Estimate of probable cost of removing the rocks. Sawyer's Rapid: Wages of 10 men, 6 days each, at $3. Wages of 1 blacksmith and helper, at $8 Wages of 1 overseer, at $5 ... Tools for drilling: 10 drills, 10 hammers 1 portable forge. 1 ton coal 50 pounds giant-powder, at $1 50 Transportation of men and material Total... Hart's Rapid: Transportation of 13 men and material, Sawyer to Hart.... Wages of 10 men 18 days, at $3. Wages of 1 blacksmith and helper, at $8. Wages of overseer, 18 days, at $5.. 3 tons coal, at $20. 200 pounds giant-powder, at $1 50. Total. $180 00 48 00 30 00 40 00 50 00 20 00 75.00 60 00 503 00 $26 00 540 00 144 00 90 00 60 00 300 00 1,160 00 This amount is in gold coin; $22,549 33 in currency, at 90 cents. As a steamboat can certainly carry freight, with improved navigation, from Roseburgh to Scottsburgh at $20 (coin) per ton, the difference or amount saved on imports of the valley alone, for less than one year, will more than pay for the removal of obstruction to the navigation of the river. It is therefore to the interests of the steamboat company as well as to those of the valley to remove the rocks. Very respectfully, your obedient servant, R. S. WILLIAMSON, Major of Engineers. Brigadier General A. A. HUMPHREYS, W 5. SAN FRANCISCO, January 28, 1871. GENERAL: I have the honor to transmit herewith a report of the survey made under my direction by Lieutenant W. H. Heuer, United States Engineers, of portions of the Sacramento River. The one is of that portion between Rio Vista and the foot of Steamboat Slough; and the other between Sacramento City and Haycock Shoal. The two maps accompanying this report illustrate the character of the river in the parts surveyed. The intermediate portions of the river contain no obstacle to navigation worth mentioning. The surveys demonstrate that there is 7 feet of water, at the lowest stage of the river, over the most difficult bars, and as it is believed that the amount of freight received on board the boats does not reach the amount necessary to bring them to draw 7 feet of water, there is no real obstacle to the navigation of the river in its present condition. Nevertheless, it appears that there are three points on the river, viz, at Eagle's Nest, Haycock Shoals, and near Sutterville, where, if the river could be deepened without forming shoals elsewhere, it would result that at least 8 feet of water can be carried from Sacramento City to the mouth of the river. It has been shown that the river cannot be improved by dredging. The effect of wing-daming is uncertain, for though in some cases the effect of them has been decidedly beneficial, in other cases bars have been formed which were detrimental to their navigation. I think, however, that the experiment is well worth trying; and I Brigadier General A. A. HUMPHREYS, SAN FRANCISCO, CALIFORNIA, January 28, 1871. MAJOR: In accordance with your order of October 19, 1870, directing me to make a survey of that portion of the Sacramento and Heacock's River between Sacramento and Heacock's Shoals, together with a survey of that part of the river containing the Hog's Back, I started with my party for Sacramento on the following day and there commenced operations, gradually working down the river to below Heacock's Shoals, nine and three-quarter miles below Sacramento. The field-work of this section of the survey was completed on November 4, in twelve working days. We then moved camp to near the Hog's Back obstruction, (about thirty-nine miles below Sacramento,) and made a survey extending from the upper end of the slough containing this obstruction to the head of Gillespie or Wood Island, near the town of Rio Vista, a distance of seven miles. This portion of the survey was completed November 19. The average width of the river between Sacramento and Heacock's Shoal is about 700 feet, its greatest width is 750 feet, and it is narrowest about one and a half miles below Sacramento, where it is only 275 feet wide. Between Sacramento and Heacock's Shoals the river makes several bends, at each of which the river narrows to about one-half its average width; just above and within 200 yards of the contraction is where the shoals are found. The least depth of water on these shoals, in the channel, is 7 feet, but in the bends we found from 20 to 30 feet depth of water. After leaving the bends the water becomes less deep, averaging about 10 feet. Some of the river men attribute the formation of these shoals to the placer mining which was carried on in the streams emptying into the Sacramento. Immense quantities of débris would thus be carried down stream and deposited here and there along the bottom of the river. The deposit or shoal is a mixture of sand and mud, the particles of which were probably held in suspension by the water, and were gradually carried down stream by the force of the current until they reached nearly to these narrow places near the bends, where the velocity of the current was checked and caused the sediment to deposit. The banks of the river are generally clay, (adobe,) covered with a rich soil, except on the convex side of the bends of the river; there the bank is invariably sand. The banks vary in height from 5 to 25 feet, beyond which the ground is comparatively level for a distance of from twenty to thirty miles, when the country becomes hilly. At Sacramento the mean observed rise and fall of the tides is about nine inches. The tide gradually increases as we proceed down the river. The extreme observed tide of Hog's Back (thirty-nine miles down the river) was 4 feet. At Chicory Ranch (four and a half miles below Sacramento) a few current observations were made. It was found that at half-ebb tide the velocity of the surface current was 108 feet per minute, while at half flood the current was 100 feet per minute, thus showing that this far up the river the tides affected the current but little. At the Hog's Back, however, a very different result obtains. There, during a flood tide, the current runs up stream two-thirds as rapidly as it flows down during an ebb tide. From this it would be inferrred that there must be some point between Hog's Back and Sacramento where the tide ceases to produce an up-stream current, and that at or near such place a shoal or bar might be expected. On conversing with the steamboat men on the subject, I found that there were several shoals in that part of the river, but that they did not interfere with its navigation. This is probably due to the fact that after we get above the Hog's Back the river is very much narrower than below, the current being more concentrated, and therefore stronger, would have a tendency to scour away deposits left by the flood tide. About eight miles above the upper end of the Hog's Back the Sacramento River forks. One of these branches is called Steamboat Slough, which is six miles long and not over 200 feet wide, opening at its lower extremity into the slough containing the Hog's Back, which suddenly widens from 200 feet to 600 feet, and in some places to 900 feet in width. The other fork is the Sacramento River proper, and is called Old River. It is wider, shoaler, and larger than the slough. For this reason steamboats do not navigate it. The difference between extreme high and low water of the Sacramento River, at Sacramento, is 24 feet. The highest known flood of the river occurred in January, 1862, when the river over flowed its banks and presented the appearance of a lake fifty miles in width. To pro'tect the banks from overflow levees have been built along its banks, varying from 3 to 10 feet in height. Near the mouth of the river the floods do not reach nearly so high. The highest observed water-mark was but 12 feet above its low-water stage. The water of the river is very muddy, which is probably due to the mining on some of its forks. Steamboat men state that fifteen or twenty years ago the water was very clear, and that, at present, it is not so muddy as it was ten years ago; this is also attributed to the decline of placer mining. At Sacramento the river, at low-water stage. is 30.5 feet above the level of the sea, (deduced from a long series of barometric observations by Dr. Logan, of Sacramento.) Its fall is not definitely known, but is supposed to be about 5 inches per mile. The time of transmittal of the tidal wave from San Francisco to Sacramento (one hundred and twelve miles) is 9.2 hours. In that portion of the river between Sacramento and Heacock's Shoals a channel is found 8 feet deep and 75 feet wide in its narrowest part, with the exception of but one place, which is two and three-fourths miles below Sacramento, or about threefifths of a mile above Sutterville; here a bar is found 600 feet across, having only 7 feet depth of water over it, (shown on the map and marked section on E. F.) After leaving this bar we find good water, but the channel again narrows to 75 feet in a bend of the river, near the Chicory Ranch, four and a half miles below Sacramento, after leaving which we again have a good, wide channel, until we arrive at the wing-dam at Heacock's Shoals; here, again, the channel contracts to about 75 feet in width, but it is crooked. A channel 7 feet deep and 100 feet wide is found from Sacramento to below Heacock's Shoals. The narrow and crooked channel at this shoal can probably be improved by repairing the wing-dam there. The estimated cost of the repairs is $845. About Suttersville the shoal might be improved by throwing in a wing-dam 700 feet long from the left bank. As the water immediately above and below the proposed wing-dam is only from 9 to 10 feet deep, it is to be feared that the sand, which the dam would cause the current to scour out, would be deposited below, and perhaps form a new bar equally as bad as the one now found. That portion of the river containing the Hog's Back varies in width from 500 to 900 feet. The Hog's Back is not a well-defined single bar, but it is a series of shoals, having 7 to 8 feet depth of water between. The distance from the upper to the lower of these shoals is about three and one-half miles. A channel 7 feet deep and 75 feet wide in its narrowest part is found over these shoals. The average width of the 7-foot channel is 200 feet. There is but one of these shoals that contains as little as 7 feet depth of water; it is know as Eagle's Nest, and is 400 feet across. Each of the other shoals have 8 feet of water over them. The bar at Eagle's Nest can be improved, if necessary, by building a wing-dam 50) feet long from the opposite side of the river, starting near the wood-yard. DESCRIPTION AND EFFECT OF THE WING-DAMS CONSTRUCTED IN THE SACRAMENTO Of the wing-dams constructed by the California Steam Navigation Company three yet remain; one at Heacock's Shoals, 400 feet long; one at the upper end of Hog's Back Shoal, 400 feet long; and the other one and one-half miles below, which is 1,500 feet long. They are built by driving two parallel rows of piles; rows 6 feet apart, the piles in each row varying from 6 to 8 feet from center to center. The general direction of the dams is diagonally across the current. Between the piles, willow bushes, their butts up stream, are placed and thrown in until the top of the brush is at the level of high tide; they are then kept in place by pieces of board nailed over them, and extending from pile to pile. The general effect of the wing-dams has been to benefit the navigation over any particular shoal in which they were placed. Before the long wing-dam was built on the Hog's Back boats frequently grounded there, but now that the current has been concentrated a channel 10 feet deep has been made over the worst of the bars. A great portion of the sand washed out was deposited close to the down-stream side of the dam, and has formed a bare bar 1,600 feet long by 250 feet wide. DREDGING. Some efforts have been made to improve the navigation of the river at Hog's Back by dredging. Several thousand cubic yards of sand and mud were removed, but as soon as the river began to rise a little the channel which had been dredged out refilled to its old level. The experiment demonstrated that the river could not be improved by dredging. The steamboats that navigate the Sacramento River are all owned by the California Steam Navigation Company, and are magnificent boats. Numerous sailing vessels also ply between San Francisco and Sacramento. Sailing vessels frequently ground in making the trip, but that is probably due to their inability to keep in the channel. Steamboats do not run aground often. They carry all the freight that offers, and could carry much more than they do during the lowest stage of the river. The president of the company informed me that their boats could carry 600 tons of freight on 7 feet depth of water. To what extent commerce would be benefited by increasing the depth of water by a foot or two in that portion of the river mentioned in this report I cannot say. To increase the depth, so that vessels drawing more than feet of water could navigate the river during its lowest stage, numerous places between Sacramento and Rio Vista would require improvement at an enormous expense. Wing-dams might improve the navigation in several places, but it is feared that their good effects would be counterbalanced by shoals which they would cause lower down the river. For all the present demands of commerce the depth of water in the Sacramento River is sufficient. The following is an estimate of the cost of a wing-dam 500 feet long near Eagle's Nest: Cost of 128 piles, 30 feet long, at 25 cents per foot.. Transportation of same from San Francisco to Hog's Back. Driving 128 piles, at $5 each.. Labor on dam, thirty men ten days, at $2 50 per day. Total cost...... This would make the cost about $5 45 per linear foot. A wing-dam 700 feet long near Sutterville would therefore cost. Repairing old dam at Heacock's shoals.. $960 00 128 00 640 00 750 00 247 80 2,725 80 Add for proposed dam at Eagle's Nest.. $3,815 00 845 00 2,725 80 Would make a total cost of improving the river at these three localities... 7,385 80 The result of the survey is embodied in the two maps which accompany this report. Very respectfully, your obedient servant, W. H. HEUER, Lieutenant of Engineers." W 6. SAN FRANCISCO, July 21, 1871. GENERAL: The third section of the act of March 3, 1871, making appropriations for river and harbor improvements, directs an examination or survey at Santa Cruz, California, and by the direction of the Chief of Engineers this work was placed in my charge. On making inquiries upon this subject, I find that by an act of the legislature of the State of California approved February 11, 1870, a commission was appointed "to examine the harbor of Santa Cruz and Salinas Slough, in the bay of Monterey, for the purpose of ascertaining whether the same or either of them are or can be made suitable for a harbor of refuge, and whether the same or either of them can, by artificial means, be improved." A copy of the report of this commission is hereby appended. Without going into a discussion of the details of the commissioners' report, it is very apparent that to improve the harbor of Santa Cruz with a view of making it a harbor of refuge, a breakwater similar to the one described by them must be built, and the cost of such a structure will be several millions of dollars. |