Close 

Dam Safety & Security

Michigan announces plan to bolster state's dam safety

Michigan's Department of Natural Resources announced a Dam Management Grant Program in October to address the state's failing infrastructure.

The grant will provide US$2.35 million in the 2013 fiscal year to fund dam removal and maintenance, as per a 2011 address by Michigan Governor Rick Snyder.

"This program begins to address a growing issue for our state as more than 90% of Michigan's dams will reach or exceed their design life by 2020," says DNR Director Keith Creagh. "Many dams are abandoned, no longer serve any useful purpose, degrade our aquatic resource, and pose safety hazards to downstream residents."

The program will provide funds and technical assistance to local and state units of government, non-profit groups and individuals to manage dam removals, repairs and maintenance projects.

DNR says it will focus on projects that reduce the state's long-term infrastructure costs, while also addressing those that pose an imminent hazard to the public.

The agency says that nearly 75% of the more than 2,600 dams listed in the state's inventory are privately owned and in poor condition. A 2009 report by the American Society for Civil Engineers gave Michigan's dams a "D" grade on its Dam Infrastructure Rating report.

Corps awards multiple contracts for repair and safety work

The U.S. Army Corps of Engineers awarded several contracts for dam safety, construction and rehab work and announced projects in development.

Plunge pool repairs at 185.3-MW Fort Peck

ASI Constructors Inc. has received a contract worth US$33.9 million to repair the plunge pool at Montana's 185.3-MW Fort Peck project.

Work needed is in response to 2011 flood damage in the Missouri River Basin that includes Fort Peck and five other Corps hydro plants.

Per the contract, ASI Constructors will "improve the stability of the cutoff structure by filling a significant portion of the scour hole with roller compacted concrete (RCC) and installing tieback anchors through the existing cutoff wall."

The company will also use training walls for the placement of backfill, which will support the existing cutoff structure wing walls to help divert erosive flows.

Safety work at Bluestone Dam

The Corps has awarded a contract worth US$94.7 million to Heeter Construction Inc. for the installation of 278 high-capacity multi-strand anchors at Bluestone Dam in West Virginia.

The Corps' Huntington District says the work must be done in accordance with its Dam Safety Assurance Program. According to the program, a downstream hazard assessment indicates there is sufficient justification to modify the project to accommodate 100% of the probable maximum flood.

The dam, which began operation in 1948, contains 55 monoliths. Work on the Bluestone Dam stability project began in 1998 and is being executed in five phases. This latest project is Phase 4, which includes the installation of high-strength anchors primarily over the stilling basin.

Missouri River hydropower rehabilitation projects

The Corps awarded a pair of contracts for work at two hydroelectric projects located on the Missouri River.

The first - a US$4.1 million contract awarded to J.F. Brennan Co. - calls for the rehabilitation of spillway gates at South Dakota's 494-MW Big Bend.

The Corps' Omaha District says the work includes three-dimensional modeling and analysis; non-destructive testing; structural repair design; welding; corrosion repair; sandblasting; lead-based paint removal; wire rope replacement; concrete spall repair; gait seal replacement; and painting, design and replacement of hoist controls and switches.

Second, the Omaha District awarded a $597,800 contract to Dakota Earthmoving Inc. for bank stabilization at 786-MW Oahe Dam in South Dakota.

Both of the above projects are a response to 2011 flooding in the Missouri River Basin, which also includes work at other Omaha District hydropower facilities.

Garrison Dam flood control tunnel interior repairs planned

The Corps plans to perform flood control tunnel interior repairs at 517.8-MW Garrison Dam on the Missouri River in North Dakota.

The Corps' Omaha District recently awarded a contract worth US$3.4 million to ESCI Contracting Corp. to rehabilitate drainage systems at Garrison. The Corps has been soliciting a large volume of contracts to repair 2011 flood damage in the Missouri River Basin, including work affecting Garrison and five other major Corps hydro projects.

The work will include removal and replacement of intake structure gantry crane wire rope, the east side air seal on flood control tunnel regulating gate No. 7, and trunnion bearing oil seals on three regulating gates. In addition, the trunnion bearing oiling system is to be refilled and evaluated for defects.

Rehab work at Ohio's Bolivar Dam

The Corps awarded a contract worth US$4.7 million to TAB Construction Co. Inc. for work at the Bolivar Dam in northeastern Ohio, including the installation of six service gates and the rehabilitation of gate works at the flood control structure.

TAB will install the six service gates in the dam's intake structure - including five to be fabricated and a sixth to be supplied by the government. Other work includes rehabilitation of gate recesses, such as repair, cleaning, and painting of the liner and repair of damaged concrete. In addition, service gate machinery and electrical components will be upgraded.

Bolivar Dam is an 87-foot-tall, 6,300-foot-long embankment structure on Sandy Creek, a tributary of the Tuscarawas River.

RCC berm at Center Hill planned

The Corps plans to construct a roller-compacted-concrete berm to reinforce an earthen saddle dam at 135-MW Center Hill Dam in DeKaib County, Tenn.

The Corps' Nashville District is in the process of choosing a firm to perform blasting and excavation of foundation rock, grouting, and construction of the RCC berm immediately downstream of the water-retaining saddle dam.

Work includes excavation of 5,000 cubic yards of rock up to 20 feet deep, a dual line grout curtain, and blanket grounding with estimated total grout of 100,000 cubic yards. The RCC berm would be 100 feet high and 900 feet long with up to 200,000 cubic yards of concrete.

Reclamation awards contract for work at Guernsey

Moltz Constructors Inc. has been awarded a contract worth US.8 million for structural modifications at Wyoming's 6.4-MW Guernsey Dam.

The U.S. Bureau of Reclamation said the work includes the removal of a concrete parapet wall and concrete in the back wall, shaft lining, and tunnel lining; placing cast-in-place concrete for new south spillway overlay walls and weir wall, and parapet wall; concrete repairs to back wall, shaft lining, and tunnel lining; excavation of existing dam embankment; construction of two-stage filter of sand filter and gravel drain materials at dam embankment and north spillway wall; installing collector drains; removing left drum gate and abandoned drum gate control piping and control valves; and rehabilitation of the right drum gate.

The modifications will secure and update the infrastructure and provide an increased level of safety to those downstream of the dam.

Guernsey Dam is part of Reclamation's North Platte project, which extends 111 miles along the North Platte River Valley from Guernsey to Brideport, Neb.

USSD 2013 Annual Meeting and Conference to be held in Phoenix

The U.S. Society on Dams' Annual Meeting and Conference will be Feb. 11-15, 2013 in Phoenix.

The program includes several workshops, more than 100 technical presentations, and field tours to the Salt River Project's Roosevelt Dam and Central Arizona Project Headquarters and New Waddle Dam. The program includes a wide variety of presentation topics and tracks, covering all facets of the dam industry, including safety and security, design and construction, operations, and environmental matters. The workshops will cover risk assessment, responsible cost estimating, and instrumentation.

Nominations are due by Dec. 15 for the Lifetime Achievement Award and the Excellence in Constructed Projects Award. Honors for Outstanding Papers will also be presented.

USSD will also present three scholarships to graduate students, one for US$10,000 and two for US$1,000. Student members should apply by December 14. Scholarship winners will also receive complimentary Phoenix conference registration, lodging, and travel expenses. Additional details are available at www.ussdams.com/2013conf.

CDA seeks to update and improve dam safety guidelines

The Canadian Dam Association's Dam Safety Review Working Group conducted a survey of the association's membership that will be used to improve its dam safety review guidelines.

The feedback, which includes information on its information will be analyzed and used to improve the dam safety review process diagram, which serves as a starting point for the organization's dam safety reviews technical bulletin.


To access this Article, go to:
http://www.hydroworld.com/content/hydro/en/articles/hr/print/volume-31/issue-08/departments/dam-safety-security.html