Laserfiche WebLink
Site 2 was established just downstream of the proposed San Luis mine. Riparian vegetation <br />was very thick at this site, resulting in overgrown alders and willows covering the stream as well <br />as abundant woody debris and log dams in the channel. The substrate was dominated by sand <br />and gravel with only occasional rubble-sized rocks. The gradient was slightly less than at Site <br />], but was more uniform throughout the site. <br />~L <br />' TABLE 1: Physical parameters for Rito Seco creek, Costilla County, Colorado, <br />1988. 16-17 August <br /> <br /> Mean Mean <br />L Length width depth Flow Altitud e Gradient <br /> Statcon (m) (m) (cm) m3/sec, (cfs) (m) (%) <br />' Rito Seco creek-1 86.6 3.7 16.0 0.18 (6.4) 2682 2.9 <br /> Rito Seco creek-2 59.4 2.5 17.3 0.24 (8.5) 2612 2.4 <br /> Rito Seco creek-3 83.2 3.0 12.5 0.14 (4.9) 2521 1.6 <br /> <br />Site 3 was downstream of the entire proposed mine complex near the mouth of the canyon, <br />upstream of a gravel road crossing. There is a diversion canal just downstream of the site that <br />diverts virtually the entire creek to Salazar Reservoir. The gradient at this site was approximately <br />half that of Sites 1 and 2. Substrate was composed of cobble and gravel with sand underneath. <br />} Riparian alders and willows providing overhanging cover were abundant, but without the <br />overgrown vegetation and numerous in-channel dams observed at Site 2. Numerous active beaver <br />dams and ponds were present upstream of this site. Aquatic vegetation, including growths of <br />Ranucutus aquatilis and Veronica sp., was occasionally abundant in portions of the channel. <br />METHODS <br />Fish <br />Fish populations were sampled quantitatively at all three sites on Rito Seco creek using <br />Coffel[ backpack electrofishing gear. Sampling was conducted on 16-17 August 1988 a[ sampling <br />sites consisting of a 60-87 m (195-284 ft) measured section of stream. Each sampling section was <br />selected to be representative of the stream in the study area, taking into consideration cover, <br />pool-riffle ratio, shading, and other general habitat features. Within each study section two <br />consecutive electrofishing passes were made, and fish captured in each pass were kept separate. <br />All salmonids and non-game species captured were identified, counted, measured for length, <br />weighed and released. <br />r <br />2 <br />r~ <br />