always be given an opportunity to express their views concerning desired improvements.

279.3. Examination by reporting officer.—A personal examination of the waterway to be reported on must be made by the officer preparing the report. Quotations may be made from previous reports. The new reports should not be simply a restatement of facts and opinions formerly presented but should be based upon a new investigation and careful reconsideration. The report should contain all the facts necessary to the formation of an opinion as to the worthiness of the improvement not only by the reporting engineer but by others who may not be entirely familiar with the locality and the attendant circumstances. The facts should be presented in such complete form as will enable the Division Engineer to reach a proper decision, and in such form as to show that the recommendations made rest upon a substantial basis.

279.4. Estimates in separate letter. (a) Estimates of cost of surveys will not be included in preliminary examination reports but will be submitted by accompanying separate letter in which will be given the estimated cost of survey, whether recommended or not, the length of time which it is expected will be required, detailed information in regard to the character and extent of the data to be obtained, and the method to be employed in making the survey.

(b) No project or plan of improvement or estimate of cost thereof should be presented in the report of preliminary examination except in a general way. In preliminary examinations or reviews thereof any statement of estimated cost must be given in such terms as "a large (or small) sum," "a million dollars or more," "many million dollars," etc. A specific figure, no matter how broadly conditioned, is likely to be taken as a definite commitment of the Department and used as a criticism if the final figure developed based on definite plans and detailed information is at any considerable variance therefrom. However, if the preliminary examination is made under the provisions of the Flood Control Act approved March 1, 1917, an estimate of the cost of the survey will be contained in the body of the report.

(c) As knowledge of the approximate cost and economic status of an improvement is of great value to the reviewing authorities in passing upon a report, the preliminary examination report, whether favorable or unfavorable, will be accompanied by a separate letter in which shall be given as close an estimate of the cost of the improvement discussed in the report, and an estimate of the probable annual charges and the annual benefits, as the available data will permit. This information should be included in the letter in which is given the estimate of the cost of survey.

(d) The estimates, in separate letter, pertaining to preliminary examination reports on flood control should show the estimated cost of each feature of improvement discussed, including amortization in a period of not more than 50 years, and the cost per acre protected assuming the entire cost were levied against the protected area. A rough estimate should also be given to the probable additional total cost and cost per acre of drainage, pumping, and other auxiliary works if required.

279.5. Sketch maps.-Preliminary examination reports will be accompanied by such outline or sketch maps as can be prepared at small expense, utilizing existing available data or data which can be readily procured. They should show definitely the examination area, major political subdivisions, all cities, towns or other features mentioned in the report including main line railroads, and coordinates of latitude and longitude.

279.6. Photographs.-Carefully chosen photographic views have proven of material assistance to reviewing authorities in arriving at a clear understanding

of the locality. The submission of one or more typical photographic views with reports is permissible. The number of photographic views in reports shall, however, be restricted.

279.7. One report covering requirements of two acts.-When an authorization provides for a report of a locality before a report already called for by a previous act or resolution has been submitted, one report only need be made, but it should state distinctly that it covers the requirements of both authorizations. 279.8. Time within which to submit reports.-Reports will be submitted without unnecessary delay and reports of preliminary examinations shall in every case be submitted within a year from the date of assignment, unless in the opinion of the district officer the circumstances are such as to render this impracticable in which case the reasons shall be stated to the Chief of Engineers and request made for authority to delay.

279.9. Object and scope of reports.-The object of the preliminary examination is to determine whether or not the existing conditions and facts warrant the expenditure of funds for a survey. The object of the survey is to determine whether or not an improvement is economically justified. When the preliminary examination indicates that there is a reasonable possibility that an improvement may be economically justified a favorable recommendation for a survey is warranted. The instructions contained herein for the preparation of reports are given to secure complete and orderly arrangement of the data and pertinent facts. In some cases it will be necessary to include additional material in support of the conclusions and recommendations of the reporting officer. In general, the reports on preliminary examinations should treat the various subjects as briefly as possible, and for their preparation costly field work and research should be carried on to a very limited extent. On the other hand, it is very necessary that sufficient data and facts be furnished to give a clear understanding of the conditions involved and also to show the reasons for the views and recommendations of the reporting officer. The reports on survey should contain the latest information available on the various subjects, and facts and data must be obtained by sufficient field work and office study to permit the preparation of reliable estimates of cost of construction, prospective annual benefits, and other information which has a bearing on the justification for improvement.

279.10. Surveys under House Document No. 308, Sixty-ninth Congress, First Session, and Section 10 of the Flood Control Act approved May 15, 1928.-Surveys for navigation, flood control, power, and irrigation, called for by the River and Harbor Act approved January 21, 1927, in accordance with House Document No. 308, Sixty-ninth Congress, First Session, and Section 10 of the Flood Control Act approved May 15, 1928, and supplemental studies pertaining thereto, as authorized in Section 6 of the River and Harbor Act approved August 30, 1935, will be prepared in accordance with the instructions governing the preparation of preliminary examinations and surveys, in so far as they are applicable. No studies under the provisions of Section 6 should be placed under way without securing prior definite approval from the Chief of Engineers.

279.11. Appendices.—In the preparation of reports where important features of a proposed project involve extended computations, compilations, and analyses of basic supporting data, such as geologic, hydrologic, and meteorologic records, and detailed cost and benefit estimates pertaining to items discussed in the report, which from their nature and volume are not required or appropriate for inclusion in the report proper, these data should be assembled and submitted as appendices to the report. The text of appendices shall be prepared on the size of sheet specified for "Manuscript,” paragraph 286.

PRELIMINARY EXAMINATIONS, NAVIGATION

280. Form and order of report. The report on preliminary examination shall contain the following subject matter in the order stated, in form and style to be easily readable and understandable even by those not familiar with Department procedure. Subheadings should conform to those given below, but headings should be omitted where there is nothing to report. Thus, if no bridges cross the waterway, insert a sentence so stating in the paragraph headed "Description." If no prior reports have been made and no project for improvement adopted, so state in a similar manner. If the matter included under any heading is extensive, it should be suitably paragraphed for convenient reference. Thus the heading, "Commerce," may be subdivided into "Commerce-resources," "Commerce-past and present," "Commerce-prospective." Paragraphs will be numbered consecutively without reference to headings.

280.1. Authority.-Cite the authorization for the examination and quote verbatim the item of law or the Committee resolution covering the report being made. Subject to prior approval by the Chief of Engineers, reports may be made to cover more than one authorization. In such cases, specific reference will be made to such approval and to each item of authorization.

280.2. Description.-Give a general description of the waterway or harbor with reference, in proper cases, to adjacent harbors or waterways. For rivers, include the geographical description of the watershed to which the waterway belongs, the drainage area, the low water, mean stage and high water conditions, the magnitude and extent of tidal effect, the average controlling depths over the bars, the periods during which the different stages prevail with particular reference to the periods when peak traffic movements occur, and the average, maximum and minimum discharges. For harbors, give depths, tidal or other fluctuations of water surface, exposures, etc. Describe briefly connecting channels and their navigable capacity. This paragraph should give a clear picture of the navigable capacity of the waterway. Give reference to published charts of the locality and to maps submitted with the report.

280.3. Tributary area. Give a comprehensive description of the immediate locality and the tributary area, including extent and character, cities and towns, population, resources, industries, roads, and railroads. Where resources and industries give rise to a large volume of rail or waterway traffic, describe in a general way the commodities produced and how they are transported at the present time.

280.4. Bridges.-List the bridges crossing the portion of the waterway under consideration, giving location and clearances, type of movable span, railway or highway, ownership, date built, and whether or not constructed under permit. If the improvement proposed entails the alteration of bridges, the general nature of the alterations shall be stated.

280.5. Prior reports.-Describe the prior reports on the waterway, giving the document numbers of printed reports, or the dates of unprinted reports, and the recommendations made. If many prior reports have been made, the information may be listed in tabular form. In general, it will be sufficient to refer only to reports made within recent years.

280.6. Existing project.-Give a brief history of the Federal improvement prior to the existing project, an exact statement of the existing project, and a clear statement of the status of completion of the existing project. Give the total cost for new work and for maintenance of the project, and the present approved annual maintenance cost. In proper cases, discuss the adequacy of the esti

mated maintenance cost. If the average actual cost of maintenance during the last 5 years is materially different from the estimated annual maintenance cost, explain briefly the reason therefor. Describe any changes in the existing project that have been recommended to Congress but not authorized, citing the report or document.

280.7. Local cooperation.-Describe the improvements made or work done by local interests under prescribed conditions of local cooperation, and give a statement of the amounts contributed in cash toward Federal improvements. State what rights-of-way, easements, disposal areas, etc., have been furnished.

280.8. Other improvements.-Describe navigation improvements made by local interests other than those that have been made under prescribed conditions of local cooperation, and state the cost if obtainable. Include improvements by state or local interests to immediately tributary waterways which benefit the commerce on the waterway being reported upon.

280.9. Terminal and transfer facilities.-The report should show what exists and, in a general way, what is needed in the way of harbors, slips or basins, wharf or pier areas, and available frontages of wharves, docks, or piers, under municipal and other public control, to permit full utilization of the water routes improved by the United States and to give them their maximum efficiency. Such information should show briefly the wharves or docks of public ownership, their connection with rail and water lines of transportation, and whether their use is open to all on equal terms or is restricted or is discriminatory. Similar information should be stated with regard to private wharves. Freight-handling facilities at existing wharves should be briefly described. The space available for terminals, but not utilized, should be stated, and if necessary, described. 280.10. Improvement desired.-State the improvements desired by local interests and by whom proposed. If a public hearing has been held, give place, date, and character of attendance. Give reasons advanced in justification for improvements desired. Where improvements are urged by responsible interests, other proposals made by uninformed parties and clearly not justified may be disregarded or briefly touched upon. State any local cooperation offered.

280.11. Commerce.-A full and careful study should be made of all obtainable facts and data in regard to the present and prospective demands of commerce involved in the proposed improvement including its amount, nature, and value. Commerce should be given in short tons of 2,000 pounds, and data and discussions should be included as follows:

(a) Statistics for as long a period as is available and pertinent, listing the principal items;

(b) Discussion on the trend as shown by the statistics;

(c) Estimate of the prospective commerce and transportation savings if improvement is made;

(d) The use of the waterway by seasonal passenger craft, yachts, houseboats, fishingboats, motorboats, and other similar watercraft, whether or not operated for hire. (See Public, No. 16, 72d Congress, approved February 10, 1932.)

280.12. Vessel traffic.-Give the number, character, size, and draft of vessels now using the waterway, with any pertinent discussion thereof as related to existing navigation facilities or improvements desired.

280.13. Difficulties attending navigation.-Describe any unusual difficulties to navigation that now exist.

280.14. Water power and other special subjects.—In making investigations for the improvement of rivers for navigation consideration shall be given to the possibility and desirability for developing a coordinated plan embodying improvements for water power, flood control, municipal and industrial water

supply, abatement of pollution, irrigation, wild life, recreation, and any other purpose which involves the control and conservation of the water resources. The treatment of these special topics should be limited to procuring information of a general character. The development of a coordinated plan which will ultimately provide the greatest overall benefits to the region as a whole should be left for the survey.

280.15. Shore line changes.-Every report submitted looking to the improvement of the entrance at the mouth of any river or at any inlet shall contain information concerning the configuration of the shore line and the probable effect thereon that may be expected to result from the improvement having particular reference to erosion or accretion for a distance of not less than ten miles on either side of the entrance. (See Section 5 of the River and Harbor Act, approved August 30, 1935). Whenever studies in connection with a preliminary examination or a review thereof indicate that the proposed improvement merits serious consideration and that detailed investigation of the probable effect on the adjacent shore lines is warranted, the Division Engineer on the special board to which the investigation has been assigned will secure by direct correspondence the advice of the Shore Protection Board on the nature, scope, and cost of such investigation. The report of the Board will be transmitted with the letter accompanying the preliminary examination report in which the cost of a survey is stated.

280.16. Discussion.-Under this heading summarize the arguments and data presented by local interests or secured as a result of the examination. Discuss briefly the findings of the reporting officer, including information relative to the amount and character of commerce existing or reasonably prospective which will be benefited by the improvement; the probable relation of the cost of the improvement to the total benefits; the public necessity for the work; the probable extent of local benefits, the reasons why local cooperation may be required; and any other matters of importance that have a bearing on the conclusions and recommendations of the District Engineer.

280.17. Conclusions.-State conclusions as to the advisability and justification for improvement, Indicate the character and extent of improvement if any, considered advisable. State what local cooperation if any, should be required and the probability of its being furnished.

280.18. Recommendation.—The report will conclude with a recommendation that a survey and estimate of cost be made, stating clearly the scope and character; or with a statement that the locality is not regarded as worthy of improvement by the United States at this time and a recommendation that no survey be made.

280.19. Report of the Division Engineer. The report of the Division Engineer will be in the form of an indorsement with only such presentation of detail as may be essential for explanation of views and recommendations divergent from those of the District Engineer. Where the Division Engineer concurs with the District Engineer a statement to this effect will be sufficient.

PRELIMINARY EXAMINATIONS, FLOOD CONTROL

281. Form and order of report. The report on preliminary examination will contain the following subject matter in the order stated, and in form and style to be easily readable and understandable even by those not familiar with Department procedure. Subheadings should conform in general to those given below, but headings may be omitted where there is nothing to report and additional headings used where necessary. If the matter included under any heading is