APPENDIX Y Y. ANNUAL REPORT OF THE CALIFORNIA DÉBRIS COMMISSION FOR 1894. [Printed in House Ex. Doc. No. 11, Fifty-third Congress, third session.] OFFICE OF THE CHIEF OF ENGINEERS, Washington, D. C., December 1, 1894. SIR: I have the honor to submit the accompanying report, dated the 15th instant, of the California Débris Commission, created by the act of Congress approved March 1, 1893, entitled "An Act to create the California Débris Commission and regulate hydraulic mining in the State of California." This is the second annual report of the Commissioners, and is made conformably to the provisions of section 7 of the aforesaid act, which requires That said Commission shall submit to the Chief of Engineers, for the information of the Secretary of War, on or before the fifteenth day of November of each year, a report of its labors and transactions, with plans for the construction, completion, and preservation of the public works outlined in this act, together with estimates of the cost thereof, stating what amounts can be profitably expended thereon each year. The Secretary of War shall thereupon submit same to Congress on or before the meeting thereof. Very respectfully, your obedient servant, Hon. DANIEL S. LAMONT, Secretary of War. THOS. LINCOLN CASEY, Brig. Gen., Chief of Engineers. ANNUAL REPORT OF THE CALIFORNIA DÉBRIS COMMISSION FOR 1894. OFFICE OF THE CALIFORNIA DÉBRIS COMMISSION, San Francisco, Cal., November 15, 1894. GENERAL: The California Débris Commission has the honor to submit the following, its second annual report: The Commission was created by act of Congress approved March 1, 1893. Its members are Col. G. H. Mendell, Corps of Engineers, president; Lieut. Col. W. H. H. Benyaurd, Corps of Engineers; Maj. W. H. Heuer, Corps of Engineers, secretary. First Lieut. Cassius E. Gillette, Corps of Engineers, has been on duty with the Commission throughout the year as executive and disbursing officer and in charge of office and records. The State débris commissioner, the Hon. John F. Kidder, has been present at most of the sessions of the Commission, and has accompanied its members in visiting hydraulic mines. ENG 95-254 The jurisdiction of the Commission extends to hydraulic mining in the territory drained by the Sacramento and San Joaquin river systems in California. The duties of the Commission may be briefly summed up to be: First, the prevention of such hydraulic mining as may be deemed injurious to the navigable waters within the Commission's jurisdiction; permitting, under proper regulation, such mining in cases where it can be carried on without such injury; second, to mature general plans for the improvement of the rivers whose navigability has been injured by hydraulic mining and, if practicable, to devise general methods whereby such mining may be carried on without damage to the navigable waters. The history of hydraulic mining, as affecting the navigable waters above referred to, may be summed up as follows: The rapid washing of the large deposits of auriferous gravel, on the western slope of the Sierra Nevada Mountains, by the so-called hydraulic process, resulted in the discharging into the canyons of large quantities of gravel, sand, and other detritus, which the floods subsequently carried down, to be at first deposited largely where the streams emerged from the foothills into the level plains of the Sacramento Valley, afterwards to be moved farther down to the navigable streams and the finer portions even to tide water. The result was that near the foothills the beds of some of the streams filled up much more rapidly than their banks rose, so that their channels largely disappeared, and at flood time the streams spread over the valley lands, frequently destroying their value by covering the rich alluvium with gravel, sand, etc., often several feet deep. Long and high levees were built by the landowners to prevent as much as possible such damage. The finer particles brought down by the streams were carried into the navigable rivers, filling up the deep pools, and in general changing the character of the bed from a succession of pools and shoals to a continuous shoal. The capacities of the streams to discharge their flood waters without overflowing their banks were reduced. Legal action brought against the mine operators by persons owning damaged lands, and by the United States in the interests of navigation, resulted in injunctions against the principal mines and ultimately in the practical suppression of hydraulic mining in the region under consideration. Subsequently Congress created the Commission with the duties as heretofore outlined. (For a detailed history of the effects of hydraulic mining reference is made to House Ex. Doc. No. 98, Forty-seventh Congress, first session; also House Ex. Doc. No. 267, Fifty-first Congress, second session; and to the last annual report of the Commission.) PREVENTION OF ILLEGAL MINING. The Commission, under date of April 4, 1894, applied to the Secre tary of War for instructions as to the intent of the law in reference to hydraulic mining carried on without permits from the Commission. The opinion of the Attorney-General is appended, and marked A. In accordance therewith the Commission has given the owners of eight mines notice to cease mining. None of them have failed to obey the orders, and four of them have since made application to the Commission for permits. These mines are all small. The North Bloomfield Gravel Mining Company, which has been oper ating its mine under a decision of the United States circuit court for this district, although notified, has not applied for a permit to use the hydraulic process. The facts in the case have been referred to the Chief of Engineers, APPLICATIONS AND PERMITS. The Commission since it organized has received eighty applications to mine, of which number fifty-two have been given permits. A table showing a synopsis of the applications received and the action taken is appended, and marked B. The total amount of material mined under permits from October 1, 1893, to October 1, 1894, is estimated at 1,500,000 cubic yards. The available storage provided at present, and partially and wholly completed, for future operations, is estimated at 8,500,000 cubic yards. Comparing these figures with 38,000,000 cubic yards, estimated to have been mined in 1880, and the estimated amount of several hundred million cubic yards available to be worked, it will be seen that the system provides for the present working of only a small percentage of that possible under unrestricted mining. However, there are undoubtedly many mines which have not yet made application to the Commission, for which there is available storage as feasible as that prescribed by the Commission for other mines that are working under permits. The requirements in respect to storage of detritus exacted by the Commission vary with many conditions. Among these may be mentioned the character of the material; the river the detritus reaches; the size of the mine; its distance from navigable rivers; the output of other mines in the same drainage basin; the quantity of water flowing in that basin, and its other physical features; and the drainage through the dam site itself. If the latter is an old hydraulic pit, or a so-called flat, or a dry ravine, in which the natural flow of water is at all times very small, any type of dam that will endure while mining is carried on is considered to be efficient. In all other cases dams of a more permanent nature are required. In a small stream a gravel dam of such a height, with a spillway in rock of such a size that no water can ever go over the crest of the dam, is taken as permanent. A brush or timber dam is not considered permanent except where so situated as to be always kept wet, and such dams have in general been approved for small mines only, located at great distances from navigable streams, or on streams on which the total amount of mining is small. The Commission has not as yet issued a permit for hydraulic mining in a case where the detritus is to be stored in the beds of the larger affluents of the main rivers. The effects of freshets upon barriers in their path and in removing material stored behind barriers, even when the latter are maintained and uninjured, can be estimated best, and with least danger, in small streams. Success in these instances may justify storage in larger water courses. The Commission is feeling its way, by the light of experience, to a course of final action which shall give the greatest freedom to mining that may be found to be consistent with a due regard to other great interests intrusted to its charge. The sources of information open to the Commission are the monthly reports required of each miner holding a permit; the inspections and reports of its executive officer, and those of a civil assistant, Mr. W. B. Storey, jr., who has been employed during the working season in visiting and overseeing mining operations in Plumas and Nevada counties. These inspections and reports relate to the effectiveness of restraint of detritus, and include observations of the quantities of material escaping to the water courses. A system of observation has been developed by the use of the hydrometer, which gives in a ready manner that proportion of escaping material that can, for the purposes concerned, be regarded as soluble. This refers to the clays or to sand in exceedingly minute grains. This character of material can be stored only in cases where a period of rest can be secured behind barriers. The period of stagnation is rarely sufficient to absolutely precipitate all suspended material. To require this would in most cases be equivalent to suppression of hydraulic mining. It is the endeavor of the Commission in each case to reduce the escape to a minimum, and each case has its own solution. The Commission has not as yet adopted a minimum admissible proportion of escape which shall be applicable to all cases. Whether or not such a rule of general application shall finally be adopted is as yet uncertain. If so, it will result from a more extended experience and multiplied observations. The rivers most seriously affected by mining detritus are the Yuba and Bear. The mass of material in the lower end of the Yuba, from where it leaves the foothills to its mouth at Marysville, is so great that the present river bed is several feet above the surrounding country. It is confined by levees from 8 to 15 feet high, placed about 2 miles apart. The mass of detritus at its mouth forms a kind of submerged dam in the Feather River, so that at each high water the city of Marysville, though surrounded by high and strong levees, is seriously threatened with great danger, or even destruction. The navigability of the Feather River below the mouth of the Yuba is much impaired by this filling. Conditions similar to those of the Yuba obtain to a less degree on the Bear, another and smaller tributary of the Feather. Under these conditions a more thorough impounding of detritus is required by the Commission for mines draining into these rivers than those situated on other streams where matters are in a less serious condition. Thus somewhat less rigorous exactions are required on the American and Feather rivers and still less on the tributaries of the San Joaquin. The case of each mine has been decided on its own merits, after careful examination by the Commission, or a committee of its members. IMPROVEMENT OF RIVERS. As to the second part of the Commission's duties, the maturing of general plans for the improvement of rivers, in connection with the possible permission of hydraulic mining, the Commission has given the subject consideration, but owing to the fact that the funds available have been deemed necessary for the expenses incident to the first part of its duties, the Commission has not undertaken the surveys, which would be necessary before formulating definite plans of such scope as outlined by section 4 of the act of March 1, 1893. The Commission is in possession of numerous maps, reports of exaininations, etc., and a large amount of testimony in legal cases, affecting hydraulic mines; yet a great deal of the latter is such that, before the Commission could make definite recommendations on the general subject, much of this information would have to be checked by surveys and examinations. For example, the most elaborate estimate of the quantity of hydraulic material already mined on the Yuba and its tributaries, is that given by the testimony of the engineers for the plaintiff in the case of Woodruff v. North Bloomfield Mining Company, which total amount is set at 176,000,000 cubic yards. It is not probable that the witnesses in this case would underestimate, and yet the most reliable estimate of the amount of such material now in the Yuba, from De Guerre Point to Marysville, is 308,000,000 cubic yards. This latter estimate is based on a Government survey of the topography and a series of 35 borings through hydraulic material, the average depth of |