Historically, concrete dam analysis focused much of the attention on material property assumptions, which has been and continues to be important. But more recently, the focus is primarily on the modes of failure experienced by these types of dams. This webinar will present a more in-depth review of stability evaluation methods for concrete dams; the basics of which was first presented in the previous webinar entitled “Introduction to Co...

Labyrinth weirs are widely used in spillway rehabilitation to upgrade existing dams to meet updated spillway design flood criteria. In addition to increasing discharge capacity, these weirs are also well suited to regulating upstream pool elevations for flood control or at intake structures. The hydraulic design of a labyrinth spillway requires the consideration of complex flow characteristics and optimization of multiple geometric parameters...

Notice: For this special webinar for dam owners and operators, the discounted fee of $50 provides access to the archived recording of the webinar, and does not include a quiz or certificate for professional development hours (PDHs). This seminar provides an introduction to inspecting and evaluating dams. The target audience is dam owners and personnel responsible for the operation and maintenance of dams. The principles, concepts and procedur...

This webinar will focus on the many applications of RCC in dam engineering, including RCC dams, RCC overtopping protection, and RCC use in cofferdams. Other topics to be covered will be RCC for raising and rehabilitating existing concrete dams and RCC for grade control structures and stilling basin erosion protection. Emphasis will be placed on small to medium volume RCC projects including hints on cost effective design and and estimating. In...

This webinar provides an introductory discussion of the processes governing earth and vegetated earth spillway design and performance. Topics include the history of vegetated earth spillway use by the USDA and the associated design criteria, the concept of stability and integrity design, the importance of maintenance, and the erosion processes quantified in the SITES program. Examples from USDA NRCS experience and USDA ARS research will be use...

Physical models have been used as part of the design process for spillways and other hydraulic structures for centuries. Their use has proven to be extremely effective for validating hydraulic design schemes for new and rehabilitated spillways, for the discovery of hydraulic design problems that previously had not been expected, and in reducing construction costs. Physical modeling is also important for public relations, for reducing risk and...

With the development in Europe in the later 1800s of a rational method for evaluating structural stability combined with practical experience, U.S. engineers gained greater confidence in increasing the structural height and loadings on masonry dams, as they were known then. This lead to record setting heights in the U.S. for several gravity dams built for water supply purposes for major U.S. cities. As records were being set, a few dramatic co...

The Webinar will have four ½ hour sessions and will begin with a brief review of the Hydraulics 101 Lectures. Uniform flow, specific energy, and gradually varied flow will be covered in the first session. Hydraulic modeling and water surface profile computations will be covered in the second session and geometric data requirements will be addressed in the third session. The final session will concentrate on the development of the Hydro...

Probable Maximum Precipitation (PMP) is used to compute the Probable Maximum Flood (PMF) that in turn is used by federal and state regulators to evaluate the safety of dams. The concept of an upper limit for precipitation was presented in the 1940’s with procedures for determining PMP values developed by the Weather Bureau (now the National Weather Service), the US Army Corps of Engineers, and the Bureau of Reclamation. The definition o...

The Hydrology 201 Webinar consists of four one-half hour segments. The first segment is a brief review of Hydrology 101 emphasizing some of the important hydrologic issues. The second segment will concentrate on the NRCS procedures to determine the loss rate function and the dimensionless unit hydrograph as it is utilized to transform excess rainfall into runoff. Different methods of determining time of concentration and lag time will be cove...