Breached 408-MW Taum Sauk to be off line through 2008
Ameren Corp. said its 408-MW Taum Sauk pumped-storage project will remain closed through 2008 while the company evaluates whether to rebuild its breached upper reservoir.
The Missouri project has not operated since the upper dam breached in December 2005, releasing 1.4 billion gallons of water, injuring nine people, and damaging property.
Ameren President Gary Rainwater told analysts that Taum Sauk would remain closed though 2008, and perhaps longer. The utility has not decided whether to rebuild the facility, spokesman Mike Cleary said.
In October 2006, Ameren subsidiary AmerenUE agreed to a settlement with the Federal Energy Regulatory Commission (FERC) that calls for the utility to pay $15 million to address the breach. That payment includes a $10 million civil penalty, the largest FERC ever imposed in a hydroelectric matter.
Costs associated with the breach, including the settlement agreement with FERC, reduced Ameren ’s third quarter 2006 net income by about $17 million, or 7 cents per share, compared to the same quarter in 2005, the utility said.
An investigation blamed the breach on overtopping of the dam due to improperly installed and maintained water level monitors and emergency backup sensors, as well as poor construction practices and inadequate attention to dam safety.
Dam organization accepts scholarship applications
The Association of State Dam Safety Officials (ASDSO) plans to award up to $10,000 in scholarships to undergraduate students in 2007.
Applications for the scholarship program can be obtained directly from ASDSO ’s Internet site, www.damsafety. org. Applications must be postmarked by March 30. Successful candidates are to be announced in June.
Applicants must be U.S. citizens enrolled at the senior level during the 2007-2008 school year in an accredited civil engineering program, or in a related field. Applicants must demonstrate an interest in a career in hydraulics, hydrology, or geotechnical disciplines, or in another discipline associated with dam design, construction, and operation. They must have a cumulative grade point average of 2.5 for the first three years of college.
Canadian Dam Association recognizes award winners
The Canadian Dam Association (CDA) presented awards in several categories to members at its annual conference, held in Qué bec City, Qué bec, in October 2006.
Award categories were: Inge Anderson Award of Merit; Published Paper Award; Student Award; and Peter Halliday Award for Service.
Gaé tan Guertin, a former hydraulic and environment manager retired from Hydro-Qué bec, was named recipient of the Inge Anderson Award of Merit. The award is offered every two years to an individual who has contributed significantly to advancement of dam knowledge and practices in Canada.
Stephen Rigbey, project manager, Hatch Energy, was named winner of the Published Paper Award for “Monitoring Upstream Sinkhole Development by Detailed Sonar Profiling. ” The paper was published in CDA ’s 2005 conference proceedings. The award is offered to authors who prepare and publish an outstanding article or technical paper on dam-related issues in Canada.
Marc Smith, who completed his doctorate at Ecole Polytechnique de Montreal, and Megan Sheffer, a PhD student at the University of British Columbia, shared the Student Award. The award was created to encourage university students to consider careers in dam-related disciplines. Each recipient receives a C$500 cash award and a CDA membership.
Mona Bechai, president of MOBEC Engineering, in Toronto, and Yousef Hammamji, chief geotechnical engineer at Hydro-Qué bec, were named recipients of the Peter Halliday Award for Service. The award, presented annually, recognizes the efforts of members who have demonstrated outstanding commitment to CDA, and who have made valued contributions to its advancement.
U.S. awards $23.9 million to strengthen Stony Gorge
The Bureau of Reclamation awarded a $23.9 million contract to Shimmick Construction Co. Inc. to modify and strengthen Stony Gorge Dam, on Stony Creek 25 miles west of Willows, Calif.
Shimmick, of Hayward, Calif., is to perform work intended to prevent the structure from failing in an earthquake. The work will involve construction of a concrete wall and additional supports between the dam ’s vertical buttresses to provide increased stability.
Reclamation said 2001 risk studies found the dam posed an unacceptable risk to downstream residents. Later studies indicated a large earthquake could cause the vertical concrete buttresses that support the dam to buckle, possibly leading to dam leakage or collapse.
Reclamation said work on the 139-foot-tall, 868-foot-long dam – scheduled to begin by the end of 2006 – could take up to three years to complete.
The reservoir behind Stony Gorge Dam has a storage capacity of about 50,000 acre-feet. The dam regulates flows along the lower reaches of Stony Creek and stores water for irrigation, hydropower, and recreation.
Part of the Orland Project, Stony Gorge Dam is owned by Reclamation and operated by the Orland Unit Water Users Association. The city of Santa Clara ’s Silicon Valley Power utility operates a 4.9-MW hydro plant at the dam, Stony Gorge.
The government said the work would affect water releases and Santa Clara ’s hydro plant minimally. Local water users will be responsible for reimbursing the U.S. government 15 percent of the cost of modifying the dam.
 Dam Incidents Reported to the National Peformance of Dams Program |
Stony Gorge Dam was completed in 1928; the hydropower plant was added in the mid-1980s. In 1986, the dam was modified to reduce danger posed by extreme flood events that could overtop the dam. It was modified to allow overtopping of one side of the structure, and a concrete slab was placed downstream to prevent foundation damage.
Safety program in progress at Canada ’s Springbank Dam
The city of London, Ontario, and the Upper Thames River Conservation Authority are rehabilitating Springbank Dam to make the 77-year-old structure conform to modern dam safety requirements.
Work began in September 2006 to repair concrete and replace stoplogs with new flap gates. To be completed in March 2007, the improvements are to enable the dam to manage debris better and to operate safely and efficiently.
Hatch Energy of Niagara Falls, Ontario, a consulting engineering firm, is overseeing the rehabilitation by MacLean Taylor Construction Ltd. of St. Marys, Ontario, which received a contract from the city in August 2006.
Springbank Dam was built in 1929 on the main branch of the Thames River in southwest London to create a local water supply reservoir and to provide recreation. Overtopping of the dam due to debris accumulation during a flood in 2000 raised concerns about the structure ’s safety. Subsequent studies recommended the dam be rehabilitated to meet Ontario safety requirements.
The city owns the 220-foot-long, 32-foot-tall dam, which the Upper Thames River Conservation Authority manages under contract for recreation, flood protection, and fisheries.
Government completes Waterbury Dam repair
A $20.5 million project to repair seepage and other problems at Waterbury Dam in Vermont is complete. The government said it will monitor performance of the 187-foot-tall dam for 18 months to ensure seepage control features operate satisfactorily.
The state of Vermont approached the U.S. Army Corps of Engineers in 1999 for help in addressing seepage problems at the dam. The state lowered the reservoir in 2000 due to dam safety concerns. It lowered the reservoir again in 2002 when the Corps began work on the structure, a rolled earthen embankment about 1,850 feet long at its crest.
Green Mountain Power Corp. owns and operates a 5.52-MW hydropower facility at the dam. The Waterbury Dam hydropower plant operated during the dam repair, but at a reduced capacity.
A 2004 federal appropriations bill directed the Corps to design and construct a repair for the dam ’s concrete spillway and abutments supporting the tainter gates. The concrete was deteriorating due to an alkali aggregate reaction.
Alltech Engineering repaired the spillway. RAITO Inc. repaired the seepage problems, while Fleet Environmental restored and stabilized portions of the reservoir banks and planted plants for erosion control.
Waterbury Dam is located on the Little River, upstream from its junction with the Winooski River. The Corps designed the dam as part of a regional flood damage reduction plan for the Winooski River Basin. Construction was initiated in 1935, and the Civilian Conservation Corps completed the dam in 1938, under the supervision of the Corps of Engineers. The dam was turned over to the state of Vermont for operation and maintenance as a flood damage reduction facility. Subsequently, power generation was added in 1953. Recreation also was added.
The state of Vermont authorized refilling of the reservoir behind the dam in September 2006.
Canadian Dam Association names officers, directors
The Canadian Dam Association (CDA) announces new officers and directors for 2007.
Tony Bennett of Ontario Power Generation is CDA ’s new president. He replaces Bob Barnes of Newfoundland & Labrador Hydro, who moved to past president.
Sayed Ismail, a hydromechanical consultant in New Brunswick, was elected vice president. Mona Bechai of Mobec Engineering, Ontario, is CDA ’s secretary and treasurer.
Seven new members of the board of directors are:
– Terry Armstrong of Manitoba Hydro;
– Gilles Bourgeois of GENIVAR;
– Bill Duncan of the Saskatchewan Watershed Authority;
– Chris Grä pel of EBA Engineering Consultants Ltd.;
– Charles Holder of BC Hydro;
– Perry Mitchelmore of Mitchelmore Engineering Co. Ltd.; and
– E. Gerard Piercy of Newfoundland & Labrador Hydro.
Other members continuing on the board are:
– Joe Farwell of Ontario ’s Grand River Conservation Authority;
– Darrell Fisher of ADI Ltd.;
– Phillip Gilks of New Brunswick Power Corp.;
– John Morrison of Alberta Environment; and
– Tony Polyck of the Yukon Department of Environment.
Directors ending their terms are: Tony Chislett of Newfoundland Power; Daniel Lavallé e of Qué bec; Clare Raska of BC Hydro; Gé rard Verzini of Hydro-Qué bec; and Barry Warner of Manitoba Hydro.
Barry Hurndall is the organization ’s executive director. He can be contacted at: P.O. Box 4490, South Edmonton Postal Station, Edmonton, Alberta T6E 4X7; (1) 780-432-7236; E-mail: bjhcda@telusplanet.net. CDA ’s Internet site address: www.cda.ca.
Document provides guidance for removal of Texas dams
A new document published by the Texas Commission on Environmental Quality (TCEQ) provides guidance to dam owners who are considering the removal of a dam. The document outlines questions to consider, and steps and procedures.
In the introduction to the six-page document, Dam Removal Guidelines, TCEQ said its Dam Safety Program is not opposed to dam removal. However,
Dam Incidents Reported to the National Performance of Dams Program
Note:
1Incidents are defined as “events of engineering interest that provide insight to the structural and operational integrity of a dam. ” This definition includes, but is not limited to, dam failure, deterioration, unsatisfactory findings during periodic inspections, and dam safety modifications.
TCEQ said the Dam Safety Program does want to ensure the process is conducted safely and in accordance with all applicable state and federal rules.
The guidelines are organized into six general categories:
– Safety issues;
– Erosion prevention and sediment control;
– Ecological issues for projects affecting wetlands or U.S. waters, and/or wildlife habitats and endangered species;
– Floodplain management;
– Stakeholder issues: historical and archeological preservation; transportation, access, and utilities; public and private interests; and Federal Energy Regulatory Commission approval; and
– Ownership issues: ownership and responsibility; water right permit; and liability.
TCEQ said each of the general categories should be considered before the dam removal process is initiated. However, it emphasizes that not all items on the list might be applicable to a particular dam. Factors such as environmental condition, size, usage, and ownership will vary on a case-by-case basis. The guidelines state it is up to the owner or the owner ’s engineer to evaluate each item, and take the necessary actions.
The document, published in September 2006, is available in PDF format on the TCEQ Internet site: www.tceq.state. tx.us. The publication number is GI-358.
TCEQ said it planned to follow up the release of the dam removal publication with a hydrologic and hydraulic guide, and guidelines for operations and maintenance of dams.
