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Early Warning System for Dam Hazards

The Vanguard Foundation and LIRNEasia in collaboration with Sri Lanka National Committee on Large Dams, Sarvodaya, ITDG South Asia and with the support from Canadian International Development Assistance had launched this project to enhance the awareness of the Government authorities, civil organizations and other stakeholder communities on the need to introduce a hazard warning system for dam related disasters. For this purpose a concept paper and a video documentary were produced.

At a media event on January 2003, 2006, Prof. Rohan Samarajiva, Executive Director of LIRNEasia, handed over the final Concept Paper for a Dam-related Hazard Warning System in Sri Lanka: A Participatory Study on Actions Required to Avoid and Mitigate Dam Disasters [PDF download] to U. W. L. Chandradasa, Director, Disaster Management Centre, Government of Sri Lanka. Excerpts from Kantale: 19 Years Later, a video documentary that was directed by Divakar Goswami and produced as part of the dam hazard project was screened on this occasion.

Concept Paper for a Dam-related Hazard Warning System in Sri Lanka: A Participatory Study on Actions Required to Avoid and Mitigate Dam Disasters
By Rohan Samarajiva, Divakar Goswami & Rebecca Ennen

Executive Summary

1.1 The dam network in Sri Lanka comprises over 350 medium and large dams, and over 12,000 small dams. Today, dams and their complementary structures shape Sri Lanka much as they did thousands of years ago. Maintenance, safety oversight, and usage rights are shared among several Ministries, Authorities, organizations, and informally stake holding nearby populations. This is natural given the multiple uses of, and demands placed on, the dam system. However, there is a great need for improved oversight of the dam system and the proper coordination of functions, especially related to safety.
1.2 Among the possible negative outcomes of under funding of and lack of emphasis on dam asset management (including operation and maintenance) are catastrophic failures of dams resulting in loss of life and property damage to the environment, affecting the well-being of the community including loss of the benefits provided to the dam. These negative outcomes can be caused by the incorrect or lack of proper operating and maintenance procedures, and lack of maintenance and required upgrades to relatively new or ageing dams, minimal education of vulnerable populations on the risks and responsibilities of those living in the shadow of dams, and poor disaster response plans. Most seriously, it appears that inadequate priority is being given to the proper maintenance and periodic upgrades of dam structures, and that the existing financial arrangements are quite unsatisfactory. Given the number and widespread distribution of dams in Sri Lanka, it is clear that the affected populations and sectors are many, and that the effects of dam-related hazards can be very serious. In the opinion of the experts the current financial, operational and regulatory arrangements are unlikely to prevent the occurrence of dam-related disasters and may even contribute to them.
1.3 The key to effective dam safety is an adequate and properly resourced dam safety program that ensures:
1.3.1 That the dams are operated and maintained in a safe manner (that correct standing operating procedures for normal operation and maintenance and emergency operating procedures are in place to manage emergencies and these procedures are reviewed annually). Operators must be trained and competent.
1.3.2 That the nature of the hazard posed by each dam is known and regularly reviewed (Dam break studies are done and the population at risk identified and possible damage to property and other infrastructure identified and costed). The hazard category of each dam must be identified.
1.3.3 That dam surveillance programmes appropriate for the hazard category are implemented.
1.3.4 That dam safety emergency plans are prepared and where appropriate warning information and inundation maps are provided to emergency response agencies to assist in downstream emergency planning and response by these agencies.
1.3.5 That appropriately qualified, trained and experienced personnel are engaged on dam design, construction, operation and maintenance and on dam inspections and surveillance.
1.3.6 That suitable regulatory and governance structures and internal reporting procedures are in place.
1.3.7 That dam safety reviews are undertaken at the appropriate time (despite appearance of invulnerability, dams do age with time. The design bases on which they were designed will also change with advances in knowledge and technology. Hence comprehensive reviews of the structural, hydraulic, hydrological and geotechnical design of dams and their behaviors (through records of operation and maintenance and surveillance records) should be undertaken.
1.3.8 That dam safety risk assessments are undertaken and risks addressed on a priority basis (by required dam upgrades).
1.3.9 That the dam safety program be quality assured by periodic independent review.
1.3.10 That includes making the public aware of dams and dam safety issues and consulting the public about their concerns.
1.4 Early detection of signs of distress is critical to effective dam safety. If the weakening of the structure is detected very early, remedial measures may be taken to repair it and prevent it from becoming a hazard. Even if the detection of structural problems occurs relatively later, action may be taken to mitigate its effects, for example by lowering water levels. Even if it is detected a few hours prior to a breach, that would still allow for action to save lives and property.
1.5 It is accepted that human observation and judgment is critical to effective dam safety programs. But this must be supported and complemented by modern instrumentation. At present, dam hazard detection and monitoring devices are not in wide use in Sri Lanka, the most common methods being simple visual inspections conducted for the most part by inadequately prepared, lower-level staff. The Kantale dam was visually inspected six months its breach to no avail. The actual breach was detected by a villager. The most advanced equipment was installed at Lunugamvehera, one of the most recent large dams, but they have not been maintained in optimal condition subsequently. It is recognized that the sophistication of the instrumentation must correspond to the level of risk that exists.
1.6 While recognizing the costs and maintenance implications of state-of-the-art dam hazard detection and monitoring equipment, this Paper suggests that it may be worthwhile to conduct at least two pilot projects using advanced dam hazard detection and monitoring equipment coupled with advanced information and communication technologies that would enable the data to be monitored in multiple locations including the dam’s own control facility.
1.7 Even if advanced detection and monitoring systems are adopted, it is essential that the staff, the villagers and others who live by and frequent the dam area are trained to look for signs of impending hazards.
1.8 Hazard detection and monitoring information must be interpreted by skilled professionals in order to generate disaster alerts and warnings. Given the short time periods that may be available and the importance of site-specific knowledge, the responsibility for issuing alerts and warnings must reside within the dam operator, preferably with the engineer responsible for the dam. ICTs may be used to provide the decision maker with back up expertise.
1.9 It is critically important that engineers in charge of major dams and their technical staff be provided with modern communication equipment and that they are exempted from government regulations inimical to use of fixed telephones above a cost threshold. Mobile telephone use should be encouraged with cost reimbursements.
1.10 Last mile dissemination of disaster alerts and warnings should be well planned, with multiple redundant media and channels, ranging from cell broadcasts that will be limited to coverage areas of specific base stations to use of mosque loudspeakers and temple bells. Training, drills and community participation are crucial to the success of last mile dissemination.
1.11 It has been found that unsatisfactory financial arrangements, wherein dam operators supply valuable services but cannot recover their costs, contribute to the systemic problems of neglecting or postponing major and ongoing maintenance work. It is essential that an effective mechanism for reliable, predictable cost recovery that is exclusively devoted to maintenance is devised and implemented.
1.12 The government should establish a regulatory body with dam safety as its primary objective, separate from and superior to, each of the entities currently owning, operating, or using dams. It should give priority to expertise and stakeholder consultation and be insulated from day-to-day political interference. In other words, it should be independent. The current difficulty of a lack of power over peer government agencies can only be resolved by placing the dam safety functions within an organization that is accountable to Parliament and is not under a specific Minister.
1.13 The Dam Safety Management Unit (DSMU), which contains specialized NEWS:SL [National Early Warning System: Sri Lanka] expertise on dam hazard detection and monitoring, can be placed within either the Public Utilities Commission, which already has some safety regulation functions, or the proposed. The larger organization will give the necessary stature, authority and independence; the focused unit structure will allow the experts to conduct their business in a professional manner.
1.14 The removal of immediate dam safety responsibilities from the persons and organizations currently in charge of the reservoirs is not proposed in any way. Those who are closest to the potential hazard-generating structure and who have the best knowledge of it must continue to perform those functions. The mandate of the DSMU should be explicitly limited to regulation, alternative dispute resolution and related practices to minimize and promptly resolve interagency disputes, and standard setting.
1.15 In order to enforce its directions and orders, the DSMU and its parent organization should have the power to shut down structures that are judged to pose an unacceptable risk and where the owners have not followed directions, using carefully circumscribed procedures and definitions that allow for optimum publicity and which adhere to the principles of natural justice.

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