Safety Evaluation and Visual Inspection of Existing Dams

Introduction/Seminar Objectives In most countries throughout the world, interest in the safety of dams has risen significantly in recent years. Aging dams, new hydrologic information, and population growth in floodplain areas downstream from dams has resulted in an increased emphasis on dam safety evaluation, as well as operation and maintenance related to the safety of dams.

Those responsible for the safety of existing dams must implement policies and procedures that warrant public confidence. This demands professional practices that incorporate the lessons of the past and conform to the most advanced technical state-of-the-art. The need for trained personnel is essential. This seminar will provide professional personnel with a comprehensive guide to establishing or enhancing a visual inspection/evaluation program and increase the technical capabilities of those responsible for safety evaluations.

Bureau of Reclamation officials will provide the training for the seminar. Reclamation is responsible for the proper operation, maintenance, and structural safety of more than 400 dams and distribution systems. Reclamation has conducted similar seminars for its own staff, as well as for more than 4,000 technical and administrative officials from other domestic and international agencies.

Seminar Topics The first portion of the seminar will take place in Denver , Colorado , and will consist primarily of classroom presentations and discussions. A tour of the Bureau of Reclamation Research Laboratories will also be featured. Lectures, case histories, and structured discussions covering all aspects of a safety evaluation program are led by Reclamation engineers or geologists with extensive experience and knowledge in the areas of design, construction, operation, maintenance, and dam safety evaluation. The course outlines the hydrologic, seismic, geotechnical, electrical, mechanical, and structural considerations of dam safety, as well as operation, maintenance, surveillance, and emergency preparedness. Presentations, case histories, and walk-through abbreviated inspections are used to present the multi-discipline approach to an effective safety evaluation program.

Site Visits On Wednesday August 17, 2011, participants will travel to the state of Wyoming for site visits to Guernsey and Glendo Dams. The post session site visits from August 21-24, will take participants to the states of Nevada and Washington where they will visit Hoover Dam and Grand Coulee Dam.

Guernsey Dam is an earthfill dam on the North Platte River in the state of Wyoming completed in 1927. The embankment has a structural height of 41 meters (135 feet) and a crest length of 171 meters (560 feet). There are two spillways at Guersney Dam, the left (north) spillway controlled by a large Stoney gate, and the right (south) spillway controlled by two drum gates. The dam, constructed as part of the North Platte Project to provide irrigation to eastern Wyoming and western Nebraska, contains a hydroelectric plant capable of 6.4 Megawatts of electricity and a reservoir with total capacity of 87.5 million cubic meters (71,040 acre feet). Guernsey helps control the river flow and stores water released from the projects primary storage upstream at Pathfinder Reservoir. Guernsey Reservoir is severely drawn down twice a year, which affects fish population densities.
Glendo Dam is a zoned earthfill structure on the North Platte River about 6.4 kilometers (4 miles) southeast of Glendo, Wyoming completed in 1958. The embankment has a structural height of 58 meters (190 feet) and a crest length of 639 meters (2,096 feet). About 853 meters (2,800 feet) of dikes are required across a low area on the south side of the reservoir west of the dam. The dam forms a reservoir 22.5 kilometers in length (14 miles); having a total capacity of 981 million cubic meters (795,196 acre-feet). A 13-meter-wide (45 feet) uncontrolled concrete spillway is located about 137 meters (450 feet) north of the right abutment of the dam. The power plant is joined to the reservoir by a diversion tunnel 6.5 meters in diameter (21 feet) and 640 meters long (2,100 feet). The plant contains two units having a maximum rated head of 39.6 meters (130 feet) and each unit has an installed capacity of 19,000 kilowatts. To reduce the risk of dam failure due to overtopping during large hydrologic events, a new, uncontrolled ogee crest spillway will be constructed. A dam raise and modifications of the existing spillway will also be undertaken as part of a Corrective Action.

Hoover Dam and Lake Mead, spanning the Arizona-Nevada state line, are located in the Black Canyon of the Colorado River about 56 kilometers (35 miles) southeast of Las Vegas, Nevada. It is a concrete thick-arch structure, 221 meters high (726.4 feet) and 379 meters long (1,244 feet). The dam contains 2.48 million cubic meters (3.25 million cubic yards) of concrete; total concrete in the dam and appurtenant works is 3.36 million cubic meters (4.4 million cubic yards). Built during the Depression; thousands of men and their families came to Black Canyon to tame the Colorado River. It took less than five years, in a harsh and barren land, to build the largest dam of its time. Now, years later, Hoover Dam still stands as a world-renowned structure. The Dam is a National Historic Landmark and has been rated by the American Society of Civil Engineers as one of America's Seven Modern Civil Engineering Wonders.

Grand Coulee Dam is one of the largest concrete structures in the world. This barricade, which raises the water surface 116 meters (380 feet) above the old riverbed, 168 meters high (550 feet), and contains about 9 million cubic meters (12 million cubic yards) of concrete. The original dam was modified for the Third Powerplant by construction of a 357 meter long (1,170-foot), 61 meter high (201 foot) forebay dam along the right abutment approximately parallel to the river and at an angle of 64 degrees to the axis of Grand Coulee Dam. The total length of the main dam, forebay dam, and wing dam is 1,592 meters (5,223 feet). The spillway of the dam is controlled by 11 drum gates, each 41 meters long (135 feet), and capable of spilling 28,320 cubic meters (1 million cubic feet) of water per second with Lake Roosevelt at full pool (393 meters (1290.0 feet) above sea level). The dam also contains forty 259 centimeter diameter (102- inch) outlet tubes. Within the dam are 13 kilometers (8.5 miles) of inspection galleries and 4 kilometers (2.5 miles) of shafts. The power facilities at Grand Coulee Dam consist of a powerplant on both the left and right sides of the spillway on the downstream face of the dam, the Third Powerplant, on the downstream face of the forebay dam, and the John W. Keys III Pumping-Generating Plant on the left abutment of the dam. Total powerplant capacity is 6,809 Megawatts.

Who Should Attend The seminar is designed for managers, administrators, engineers, and geologists responsible for the design, construction, operation, maintenance, and safety of dams. Policymakers and planners, as well as those with technical responsibilities, may also benefit from the seminar. All presentations, discussions, and printed materials will be in the English language. Participants should have a good command of general and technical English usage.

Costs and Registration The registration fee is US $4300 per person. Various printed and electronic materials, lodging for 11 nights (August 14-24), breakfast, most lunches, and transportation during the study tour is included. Hotel accommodations will be arranged by Reclamation, and participants are expected to stay in selected hotels. Any miscellaneous costs such as laundry, telephone, usage, etc., will be at the participant's own expense.

It is strongly recommended that individuals apply as soon as possible for visas and seek sponsorship, if necessary. Funding is not available from the seminar organizers. Please submit a legible copy of your passport with your registration form.

Payment should accompany the registration form. Checks should be in U.S. dollars and made payable to the Bureau of Reclamation. Credit card payments, which is the preferred method of payment, and wire transfers are acceptable (see registration form). The registration form must be received before August 5, 2011. Due to contractual arrangements with hotels and airlines, any registration forms received after August 5, 2011, will incur a registration fee of $4,600.

International travel should be arranged into Denver, Colorado, no later than Sunday, August 14, 2011, and out of Spokane, Washington, no earlier than Thursday, August 25, 2011.

Climate/Clothing Suggestions/Medical Insurance Participants should expect warm days and cool nights whereby a light-weight jacket may be necessary. Casual clothing and work boots/sturdy closed-toed shoes are required on field tours. Accidental injury/medical emergency insurance is strongly recommended and should be purchased prior to traveling to the United States. Reclamation is not financially responsible for any illnesses or injuries that may be incurred by participants. Please refer to the following website for reference: http://www.medexassist.com/Individuals/Projects/travmedchoice.aspx