12-MGD LEAK ERODES EARTHFILL DAM

Bureau of Reclamation engineers are draining a 357,000-acre-ft reservoir behind Fontenelle Dam, on Woming's Green River to expose a leak that has gouged a hole the size of an office building in the earthfill dam's right bank. Water surging through a leak near the right abutment washed out a hole in the downstream face of the dam that is 80 ft across, 150 ft high and 60 ft deep. The dam is a 157-ft-high irrigation and water supply structure. BuRec designed it and supervised its construction. It was completed last year. Seepage occurred at the right abutment as the reservoir reached capacity. BuRec grouted the area and kept it under observation. Early this month members of the contractor's crew discovered the seepage had developed into a leak of 10 million to 12 million gallons per day. BuRec engineers immediately ordered release of water in the reservoir to reduce pressure on the dam and to expose the leak at the upstream face. Until they can study the leak, engineers decline to comment on its exact location or cause or the cost of the damage. Unofficially, the location of the leak is said to be in the rock in the right abutment. Because water could be released both through the spillway and irrigation canals, BuRec is able to lower the reservoir level about 4 ft per day. When the leak is exposed, BuRec will use all machinery and equipment available to fill the eroded area with heavy rock, says Chief Engineer B. P. Bellport. The drawdown has so far reduced the leakage by 50%. Fontenelle is a zoned earthfill dam, with a length of 5,000 ft and a volume of 5.3 million cu yd. Completed in August, 1964, it retained almost its total storage capacity in its first year of operation, because of high runoff in the Green River. The bureau originally estimated it would take two or three years to fill. A joint venture of Foley Bros. Inc., of St. Paul, Minn., and Holland Construction Co., of Billings, Mont., won the prime contract for construction of Fontenelle with a bid of $7.9 million in June 1961. A 10,000-kw hydro plant that is located downstream from Fontenelle Dam Was scheduled to go into operation in October. The starting date for this power plant will now depend on the amount of water that must be released from Fontenelle Reservoir. /ART/

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  • Corporate Authors:

    McGraw-Hill, Incorporated

    330 West 42nd Street
    New York, NY  United States  10036
  • Publication Date: 1965-9-16

Media Info

  • Features: Photos;
  • Pagination: p. 57
  • Serial:

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Filing Info

  • Accession Number: 00263853
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 31 1974 12:00AM