OCR Text |
Show EMBANKMENTS ARE SATO I City Engineer of Ogden Makes Report on Sprier River lfB Projects Discovers a Serious Defect in Construction Why the Hatchtown Reservoir Gave Way. 'gap This morning Mayor A. G. Fell presented pre-sented to the city board of commissioners commis-sioners the report of City Engineer Washington Jenkins on his observations observa-tions at the Hatchtown dam on the Sevier river which washed away a short time ago and destroyed a large acreage of farm crops. Mr. Jenkins was directed by the commission to make an inspection of the dam for the purpose of gaining information regarding defects in dam construction, inasmuch as the city is engaged in reservoir building on the South Fork of Ogden rher and It is desired that advahtfejs be taken of the mistakes of othj in making more certain the stability oT the Ogden Og-den dam. While Engineer Jenkins' report Is not of great length, it is comprehensive comprehen-sive and reaches the conclusion that the Hatchtown dam was bull of earth without bedrock and that it was poorly poor-ly constructed aud poorly planned, and there is a strong hint that the Piute dam is In danger. The report follows . "Gentlemen I am herewith submitting sub-mitting a report of Investigations made by me of the Piute dam and j reservoir, in Piute county and of the Hatchtown dam and reservoir, in Garfield Gar-field county, this state, immediately after the breaking of the latter dam. which occurred on the 25th of May of the present year. "Both these dams were state projects, pro-jects, built to store water for irrigation irriga-tion purposes; the lands to be irrigated irri-gated being located at various points along the Sevier river, owned by the state, under grant from the general government. "Tbe Piute. Hatchtown and Otter Creek reservoirs, together, constitute a storage sjstem for the flood waters wa-ters of the upper Sevier river. There j are also other projects further down the river of considerable importance. "The flow In the Sevier river reaches reach-es a very low stage during the latter part of the Irrigating season, and to offset this shortage the storage in the reservoirs is commenced early In the spring time. "The Otter Creek dam and reservoir reser-voir Is located about IS miles southeasterly south-easterly I'rom the Piute dim, on a tributary of tbe Sevier river, which I did not have time to inspect, Piute Dam. "The Piute dam is located on the Sevier river, about 12 miles south of Marysvale, in a deep and narrow pass between a solid rock cliff on the west, and a shaley and earth ridge on the east. The dam is a hydraulic fill embankment, em-bankment, without corewall, 95 feet in height at highest point, and about 900 feet long on the top The top width is about 400 feet, and the slopes on both faces are 2 feet horizontal hori-zontal to 1 foot vertical, well paved with stone: the bottom width Is about 400 feet, and the slopes on both faces are 2 feet horizontal to 1 foot vertical, well paved with stone; the bottom width is about 420 feet. A concrete cut-off wall roaches from bedrock to a few feet above the river bed The outlet consists of a tunnel about 8 feet by 9 feet built through the solid rock "ledge to the west, and Is controlled by three gates built on the face of the ledge at the upper end of the tunnel. The spill-way is i built through the hill at the east end of tho dam, and is about 25 feet wide, most of which is in earth. "The water for sluicing the earth into the dam was supplied through a pipe line about 2 miles long from springs. The total head of water was about 400 feet. The work was com menced under the direction of Caleb Tanner, state engineer, Joseph Jensen, Jen-sen, assistant, having immediate charge of the work. The dam proper has cost about $250,000 and is now verv nearly completed Its storage capacity is about 50,000 acre-feet. The water in the reservoir is now about 70 feet deep at the deepest point, and backs up the river about 7 or 8 miles. The capacity of the outlet tunnel tun-nel appears to have about reached Its limit at this time, in discharging the extra flood water now pouring In from the Hatchtown reservoir. The ui stream slope of the Piute dam appears ap-pears to be built on a true slope of 2 to 1, but the downstream face of the slope has bulged, or "creeped," horizontally hori-zontally about 6 or 8 feet along the center of the dam for its entire length nearly. This may have been caused bv using an excessive amount of water wa-ter in the puddle core, but the face of the bulged line indicates an amount of saturation possibly reaching reach-ing through the dam from the water in the reservoir. There Is a small amount of seepage passing through or under the dam at the present time. Slow Construction. 'The construction of this dam is being carried on by day's work, there being now about 25 teams and a few I pxtra men employed The dirt for the dam Is being hauled about 500 to , 1000 feet by wagons and dump-boards. dump-boards. There is one very notice-able notice-able feature In connection with the work being done, namely, the v ery low rate of speed per minute attained bv the teamsters; they certainly have reduced this to its lowest terms. Krom actual observation, I found one team moving at the rate of about one foot per second, which was a fair aver age for all the others. On inquiry, 1 found that they were all bound by a mutual understanding to quit work as soon as the foreman urged them to move faster, and. as team? are scarce in the vicinity, the wo'to would have to be suspended. "At tbe time of making tho trip to this dam. June 2nd. and Sr0 the roads at a number of points c- Circle J ville canyon trtre impaiaable fer I teams, having been, .Wahedut bv finfe the floods, so the tf'tp from tfor?! M vale to Hatchtown bad to he made j mostly on horseback, a distance of I about 74 miles The district covered by the flood extended from Hatch- I town to CIrclevHie. 50 miles in lenfeth, I by about one-half mile In width along WW the Sevier river. jBfl "Wreckage of all descriptions mark- H ed the course of the flood. Houses, barns, fences, trees, implements, tele- I phone poles, logs, fn . fact anything that would float, was moved and up-rooted up-rooted and carried aloirg in the mad rush of waters. A few farms and W gardens were entirely ruinsd bv li lv. HH ing three to four feet of earth and flR boulders spread over them. The, BBS whole area had a thick coatins; of 9H clay and sand spread upon it, caused partly by the unusual amouut o this material carried in the river at this season of the year, the stream bein? M thick with sediment. The depth of thjB water ranged from about 10 tofA (eet, and traveled at the rate of jfl 6 miles per hour. No lives fFH but there were some ntrrnisJIecajH People r Surprised. t "A number of tbe leading citizens WPI , the community with whom I conveiH'py ed on the matter, said that they weijffl not surprised ery much when ther dam failed, as they did rot consider it. j very safe. The Hatchtown dam j located JH nbout 18 miles south of Panguitsh. on V the Sevier river, at a point Hifiout 10 M'V miles below where the Vnnioth fl , creek empties iuto the rivJfcthere W , boing a small town of tTf Jutme ! I ' about one mile north of tEWMjn. from ' I which it takes us name, I "The dam was an cajT; Bk- Ldfc, mem 50 feet higb. 6no jfl K about 10 or 12 feet wideH iSOH side slopes of 2 teet tiorlBM, fl one foot vertical. The dam 'iSfe4H directly across the bed of tfl without either corewall or c u of any kind, except, perhapa, )rWPKilW core. It v,us built under the dlrectJIIBte'jffl of the state engineer, Caleb Taattf,BtK Mr. Joseph Jensen, assistant, Having immediate charge of the work d con B$l!p53 atmction. Mr.-Brinton batTtV. 'cV 7 tract Tor the work. The west end j'V-'V of the dam was built against a lavs j H and earth bill, and the east eod rest- H' ed against a sand and clay hill. I "The water front of the dam was I riprapped with stone, but the down stream slope was unprotected. A con- crete culvert 4 feet by 6 feet was H built directly through the middle of the dam, and controlled by two gates. fl operated from a gate tower above, there being a bridge from tbe top of the dam to the gate house. 1 "There were a number of large J springs of water flowing from tbe hill on the west end of the dam, and the embankment was built so as to cover these over; but they had been pipf in such a way as to lead Into the cjB vert. There were springs aleodfl the east end of the dam whjfl been taken care of in the sail ner. k Where the Leak Occ "This dam cost about was completed about threiH examined the elevation oriWBBH face of the water in the darn wmark-ed wmark-ed by rubbish on the bank,aad Ifound it to be within about eight eet from the top of the dam. The wjljSr ilrst I began to leak through the da on the I I downstream face, at a point about 5 feet above the outlet cuKert. In stream frTat would fill a 4-tncb pipe, at 2 o'clock in the afternot'. and at 8 o'clock the whole bodyf water 'i I was pouring through the break. It took about one hour for 75 per cent of the water in the reservoir to flpw out "The reservoir held about 12,000 acre feet, and backed the water up J stream about two miles. Examination Examina-tion of the bottom of the reservoir after being emptied shows it to have silted up about three or four feet In as many years. k Gates Blown Out. Agfl "It was stated by reliable partB who were present that, soon after tM completion of the dam, about tirm years ago. the outlet gates becanuB r-'' stuck and refused to operate whiTl v .'t'. the reservoir was filling, and, in or-B"' der to save the entire structure. th B-'"f gates were blown out with dynamite, more than 70 sticks being used in the H operation. After the reservoir was j I I emptied, new gates of a different de- I sign were Installed, and the dame v I I caused by the explosion repaired, in apparently a satisfactory manner. The dynamiting may have caused n perma- nent injury to the. dam. which waa 1 overlooked in repairing the same. U i am of the opinion that the dam was both poorly designed and poorly I constructed, which was the main cause of its failure. I also believp ' , that the slopes for earthen dams should not be less than 2 12 feet horizontal to 1 foot vertical, or more. and that an earth dam should not h built to any considerable height without with-out a concrete corewall " |