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snagboat, as has been proposed, I respectfully recommend that its power, in proportion to its dimensions, be made equal to that of the ordinary river steamboats. The gain in efficiency will more than compensate for the small additional cost. A drawing of the snagboat, showing also the rake in position, accompanies the present report. The rake was used successfully on McCloskey's Bar last week, producing, with the aid of the current, a gain in depth of 2 feet in half a day's work. Below this depth was found a layer of concreted gravel which resisted the rake. It will have to be loosened with giant powder before a good low-water channel can be made here. These strata are found at many points on the Willamette, generally near low-water mark, and vary in thickness from 1 to 2 feet. STAGES OF WATER. The daily variations in the height of the river at Albany throughout the year, and at Salem since the 1st of January last. the date on which the gauge at that point was established, are shown on the profile herewith submitted. The bases of the gauges correspond to the low-water mark of 1878, the lowest on record by about 8 inches. From June 15 to October 12 the height of water varied from + 1.5 to 0.0. During the greater portion of this time navigation was suspended above Buena Vista, 13 miles below Albany. Throughout November and December the average height was 5 feet above low-water mark, a favorable stage for boating. During the first week in January the river fell to 1.3, rising again to 4.0 on the 12th, since which time it has varied from 3.0 to 22.6, the greatest height occurring on March 28, falling to 2.4 on June 30. From all indications, the low stage has fairly commenced. PRESENT CONDITION OF THE RIVER AS TO IMPROVEMENTS MADE AND DEPTH OF WATER. During the last week in June I made, as instructed, an examination of the river from Corvallis, the present head of low-water navigation, to Oregon City, for the purpose of ascertaining the condition of improvements heretofore made, and their results, and the work required to keep the river open to Corvallis through the present low-water season. Soundings were taken on all of the bars, and the following depths found : Feet . On Stewart's Bar, 111 miles from Portland 3. 9 Upper Half Moon Bar, 110 miles from Portland 4. 0 Lower Half Moon Bar, 109 1/2 miles from Portland 5. 3 Bowers's Bar, middle channel, 106 miles from Portland 3. 3 Pine Tree Bar, 101 miles from Portland 3. 8 Upper Fickel's Bar, 96 1/2 miles from Portland 4. 8 Lower Fickel's Bar, 95 miles from Portland 5. 4 Buena Vista Bar, 90 miles from Portland Portland 4.6 Long Crossing Bar, 87 miles from Portland 5. 5 Eola Bar, 73 1/2 miles from Portland 5. 4 McCloskey's Bar, 62 miles from Portland 3. 6 Lone Tree Bar, 61 miles from Portland 3. 7 Beaver Bar, 60 3/4 miles from Portland 3.7 Polalley Bar, 18 miles from Portland 6. 0 The gauge at Salem read 3.2. Observations heretofore made have shown that when the river falls at Salem, where there is very little current, from 3.0 to zero, the loss of depth on the bars varies from 1.0 to 1.2 feet in proportion to the inclination, or the velocity of the current, over each bar. It is safe, therefore, to assume that the depths above given will not be reduced more than 1.2 feet if the water should fall to zero during the present season, except at Buena Vista and Lone Tree Bars, where, as above stated, the form of the river bed is such as to cause a constant deposit of gravel on the bar during the low stage, and where raking will probably be found necessary occasionally. The dams marked (x) were all built or added to in 1877. They are in good condition, as far as could be seen at the existing height of water. Any repairs which may appear or become necessary as the season advances can be made by the crew of the snagboat. WORK FOR THE PRESENT SEASON. In addition to the removal of obstructions and raking on the bars, it will probably be necessary to build short dams at several points to assist in confining the currents to the desired channel. Such dams have been built of alternate layers of fascines and

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