Hydropower, Storage

Dam Safety & Security

Issue 2 and Volume 26.

Congress allots $59 million to extend dam safety program

A spending authorization totaling $59.2 million over five years is included in legislation that reauthorizes the National Dam Safety Program for another five years.

Congress passed S.2735 on Dec. 9, 2006, extending the dam safety program through Sept. 30, 2012, the end of fiscal year 2011. President Bush signed the measure Dec. 22.

The National Dam Safety Program provides incentive grants to encourage states to improve dam safety programs through training, technical assistance, research, and support.

The act authorized appropriations totaling $59.2 million for the five years, including amounts to be shared by states and allocated based on the number of dams in each state. Congress must make actual appropriations each year to implement the spending authorization.

Legislation that would have created a $350 million National Dam Rehabilitation and Repair Program for non-federal, publicly owned dams was not considered by the last Congress before the session ended.

DHS offers training for protecting infrastructure

The U.S. Department of Homeland Security’s Office of Infrastructure Protection now offers Internet-based training to introduce the key concepts of the National Infrastructure Protection Plan (NIPP).

Work began on the NIPP following terrorist attacks of Sept. 11, 2001, which raised awareness of the potential vulnerabilities of critical infrastructure and key resources. The NIPP, released by the Department of Homeland Security (DHS) in June 2006, defines critical infrastructure protection roles for government, industry, and non-governmental organizations.

The training is intended for government and private sectors involved in implementing programs to protect infrastructure.

DHS and the Federal Emergency Management Agency’s Emergency Management Institute (EMI) collaborated on development of the course, “Introduction to the National Infrastructure Protection Plan.”

The course (IS-860) is free and can be taken for credit or for informational purposes. It is offered through EMI’s on-line learning center and can be accessed through the EMI Independent Study website: //training.fema.gov/ EMIWeb/IS/crslist.asp.

In addition to the training program, the government maintains an Internet site, dhs.gov/nipp, that provides public access to NIPP documents and related links and information.

Corps lowers Kentucky lake to reduce dam failure risk

The U.S. Army Corps of Engineers said it expects lowering the level of Kentucky’s Lake Cumberland will reduce the risk of Wolf Creek Dam failing.

The Corps said it would spill water and release water through the project’s 270-MW powerhouse over about two weeks to reach a target level of 680 feet. By reducing water pressure on the dam, the Corps said it could lessen the risk of dam failure and limit seepage through the dam foundation.

The Corps already was carrying out rehabilitation work to address the seepage problem. However, it decided to reduce the water level further based on its own recent studies and independent studies following Hurricane Katrina.

Those studies classified Wolf Creek Dam as being at “high risk” for structural failure. However, the Corps said the dam is not in imminent danger of failing.

“A high level of risk does exist,” District Commander Lt. Col. Steven Roemhildt said. “Reducing the lake level lowers pressure on the dam and the pumping of grout into the ground lessens erosion, both of which immediately reduce risk.”

The half-century-old dam has experienced foundation seepage for years. However, the Corps said pressure from water in the reservoir eventually eroded soil-filled spaces in the rock beneath the dam. Citing the seriousness of the foundation seepage, the Corps said it is accelerating the grouting program. It said lowering the lake level would simplify grouting work.

Funding sought to accelerate construction

The Corps said it would request full funding to $309 million from Congress to accelerate construction of the remedial project, which includes not only grouting but construction of a concrete diaphragm wall to reinforce the original wall. The work could take ten to 12 years, a Corps spokesman said.

The Nashville District awarded a construction contract in December 2006 for grouting work. Advanced Construction Techniques Ltd. of Kettleby, Ontario, is carrying out the $14 million contract, pumping grout into areas to control seepage.

The Corps has operated the reservoir since March 2005 to maintain lake levels within a lower range. It will maintain the 680-foot elevation for the remainder of 2007. It plans to re-evaluate lake levels in September or October for 2008 operation. Dam safety experts will monitor conditions and more reductions might be necessary, depending on how lake levels affect the dam.

The 5,736-foot-long, 258-foot-tall rolled earthfill and concrete gravity dam is located in Kentucky and impounds the largest reservoir east of the Mississippi River. Normal pool levels are 723 feet in summer and 690 feet in winter.

While the lower lake level is expected to reduce generation at Wolf Creek, the Corps said it could make up for losses by increasing generation at other hydro projects in its system. Additionally, fossil generation could make up some losses.

Reclamation awards contract for Deer Creek spillway work

The Bureau of Reclamation awarded a $1.2 million contract in January to Moltz Constructors Inc. to make improvements to the spillway of 4.95-MW Deer Creek Dam, part of the Provo River project in Utah.

Moltz Constructors, of Cody, Wyo., will perform tasks during Phase II of the federal government’s multi-phase Safety of Dams Modification project at Deer Creek Dam. In that phase, the contractor will remove deteriorating concrete sections and install reinforced concrete, grouted anchors, and dowels in spillway chute floor slabs and walls. It also will install PVC plastic water stops at concrete joints.

Reclamation began the first phase of work in 2003 in a program to modify the 235-foot-tall, 1,300-foot-long zoned earthfill dam and spillway structure to enable it to withstand a large seismic event. Reclamation and Utah’s Department of Transportation are working on that initial phase, a highway improvement project in Provo Canyon around the dam. That part of the project includes construction of a bridge spanning the spillway and realignment of the highway that previously crossed the top of the dam.

Brookfield Power completed a $3 million surge tank and penstock replacement program at its 4-MW Allens Falls plant on New York’s St. Regis River in response to federal safety requirements.
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Phase III work will involve the upper portion of the spillway control structure, and raising the crest of the dam.

Reclamation anticipates finishing highway improvement work in early 2008, and all dam safety work by 2010.

Deer Creek Dam is the main feature of Provo River project, which Reclamation built for the Provo River Water Users Association to provide agricultural, municipal, and industrial water. Its reservoir impounds 153,000 acre-feet.

The Deer Creek hydro plant was commissioned in 1958. It houses two turbine-generators that generate electricity to replace energy lost at other power plants through storage and diversion of water for irrigation during the winter season.

New surge tank meets seismic concerns in New York

In response to federal safety requirements, Brookfield Power reported it completed a $3 million surge tank and penstock replacement program at the 4-MW Allens Falls hydroelectric plant on New York’s St. Regis River.

Brookfield said the six-month-long upgrade, completed in November 2006, meets Federal Energy Regulatory Commission requirements to withstand a seismic event, as specified by its license to operate the plant, part of the 6.8-MW West Branch St. Regis River project. The work was among a series of multi-million-dollar project upgrades in New York.

B-S Industrial of Gouverneur, N.Y., carried out the upgrade, which included installation of a surge tank to replace a tank that had been in service since the 1920s. Work also involved removal of 1,500 feet of penstock that carried water from the St. Regis River to the hydropower plant. Additionally, new foundations, ring girders, and 1,500 feet of new, 7-foot-diameter steel pipe were installed.

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