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Inventory and Field Reconnaissance SECOND FIELD RECONNAISSANCE A second round of field reconnaissance was carried out in August of 1994. This time period was chosen in the belief that it would permit a more thorough evaluation of the extent of instream construction activities associated with temporary structures and because it would permit observation of late-summer hydraulic conditions at the diversion structures. The reconnaissance began with an overflight of the river from Cross Mountain Canyon up to the vicinity of Mt. Harris. The objectives of this overflight were to obtain a more comprehensive view of the number and types of mainstem diversion structures, to identify any problematical structures that had been omitted from the previous inventories, and to obtain a more accurate description of structure locations. Notes and photographs were taken during the ' overflight and ditch location information was recorded directly onto a set of 7.5' maps of the reach. 1 1 The overflight was followed up by three days of site visits to the individual structures previously identified (in Table 2-2 above) as being problematical as well as several others that, for reasons of proximity to previously identified structures or concerns raised during the aerial reconnaissance, were deemed important to see first hand. As a result, between the two field reconnaissance efforts, 15 diversion structures were examined first-hand. The structures visited in the second field reconnaissance are listed in Table 2-3. Table 2-3 Structures Visited in Second Field Reconnaissance Maybell Canal K. Diamond/Patrick Sweeney Ditch Craig Water Supply Pipeline Deep Cut Irrigating Ditch Cary Ditch Co. Ditch Shelton Ditch Williams Irrigation Ditch Marshall Roberts Ditch A checklist was used to organize the observations made at each of these sites. While not all items on the checklist were relevant at each site, the list served as a reminder to record whatever observations were possible pertaining to the following: • location vis-a-vis critical/occupied habitat • physical characteristics of the diversion structure • apparent permanence of structure • soils and geology at the site • effects on upstream and downstream river morphology • water surface elevations and flow velocities • local ecological disturbance (instream and riparian) • construction access and materials available 2-5