98. The estimated cost of the projects for areas A, B, and C is as hest follows: Cust. B sidered Definite project report. Specifications and drawings. Concrete flood wall. Sheet piling flood wall. Pumping plants. Subtotal. Reconstruction of streets and bridges. Miscellaneous track changes.. Rights-of-way Relaying of water mains and tide-gating of sewer outfalls. Subtotal. Total Grand total. (a) Federal investment: Estimated expenditure for new work of construction.... (c) Non-Federal investment: (1) Reconstruction of streets and bridges (2) Miscellaneous track changes. (3) Value of lands and rights-of-way to be furnished (4) Water-main changes and tide gates at sewer outlets. (5) Total non-Federal investment. (d) Non-Federal annual carrying charges: (1) Interest at 4 percent on (c) (5) (2) Amortization of obsolescence and depreciation: 50-year life at 4 percent on (c) (5) at 0.66 percent (3) Cost of operation and maintenance of structures. (4) Total non-Federal carrying charges............. (e) Total carrying charges, items (b) and (d) 165,000 28.500 B. Just 99. The annual charges of the proposed project for areas A, B, and only re C are derived as follows: Fuld be the 4. the rat 1:1.60,11 nomic fe Ced, and of area Ci 12,000 35,000 15,000 4,000 73,000 16,000 322, 200 274,500 18.000 22,000 6, 200 27.800 65,500 350,000 340,000 A 9.670 2,870 12,540 77,000 38.500 100,000 61,000 rovemer stributed $322,200 $274,500 1, 110 Area 180 2,300 3,590 16, 130 B 22,000 18.000 27,800 65.500 8.230 2,440 10.670 2,620 2,300 5,350 16,020 ges from r 100. The total annual charges for areas A, B, and C are therefore $35,490, including non-Federal charges of $9,470. estimated & 101. Average annual benefits.—It has been shown in table S, thigh tidal s with the state of development of the Grays Harbor cities at the time and large of the damage appraisal, and with flood frequencies as recorded durercial dist the last 31 years, potential direct flood damages are $72,000 annually distributed among areas A, B, C, and D in the amounts of $21,400. consisting Sewer outfa 105. Dis foods of th Bucoda Factory agr of the inun as the rive $47,200, $2,700, and $700, respectively. The damages so indicateuring fl do not include intangible damages or damages that would result from 106. Cor he highest tide (17 feet) that the levees have been designed to protect. gainst. But, as protection is to be provided from such a tide, it is onsidered proper to include under preventable damages the annual amage caused by such a stage occurring once within the 50-year ife of the project. Such an annual damage would amount to $16,720 or areas A, B, C, and D, distributed in the amounts of $4,400, $11,600, 650, and $70, respectively. Total preventable damages are, thereore, $88,720, but, as area D is not included in the proposed plan of mprovement, the total benefits for the proposed plan are $87,950, listributed among areas A, B, and C in the amounts of $25,800, 158,800, and $3,350, respectively. 102. As pointed out in paragraph 50, there would result an increase In land value of the harbor cities, if flood control were provided, of 800,000. That figure is based on information furnished by informed ocal interests and does not include any increment in value of buildings or improvements. Accepting the figure of $800,000, and assuming in annual ground rental of 7 percent, there would be a yearly increase n rental value, by virtue of flood control, of $56,000. The realization of that benefit would, however, be contingent upon the future demand or land in the present flood plain and might not come for many years. 103. Justification of project and allocation of costs.-Assuming that he only realizable benefits from construction of the proposed levees would be the prevention of future flood damages as given in paragraph 101, the ratio of the cost of each project to resulting benefits would be is 1:1.60, 1:3.67, and 1:1.00, respectively, for areas A, B, and C. The economic feasibility of the projects for arcas A and B is firmly estabished, and, as stated in paragraph 97, it is believed that the project for area C is justified because of the importance of maintaining access to Aberdeen from the south and east during flood periods. 104. In deriving the annual costs, as given in paragraphs 99 and 100, the allocation of costs has been made, using the policy established by the Flood Control Act of 1936 as a guide. That act provides for construction, at Federal expense, of those flood-control works for which annual benefits, to whomsoever they may accrue, are in excess of the annual costs; providing local interests furnish, without cost to the United States, all necessary lands, easements, and rights-of-way, agree to hold the United States free from all claims for damages arising out of the construction, and maintain and operate the works after completion. In view of the local nature of the benefits, however, it is believed that local interests should furnish additional cooperation, consisting of the reconstruction of streets, bridges, water mains, and sewer outfalls, and the making of miscellaneous track changes. 105. Discussion. The data presented in this report indicate that floods of the Chehalis River are a source of damage to urban property in Bucoda and Centralia, and a contributing cause to the unsatisfactory agricultural economy of the basin; but that, despite the extent of the inundated area and the frequency of flooding, the annual damages from river floods are only $75,000. It has also been shown that high tidal stages in Grays Harbor inundate a portion of East Hoquiam and large sections of Aberdeen and Cosmopolis, including the commercial districts in the two latter cities, and result in potential damages estimated at $88,720 a year. (See par. 101.) 106. Consideration has been given herein to all possible methods of reducing flood damages, but none of the proposed methods, so far as the river flood plain is concerned, is economically feasible under of War present conditions. The most nearly feasible method for providing estima the desired control is by storage in two reservoirs, one on the upper Chehalis River near Meskill, and one on the upper Skookumchuck sims for River, but the annual costs of such a project are 153 percent of the maintai estimated annual benefits, including liberal allowances for the value of mated an such storage for irrigation development and the abatement of pollution. Complete 107. Protection of the Grays Harbor cities can be provided only by in one levees or sea walls. Plans for such a project are presented herein. The proposed project would provide complete protection to the vicinity, except for certain water-front industries whose operations prevent the placing of a levee on the seaward side of their plants, and for a little-developed portion (area D) of Aberdeen in which the cost of providing protection is in excess of the anticipated benefits. Table 9 presents a summary of the economic justification for the various areas. TABLE 9.-Justification summary 108. It is believed that, should the project be adopted, local beneficiaries should cooperate to the extent of supplying all rights-of-way, reconstructing streets, bridges, water mains, and sewer outfalls. making miscellaneous track changes, assuming responsibility for all claims for damages arising out of construction of the project, and maintaining and operating the project works after completion. Reasonable assurance has been obtained that local interests can meet the required annual charges of $9,470 (see table 9) and that they will meet the suggested terms of cooperation if the project is adopted. 109. Conclusions. In view of the foregoing, it is concluded that the construction of levees and sea walls to protect East Hoquiam, Aberdeen, and Cosmopolis from inundation during periods of high tides in Grays Harbor is justified by the resulting benefits, and that no other work for flood control in the Chehalis Basin, either alone or in conjunction with the needs of irrigation, the abatement of pollu tion, or the development of power can be justified at this time. 110. Recommendation.-I therefore recommend the adoption br the Federal Government of a project for levees and sea walls for the protection of East Hoquiam, Aberdeen, and Cosmopolis, at estimated first costs of $669,000 for construction from Federal funds, and of $96,000 from local funds for rights-of-way, raising of streets and railroads, and miscellaneous track, water, and sewer line changes; subject to the provision that local interests also furnish, in addition to the the CHIE rk estimated to cost $96,000, assurances satisfactory to the SecreCay of War that they will hold and save the United States free from claims for damages arising out of construction of the project, and I maintain and operate the project works after completion at an snimated annual cost of $5,000. The project, if authorized, could completed in 1 year, and funds for its construction should be de in one allotment. R. PARK, [First endorsement] OFFICE, DIVISION ENGINEER, San Francisco Branch, August 25, 1943. the CHIEF OF ENGINEERS, UNITED STATES ARMY, Washington, D. C.: The division engineer concurs in the conclusions and recommendaons of the district engineer. WARREN T. HANNUM, о |