Item (1) Dams and appurtenances, including gages... (3) Interest during construction 1. Bear Creek $441, 600 None 505, 460 96051-44- -3 15, 160 6,700 500 22, 360 24, 540 2,600 None 27, 140 1,090 290 1,850 10,000 13, 230 10,000 3, 230 25, 590 Mariposa $561, 600 None 573, 940 17, 220 7,610 500 25, 330 19,860 6, 500 7,800 None 34, 160 1,370 360 2,100 6, 600 10,430 6,600 3,830 29, 160 Total $1,003, 200 76, 200 None 1,079, 400 32,380 14, 310 1,000 47, 690 XIV. BENEFITS FROM IMPROVEMENTS harr 64. Tangible benefits.-Benefits which would result from the proposed project have been based on normal economic conditions. Tangible benefits would be limited to flood-control benefits since no appreciable collateral benefits would result. 44, 400 6, 500 10, 400 None 61, 300 2, 460 650 3,950 16, 600 23, 660 16,600 7,060 54, 750 65. Flood-control benefits.-Tangible flood-control benefits would consist of (a) the elimination of practically all future damage which Would otherwise occur, in the developed portion of the area under consideration, as the result of floods on the streams of the Bear Creek and Mariposa Creek groups, (b) land appreciation in certain rural and suburban areas through better land use, and (c) reduction in maintenance of certain existing channels. No benefits would result the areas along Canal and Fahrens Creeks, and benefits in the relatively undeveloped area along the lower reaches of Bear, Miles, Owens, and Mariposa Creeks would be inappreciable. 66. Benefits from elimination of flood damages.-Tangible benefits from the elimination of flood damages would be due entirely to the reduction of direct damages in the developed area of Bear and Mariposa Creek groups, and on the basis of future development in the rea, would have an estimated annual value of $85,100 as determined from increasing the $74,000 damage which would occur under the present state of development (see table 16) by the 15-percent increase ntrol bene a benefits. 67. Benefits from appreciation in land values.-Benefits from appre ciation in land values would result from inprovements proposed for precis the Bear Creek group. These benefits would be due to better land use and would accrue to about 1,450 acres of rural land along Blacktion in Rascal Creek, and to about 300 acres of suburban land immediately food east of the city of Merced. The increase in value of rural lands, including that due to increased production because of the reduction ins flood damage, would average about $50 per acre which on the basis of an annual return of 4 percent would amount to $2 per acre annually. The total benefit to the 1,450 acres from this appreciation would be $2,900 less the $700 annual damage considered under direct benefits Genera a net benefit of $2,200 annually. of the ms, Be ement 68. With the proposed project in effect, the 300 acres of surburbans Cre land would probably be taken into the city of Merced. The resulting me. O increase in value, including that due to the removal of the flood threats be eff would amount to about $200 per acre, which on the basis of a 4 percent return, would amount to $8 per acre annually. The benefit to the 300 acres from this appreciation would be $2,400 less the $400 annual constr damage included in direct benefits, a net benefit of $2,000 annually and from The total annual benefit from appreciation of land values would, therefore, be $4,200. Bear, M conditio Ted beca 69. Benefit from reduction in channel maintenance.-A substantial amount of channel maintenance would be eliminated on Black Rascal is to an canals. This reduction would be partially offset by a small amounted impr and Owens Creeks by the construction of the proposed divertingood-wate ic cond of maintenance on the diverting canals. The net reduction in the cost of maintenance would represent a benefit to the project and would amount to $5,900 annually. This benefit would be almost end of hig tirely a flood-control benefit since past maintenance has been largely Local pa enance to t irrigat ed flood to relieve flood conditions. enance. 70. Collateral benefit.-No appreciable irrigation or other collateral benefit would result from the proposed project. in from the proposed project would include those which would be on purp 71. Intangible benefits.-Intangible benefits which would result e appreciable as well as those which cannot be evaluated. Such benefita would include a small benefit to irrigation interests because of the reduction in channel maintenance that would be effected by the pro channe ate prac equate c in a c posed diverting channels, and would also include a reduction in the intangible flood damages listed in paragraph 33. Some benefits migh also accrue to lands along Owens Creek below the proposed divers, to the canal because of the reclamation that would be made possible. Any benefits thus obtained, however, would be largely offset by the co of such reclamation. 72. Summary of benefits. The average annual tangible benefit which it is estimated would result from the proposed improvements are summarized in table 21. tion anc sual maint interests $600. In view of interests s ng items: lands an Relocation improveme largement nich T Food-control benefits: Elimination of direct flood damages.. XV. DISCUSSION de C acres of the 73. General.-There is urgent need for the control of floods on ost of the creeks in Merced County. The control of Canal and ahrons Creeks, where flood damages are minor, is not justified at his time. On the other creeks, however, control is feasible and ould be effectively provided by the proposed detention reservoirs Burns, Bear, Owens, and Mariposa Creeks, supplemented by the largement of a 2-mile constricted portion in Miles Creek, and the construction of diverting canals from Black Rascal to Bear reek and from Owens to Mariposa Creek. The improvement would iminate practically all damage resulting from floods on Black Rascal, urns, Bear, Miles, Owens, and Mariposa Creeks. Also high groundater conditions, which are serious in the area, would be greatly proved because of the better drainage permitted by channel clearing ad flood-water detention. Benefits, anticipated to result from the roposed improvement, would exceed the cost, the ratio of annual enefits to annual cost being 1.7:1. This ratio is based on normal onomic conditions, and even though the project were built during period of high prices, justification would be ample. TOPN TAL 74. Local participation.-The clearing of existing channels and their aintenance to preserve them in a clean condition is necessary for rocient irrigation, use and drainage. Successful operation of the oposed flood control is likewise dependent upon such clearing and aintenance. During the past, such clearing and maintenance for igation purposes has been spasmodic and only partially satisfactory. or adequate channels, it is necessary that clearing and maintenance done in a continuous and systematic manner. Inasmuch as the gged channels result from irrigation and drainage practices, the storation and perpetual maintenance of channels, including the rpetual maintenance of the diverting canals which replace existing annels, to the capacities shown on enclosure 3, should be done by cal interests and would require an estimated annual expenditure $16,600. ropos 75. In view of the local nature of the proposed flood-control project, al interests should participate in the first cost by paying for the lowing items: Urban... Rural...... Reduction in channel maintenance. Total flood control benefits.. lateral benefits.. Total benefits.. Total $85, 100 2,000 2, 200 5,900 95, 200 None 95, 200 All lands and rights-of-way required for the proposed plan of improvement. (b) Relocation of roads and other utilities made necessary by the proposed in of improvement. (c) Enlargement of Miles Creek to 1,000 cubic feet per second capacity. and This participation in first cost would amount to $61,300. Local inter the re 3) Or 4) Or 76. The proposed plan of improvement would adequately meet that with hic fee with 170 On 77. Central Valley project.-The Central Valley project for developervoir the res That th 79.400 That th ted po Rascal, 78. The district engineer concludes: (a) That, under the conditions of development which will probably obtain du 3; f ing the next 40 to 50 years, future floods on creeks in Merced County will result in locati an average annual damage of about $92,700 of which $85,100 would be econom That, in cally preventable by control of the streams of the Bear Creek and Mariposa Creemance groups. on be (b) That the minor damage resulting from floods on Canal and Fahrens Creek That the would not justify protection therefrom at this time, but that adequate control and dive the other creeks of the area can be provided by the construction of the improvestims ments proposed herein. Sand (c) That the cost of the improvements would be $1,140,700 of which $532,6d annu would be for the Bear Creek group and $608,100 for the Mariposa Creek group; an aims for that the annual charges, including the local interests' share of $7,060, would bent ope $54,750 of which $25,590 would be for the Bear Creek group and $29,160 for thegulatio Mariposa Creek group. ed furn 100 to c (d) That local interests should pay the cost of all land and rights-of-way, retion w and utility relocations, and should enlarge Miles Creek to provide a capacity That, if 1,000 cubic feet per second. (e) That local interests should maintain the reservoirs, including dams and the effic appurtenances, and maintain and operate the gages. (f) That the high ground-water condition created by irrigation and the use the creek channels as irrigation and drainage canals has caused the channels become overgrown with reeds, tules, and brush, and has impaired natural flow and that control of floods on these creeks is dependent upon the restoration these impaired channels. XVI. CONCLUSIONS on enclosure 3. (h) That total annual benefits would be $95,200, and the ratio of benefits cost would be 1.7:1. (i) That there is no immediate demand for additional irrigation water in th area. OFFIC (g) That local interests should restore the impaired creek channels and shou maintain these channels and the diverting canals to the capacities prescribed 61 Be XVII. RECOMMENDATIONS 250 cu CHIEI (j) That development of hydroelectric power at the proposed reservoir sites on c is not feasible. (k) That the cooperation to be required of local interests will be forthcoming distric result 50. Ap is the e agricult and w Grand enefits r aintena result (1) Between Black Rascal and Bear Creeks, a diverting canal with. The capacity of 3,000 cubic feet per second. 79. The district engineer recommends: (a) That no flood-control project be adopted for Canal and Fahrens Creek (b) That a flood-control project be adopted for Black Rascal, Burns, Miles, Owens, and Mariposa Creeks at an estimated first cost of $1,140,70rainage (c) That the project consist of the following features: (2) On Burns Creek, a detention reservoir with a capacity of 6,000 acrefeet and with an outflow of 2,000 cubic feet per second when the water surface in the reservoir is at spillway crest. (3) On Bear Creek, a detention reservoir with a capacity of 6,000 acre-feet and with an outflow of 2,000 cubic feet per second when the water surface in the reservoir is at spillway crest. (4) On Miles Creek, enlargement of channel to provide a capacity of 1,000 cubic feet per second. (5) On Owens Creek, a detention reservoir with a capacity of 5,000 acre-feet and with an outflow of 250 cubic feet per second when the water surface in the reservoir is at spillway crest. (6) Between Owens and Mariposa Creeks, a diverting canal with a capacity of 250 cubic feet per second. (7) On Mariposa Creek, a detention reservoir with a capacity of 15,000 acrefeet and with an outflow of 1,000 cubic feet per second when the water surface in the reservoir is at spillway crest. (d) That the participation of the United States in the first cost of the project e $1,079,400. (e) That the State of California or other responsible local interests enlarge the nstricted portion of Miles Creek, and restore the impaired channel capacities of Jack Rascal, Burns, Bear, Owens, and Mariposa Creeks to those prescribed in closure 3; furnish all land and rights-of-way; and construct necessary road and tility relocations; all at an estimated cost of $61,300. That, in order to protect the Federal investment and to insure adequate aintenance and operation of the proposed project, Federal supervision and spection be provided at an estimated annual cost of $1,000. A. That the State of California or other responsible local interests maintain the eeks and diverting canals shown on enclosure 3 to the capacities prescribed thereat an estimated annual cost of $16,600; that they maintain the reservoirs, includdams and appurtenances, and maintain and operate the reservoir gages, at an timated annual cost of $3,950; that they hold and save the United States free om claims for damages due to the construction of the proposed works and their bsequent operation and maintenance; that the above participation be performed ader regulations prescribed by the Secretary of War; and that the local interests ncerned furnish assurance satisfactory to the Secretary of War that aforesaid rticipation will be forthcoming. (h) That, if the proposed work is authorized, one allotment in the amount of 079,400 to cover the total estimated first cost to the United States, be made to rmit the efficient and timely prosecution of the work. R. C. HUNTER, Lieutenant Colonel, Corps of Engineers, District Engineer. [First endorsement] OFFICE, DIVISION ENGINEER, SOUTH PACIFIC DIVISION, 0 the CHIEF OF ENGINEERS, UNITED STATES ARMY. |