Technical Updates on Dams

The International Commission on Large Dams (ICOLD) calls producing technical bulletins the “heart” of its activity. Learn about the upcoming congress and annual meeting, as well as some highlights of the content of four bulletins released in 2017.

The European capital city of Vienna, Austria, located on the Danube River, is the backdrop for the International Commission on Large Dams’ 26th Congress and 86th Annual Meeting.

Although it is known as The City of Music or even The City of Dreams, Vienna seems also to be a fitting location for a meeting of an organization that is devoted to “advancing the art and science of dam engineering and promoting the wise and sustainable development and management of the world’s water and hydropower resources.”

The ICOLD annual meeting was previously held in Vienna in 1991 and 1938.

Dr. Anton J. Schleiss, president of ICOLD, said Austria is an important hydropower producer in the Alps, with significant storage capacity. “Until today, 171 large dams have been put in operation with four dams higher than 150 m,” he said. “Austria has developed and is still developing its hydropower resources in an exemplary and sustainable way. The valleys of most of the dams have become touristic attractions in winter as well as in summer.”

As Austria’s Federal Minister for Sustainability and Tourism, Elisabeth Kostinger, explains, “Since 1991, when the last ICOLD Congress took place in Vienna, the economic situation in the field of dam construction as well as the environmental background has changed significantly. Besides the liberalization of the European Electricity Market, the increasing use of wind and solar energy led to a fundamentally different management of our hydro power reservoirs. The flexibility of hydro power technique gives the possibility to compensate and equilibrate the large electricity load peaks in the European Power Grid. With the increasing but heavily oscillating energy production out of renewable, alternative energy, the storage and compensation by hydro power energy with its quick stand-by duty gets more and more importance.”

Kostinger cites the 450-MW Kops II (or Kopswerk 2), 360-MW Obervermuntwerk II and 480-MW Limberg II as examples of hydroelectric plants built in the past 10 years in Austria that allow the country to play a major role in the areas mentioned above. Kostinger also says the country has worked over the past two decades to ensure a high Austrian Dam Safety Standard for high-hazard reservoirs.

“A great number of national institutions, the dam owners and the members of ATCOLD [the Austrian National Committee on Large Dams, or ATCOLD, host of the event] are looking forward to contributing to ICOLD, supporting the Congress in Vienna. Our aim is a productive get together for our community based on hospitality and friendship,” said Gerald Zenz, ATCOLD president.

Content of the annual meeting and congress

The 86th Annual Meeting and 26th World Congress runs from July 1 through July 6. The host is the Austrian National Committee on Large Dams.

On Sunday, July 1, 28 technical committees will meet, with about 500 technical experts contributing to help produce technical bulletins, which ICOLD calls the “heart” of its activity (see Technical Bulletin Highlights subhead for more information).

Technical committee workshops will take place on July 2, with new committees meeting at the beginning of their terms of reference to refine these and the working program and technical committees approaching the end of their terms meeting to discuss the draft bulletin produced with a wider audience to enhance knowledge transfer.

The ATCOLD Hydro Engineering Symposium will start on July 2. The intention of this symposium is to offer presentations and discussions on specific issues of hydraulic structures serving for energy from renewable resources, irrigation, drinking water supply and flood protection. This symposium focuses on five topics: climate changes reservoir operation, permission and safety assessment, dam and foundation sealing, caverns and power waterways, and stability of reservoir slopes. This symposium features a special session on the situation at Oroville Dam in California, U.S., including the repair work and specifics on the forensic report.

In addition, ICOLD’s annual meeting features a technical exhibition – which opens July 2 – with more than 90 consultants, contractors and suppliers.

The event features a technical excursion on July 2 to the Vienna-Freudenau power plant, the most recent power station on the Danube River. The powerhouse contains six Kaplan turbines, and the facility began operating in 1998.

The ICOLD World Congress, which is held every three years, provides an opportunity to discuss four special topics/questions on a worldwide perspective. For 2018, these are:

– Reservoir Sedimentation and Sustainable Development, chaired by George Annandale

– Safety and Risk Analysis, chaired by Harald Kreuzer

– Geology and Dams, chaired by Kaare Hoeg

– Small Dams and Levees, chaired by Adama Nombre

Each question will be introduced, with the general reporter summarizing, highlighting, and concluding the contributions. Each general report is accompanied by four sessions of two hours on subtopics and related aspects, with time allocated for discussions and exchange of experiences.

In addition, several study tours will start on July 7. These five study tours take interested attendees to multiple dams and hydro stations, as well as other attractions of interest, over three or four days. Dams and hydropower plants included in various study tours include the Lehen plant in Salzburg, the Wasserfallboden and Mooserboden reservoirs at Kaprun, Kops and Obervermuntwerk, the Prutz Tiwag power plant, the Koralpe Lavamund power station, and the Gstatterboden Lake power plant.

Technical bulletin highlights

If traveling to Vienna, Austria, this July is not in the cards, ICOLD offers other opportunities to access valuable information from the global dams community.

One of these is its technical bulletins, mentioned earlier. “On a single precise subject, our experts have met during three to five years and they produced a state-of-the-art with recommendations from engineers from all over the world,” ICOLD says. Committees are formed for the purpose of developing these bulletins and typically have specific terms of reference. Current committees run the gamut from climate change to hydromechanical equipment to resettlement due to reservoirs.

To date, ICOLD has published 157 technical bulletins. Recently, ICOLD released four technical bulletins on a variety of topics of interest to those who work with dams and civil structures.

Below is information on each of these bulletins, which are available for purchase (prices vary) at http:// www.icold-cigb.org/GB/publications/bulletins.asp.

Bulletin 168: Recommendations for Operation, Maintenance and Rehabilitation

The need for proper operation and maintenance is of crucial importance for developing countries’ organizations, which may have, at present, limited experience. The aim of this bulletin is to offer the possibility to benefit from the experience of other organizations or countries.

It is also a fact that our dams are aging and one day, or another, owners will have to face the issue of rehabilitation or adapting to new operating conditions.

The purpose of this bulletin is not to define the proper organization or procedures, but to open the eyes of newcomers either to plan for the future of their new dam or to assist them to solve problems they may experience with their existing dams today.

Bulletin 164: Internal Erosion of Existing Dams, Levees and Dikes, and their Foundations

Internal erosion is one of the major causes of embankment dam failure.

When constructing new dams, protection against internal erosion is provided by zoning and by providing filters. However, many existing dams are not adequately zoned and do not have filters and may therefore be vulnerable to internal erosion. Others have filters not designed and/or constructed to modern standards, and they too may be vulnerable to internal erosion.

The bulletin is in two volumes.

Volume 1 deals predominantly with internal erosion processes and the engineering assessment of the vulnerability of a dam to failure or damage by internal erosion, with a brief oversight of monitoring for and detection of internal erosion and remediation to protect dams against internal erosion. It includes a comprehensive listing of the terminology used in internal erosion. Many references are also given.

Volume 2 gives more details of internal erosion investigations and appropriate testing, monitoring and detection, and remediation, and gives case histories.

Bulletin 154: Dam safety management: Operational phase of the dam life cycle

This bulletin is devoted to the development and the implementation of a dam safety management system for dams in the operational phase of their life cycle. It outlines the general structure of a systems approach to safety management and strives to develop a system that can address all the interdependencies and encompass all the arrangements necessary to ensure proper dam safety management.

The bulletin is intended to be helpful in developing, implementing, reviewing and improving the management of dam safety at all organizational levels.

Bulletin 151: Tropical residual soils as dam foundation and fill material

Dam construction across the world has recently acquired an accelerated pace as needs for water supply and renewable energy sources have increased in many countries. Many of these countries are located in areas where tropical residual soils are abundant.

The main difficulty in dealing with these soils for engineering purposes is that their characteristics are very different from those of transported soils.

ICOLD says the purpose of this bulletin is to illustrate how these materials have been accepted and used in dam projects without imposing selection of better known materials that could jeopardize the economic viability of a project.

Elizabeth Ingram is managing editor of Hydro Review.