />discharge into Calamity from irrigated lands provided a fairly continuous source of baseflow to <br />Calamity Draw during the non-irrigation season. Monitoring ofthis site was discontinued afterthe <br />New Horizon 2 Mine became operational. It was replaced by two surface monitoring stations SW- <br />N 108 and SW-N109. The upstream station, SW-N108 is located just west of Lincoln Street as it <br />flows from under the road. This station defines water quality and quantity before it enters the area <br />potentially influenced by the mine. SW-N 109 is located on Calamity Draw west of the mine permit <br />boundary but east ofthe Nucla waste water lagoons. This station will define the water quality and <br />quantity as it leaves the site but before it is influenced by the waste water lagoons. <br />SW-N 102 was established on a small tributary of Calamity Draw that returns irrigation tail waters <br />from irrigated fields to the main channel of Calamity Draw. Flow at this site was almost entirely <br />influenced by irrigation, although the limited discharge measurements made since July of 1986 <br />indicated that residual discharge of shallow ground water from the irrigated fields above the site <br />contributed some flow up through even January. During the irrigation period, measured flow ranged <br />from .088 cfs (October) to 2.18 cfs (August). During periods of no irrigation, flow observations <br />• made at SW-N2 ranged from zero (February, March and early April) up to .031 cfs (January). This <br />site is now being monitored as NPDES Outfall No. 007. <br />SW-N107 was located about a mile and a half below SW-N101 on Calamity Draw. Flow <br />measurements were only periodically collected at this site since July of 1986. A crest-stage gage <br />has been installed at this site for the purpose of recording high water marks of large runoff events <br />(rainfall or spring snowmelt runoff). These high water marks were used to determine the peak <br />discharge of large runoff events using indirect discharge measurement techniques. Since <br />monitoring began (July,1986), only four events were calculated using indirect techniques:1) 39 cfs, <br />11/11/86; 2) 35 cfs, 5/20/87; 3) 34 cfs, 6/22/87; and 4} 96 cfs, 8/27/87. The listed dates represent <br />the respective visit dates that high water marks were measured at the crest gage. All events likely <br />resulted from unusually intense summerthunderstorms, although no information ofthose particular <br />storms was collected. Monitoring of this site has been discontinued. <br />Finally, Site SW-N103 was located downstream of SW-N107 on Calamity Draw. Discharge was <br />measured at this site on a monthly basis since July of 1986 (see Peabody Appendix 7-5). As at the <br />ofhersites established along Calamity, flowatSW-N 103 was artificially controlled by irrigation, and <br />(Revised 6/28/01) 2.04.7-26 <br />