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- 9 - valves were located between sections so as to allow maximum stream coverage. In general, except for increased weight, the hose-line system and installa- tion was basically similar to that previously described. However, two minor modifications were necessitated by the planned use of airboats which do not lend themselves to, ready portage. Either the hose line at the station end was sufficiently high to clear an airboat engine or the terminal end was anchored into the stream bed so as to allow a clear channel near the far bank. Secondly, each line was draped with brightly colored markers so that airboat operators could spot them from considerable distances (Figure ~-). General Treatment Plan With information supplied by U.S. Geological Survey, it was determined that the velocities of all major streams, in September, would be between 1-1~2 miles per hour, even with unseasonable water volumes. This rate estimate was verif~,ed by field observations made during the 1961 pilot study. With reasonable assurance that stream velocities would not fall below this range, it was decided, for simplicity, to plan all schedules on the basis of one mile per hour. If all stations had been placed in operation at consecutive ten-hour time intervals, the entire project treatment tine would have exceeded nine days and greatly increased many budgetary, personnel and logistic requirements. By starting stations at consecutive three-hour intervals, total time was reduced to three days, with a minimum possibility of either excessive rotenone overlap or incomplete coverage. Based on a ten-mile space interval, a three-hour starting interval, and a stream velocity of one mile per hour, a complete operational schedule was calculated for the Green River proper. From this it was possible to estimate the approximate locations of rotenone bearing waters at any given time and to coordinate the treatment of tributaries so as to provide a margin of rotenone overlap at all mainstream confluences. All mainstream dispensing sta- tions were located, and installed to conform to this schedule. The installation of station cable lines was started about one month prior to the proposed treatment date. A cable crew of four men could, with extreme effort, sometimes rig three units during daylight hours. Some sites presented special problems that greatly increased time requirements, and many hours were consumed in transporting equipment and personnel. Aerial reconnaissance and photographs indicated the presence of numerous backwaters and side channels along the entire length of the river proper. Many such areas could receive little or no rotenone from the mainstream. To assure adequate treatment of these, three airboats, (Figure 5), were scheduled to coordinate their activities with the general treatment operations. Because of their shallow draft and high speed, airboats can easily navigate river shoals and bars. Prior to the Green River treatment, airboat personnel made familiarization trips along all mainstream waters. They verified that two-man airboat crews, equipped with supplies of rotenone aril back-pack pumping units would have relatively easy access for treatment of all backwater areas on the Green and New Fork Rivers, (Figure 6).