Changing demographics in the vicinity of dams have led to hazard creep in a number of dams worldwide. Many of these dams now have insufficient spillway capacity as a result of these changes in hazard classification from low to significant or high hazard. Stepped chutes applied to the embankment dams offer an advantage by providing increased spillway capacity. This webinar provides an overview on stepped chute research conducted at the USDA-Ag...

Failure mode evaluation or what now is more commonly referred to as potential failure mode analysis (PFMA) for dam safety has become routine practice for many in the profession. The process became more formally organized by the US Bureau of Reclamation in the early to mid 1990’s and gained wider industry exposure in the early 2000’s through the publication of FERC’s Engineering Guidelines, Chapter 14 – Dam Safety Perfor...

This webinar covers the use of sand and gravel filter/drainage systems in embankment dams to protect against excessive seepage pressures, internal erosion in cracks or other anomalies, and piping. Excessive seepage pressures can affect embankment stability related to slope sloughing or failure and piping from progressive removal of soil forming a tunnel feature in or under the embankment. Many seepage issues in dams involve the development of...

This webinar will provide participants with information on the importance of preparing operations and maintenance (O&M) manuals for dams. It will include an overview of some of the key federal agency and state requirements and formats for dam O&M manuals. Operations and maintenance guidelines will be presented for both embankment and concrete dams and key dam appurtenances, such as spillways and outlet works. Many examples will be prov...

Quality control on projects for the construction or rehabilitation of dams is the responsibility of the construction contractor. Contractors have control of the site during construction and are responsible for understanding and complying with the requirements of the contract documents. It would be remiss on the part of the owner however, to solely rely on the contractor for this task. To verify contract compliance, construction of complex and...

This webinar is designed to provide dam and levee owners, and their specialist consultants, an introduction to a comprehensive program to assess and reduce public safety risk around dams, levees and powerhouses. In 2011 the Canadian Dam Association, an association similar in nature to the ASDSO, published “Guidelines for Public Safety Around Dams”. Dam owners across Canada are embracing these Guidelines and are assessing and reduc...

Earthquakes represent a hazard to dams in many parts of the United States and therefore are of interest to design engineers and dam safety officials. The hazard from earthquakes includes strong shaking, fault rupture displacements, reservoir seiche and earthquake-induced landslides, all potentially damaging to dams and reservoirs. This webinar will discuss the physics and geology of the earthquake process and the methods used to identify seis...

This webinar is the third and final course in the series on Concrete Gravity Dams. The first webinar entitled “Introduction to Concrete Gravity Dams” (July 2012) presented information regarding the types of gravity dams, historic design and construction practices as well as lessons learned from noteworthy gravity dam failures. The second webinar in this series entitled “Stability Evaluations for Concrete Dams” (Oct. 20...

This webinar will address a wide range of foundation preparation and treatment methods applicable to construction of new dams, rehabilitation of existing dams, and enlargement of existing dams. Topics to be covered include: 1) treatment of surface rock exposures in dam foundations, 2) rock grouting, 3) treatment of foundation soils, 4) foundation seepage barrier walls and upstream blankets, and 5) foundation seepage collection and control methods.

Some amount of seepage passes through and under all embankment dams. The collection, monitoring, and analysis of seepage is crucial in the successful execution of any dam safety program and is helpful in deciding if it is expected ambient seepage or indicative of a more serious condition. Seepage collection methods typically include toe drains, blanket drains, and relief wells. Monitoring schemes can be grouped into several categories includi...