9641 - Laserfiche WebLink

Home Browse Search

. descending limb ofthe hydrograph) and at two different spawning bars (Razorback Bar, which is on river right, and Escalante Bar on river left). Flow requests from Flaming Gorge Dam were carefully coordinated with the U. S. Bureau of Reclamation and other agencies, including those participating in the sampling, and were held at requested levels for two or more days to accommodate sampling. During that time, flow releases were adjusted based on levels of the tributary Yampa River to keep Green River flows stable and near requested targets, and flow managers should be commended for their efforts. The three releases occurred on 20,24, and 31 May, 2005 (Table 1). Orange beads were released at Razorback Bar and yellow beads at Escalante Bar. Five drift net stations were established over the entire distance of the study area for each release. Net stations were located 1.6 km downstream of Razorback Bar and at each of four different flood plain locations: Thunder Ranch (multiple inflow breaches and an outflow), Stewart Lake (outlet gate was closed in 2005 so had only one breach that acted as inflow and outflow depending on river stage), the Stirrup (a single downstream breach that acted as inflow and outflow depending on river stage), and L- 7 (a nonfunctional upstream inflow breach, and a downstream outflow breach that acted as an inflow when river elevation overtopped the breach and when flows were increasing in 2005). At sites 1.6 km downstream of release sites, nets were set at channel margins (one on the far shoreline and two on the near shoreline) and in the midchannel (one net only) for a total of four main channel nets. At flood plain sites, one drift net was set across the channel on the far river bank (relative to the flood plain inlets), one or two at mid channel depending on the site, and one in the river immediately downstream of the flood plain breaches. Two additional nets were set in the breaches. Because beads were easily observed in the drift samples, their presence was used to estimate drift rates and to determine when sampling at downstream sites should . . . . . . . . . 23 .