Dams are part of human achievements that induce great benefits for society but also bear a potential risk to people, property and the natural environment. The risk of a dam rupture is extremely low and diffi cult to quantify accurately. The aim of ‘Dam surveillance’ (ICOLD Bulletin 158), is to help reduce these risks by early detection of an undesirable event. The objective of dam surveillance is to make a precise and timely diagnosis of the behavior of dams, in order to prevent undesirable consequences. Both the monitoring system and surveillance program has to be designed and should be able to detect any abnormal behaviour. ‘Dam surveillance’ (ICOLD Bulletin 158), emphasizes the following aspects: • Routine visual inspection • Special inspection • Checking and testing of Hydro-electromechanical equipment • Monitoring parameters and devices • Automation • Maintenance of ageing monitoring systems • Re-instrumentation of existing dams • Recent developments • Data management • Dam documentation management • Assessment of dam condition and behaviour • Assessment of routine dam safety monitoring programme • Prioritization of maintenance, remedial and upgrading works.

Dams are part of human achievements that induce great benefits for society but also bear a potential risk to people, property and the natural environment. The risk of a dam rupture is extremely low and diffi cult to quantify accurately. The aim of ‘Dam surveillance’ (ICOLD Bulletin 158), is to help reduce these risks by early detection of an undesirable event. The objective of dam surveillance is to make a precise and timely diagnosis of the behavior of dams, in order to prevent undesirable consequences. Both the monitoring system and surveillance program has to be designed and should be able to detect any abnormal behaviour. ‘Dam surveillance’ (ICOLD Bulletin 158), emphasizes the following aspects: • Routine visual inspection • Special inspection • Checking and testing of Hydro-electromechanical equipment • Monitoring parameters and devices • Automation • Maintenance of ageing monitoring systems • Re-instrumentation of existing dams • Recent developments • Data management • Dam documentation management • Assessment of dam condition and behaviour • Assessment of routine dam safety monitoring programme • Prioritization of maintenance, remedial and upgrading works.

Hydrology and dams are two fields that are obviously closely related. Four bulletins have so far been published by the Committee: Selection of Design Flood – Current methods, Dams and Floods – Guidelines and cases histories, Role of Dams in Flood Mitigation – A review and Integrated Flood Management. These bulletins have essentially addressed floods, the risks they represent and their significance for the concerned populations. The present Bulletin deviates slightly from this path, adopting a somewhat more technical perspective. The text consists of three chapters, conceived to be accessible to the practitioners.

Dam decommissioning or dam removal has been increasingly common since the past decade. The reason for considering dam removal may have to do with the safety of dams, high repair costs, high operating and maintenance costs, or effects on fish passage and water quality. However, the decision to remove a dam must be based on careful evaluation of the alternatives to address the specific problem at each dam. The ICOLD Committee for decommissioning dams was established in 2005 to develop information that can be used by ICOLD members to respond to questions about the dismantling of dams and to provide a forum for the exchange of information . This ICOLD Bulletin is not intended as a design guide, but as a guide to the decision making process, consultation and regulatory approvals, design and construction issues, sediment management and performance monitoring. The primary aim of these Dam decommissioning guidelines is to provide dam owners, dam engineers and other professionals with the information needed to guide decision making when considering dam dismantling as a project alternative. They are not meant to be used as a design guide, but as a guide to highlighting the points of interest. The guidelines in this ICOLD Bulletin apply only to flood defense structures and not to fall dams.

This book addresses current international practices applied for dam safety assessments by looking at a portfolio of dam safety projects in various developing countries (Armenia, Georgia, Tajikistan, Mauritius, Madagascar, Sri Lanka, Myanmar and Vietnam) spread across three continents (Europe, Africa and Asia). Safety assessment involved the review of 134 existing dams and comparison with the best international practices. A large part of dam safety assessment involves understanding of dam hazards, standards applied in the design and maintenance, as well as expectation and social circumstances under which the dams have been designed and constructed in a particular country. For example, standards for design floods, ground investigation, selection of design soil parameters and design earthquakes etc. used are often either non-existent or inadequate, which could lead to an unsafe design. If there are no standards to be applied in dam design and construction, consultants are often under pressure from clients to come up with minimalistic investigation and designs, which, after a few years after dam construction, show signs of deficiencies. Very often countries have no regulations and standards for requirements that should cover the maintenance and operation of dams. The book also describes the Portfolio Risk Assessment of Dams, which can be used as a tool by clients and the funding agencies to identify priority assessment and rehabilitation projects that consider societal and economic losses. It also demonstrates how the implementation of Emergency Preparedness Planning could significantly reduce the number of people at risk. This book aims to help clients, consultants and funding agencies which are engaged in dam safety assessment projects in developing countries to focus on issues that are based on past lessons learnt.

MOP 135 provides practical information on the process of using instrumented monitoring to determine how well a dam is performing.

"Examines the dam safety regulatory frameworks of 22 countries" and "identifies essential elements, desirable features, and emerging trends for dam safety regulatory frameworks." - cover.