Dam Safety Programs in Costa Rica and El Salvador

On October 29, 1998, Hurricane Mitch touched down in Central America, becoming one of the most devastating storms to hit the western hemisphere in 200 years. The storm took the lives of over 11,000 people with total damages in the order of U.S. $5 billion. For many utilities, the flooding associated with the hurricane revealed serious flaws in the ability of the flood control dams to operate during emergency conditions. Furthermore, in some cases where the flood waters passed through the control structures, the result was unexpected flooding of many downstream communities due to a lack of standardized procedures and emergency preparedness plans.

In the aftermath of the hurricane, the state utilities of Costa Rica and El Salvador set the ambitious goal of developing, and then implementing, state of the art dam safety standards and dam safety assessment programs to minimize future risks. The utilities requested assistance from the PREEICA project, which is a consortium that provides state of the art engineering services to the region. It is funded by the Canadian International Development Agency (CIDA) and involves Acres International, SNC-Lavalin and Manitoba Hydro. For this assignment, Acres was asked to undertake the work.

Under the PREEICA concept, all projects follow a work plan with the primary goal of training local utility staff so that the expertise will be available for the long-term benefit of the country.

Acres mandate was twofold. First they had to define appropriate dam safety standards and regulations, and define who the regulators would be. Second, they were asked to develop appropriate dam safety assessment procedures and train local staff in the performance of such assessments. In short, the assignment involved transferring nearly three decades of Canadian dam safety experience to Costa Rica and El Salvador within a one-year window.

In the first phase of the project, Acres senior dam safety consultants held meetings with both utility staff and regulators to develop standards and procedures that met with the societal expectations of each country. Acres then set up an organizational framework to enable the new standards to be implemented and administered.

For the training process, Acres worked with their utility counterparts to do safety inspections of all the major dams in each country. Rotating groups of operations and engineering staff from the utilities accompanied the Acres specialists. As a result, more than 50 people received hands-on training.

The exercise helped the local utilities, both to develop in-house skills, and to identify real dam safety problems that had been previously unknown. The staff were trained hands-on in the performance of dam safety studies and came to understand dam safety concepts. They used technologies such as three-dimensional dam stability assessments, hydrotechnical analyses, and state of the art dam break simulations. Their introduction to modern techniques in dam break simulations is particularly important for enabling them to define appropriate warning schemes for any future emergency.

Acres staff also helped the utilities with emergency preparedness plans. Given the absence in Costa Rica and El Salvador of strong national emergency coordination bodies to take the lead in responding to an impending disaster, Acres tailored the utilities’ emergency preparedness plans. Where the utilility is present in an affected area, their plan could be used to alert the local government authorities and general public.

In order to complete all the objectives and interrelated tasks within the one-year time constraints of the project, efficient management and facilitation skills were essential. Acres held workshops, classroom-type instruction, field and office assessments and facilitated meetings. The project’s overall complexity was increased by the need to have all documents and meetings in Spanish and English.

An important by-product of the assignment was the dam safety issues that the Acres/utilities team uncovered during the site inspections. The latest techniques in engineering, seismicity, geotechnical and hydrotechnical analysis had to be used to solve these and other problems. The implementation of the solutions has already commenced, reducing the risks to the public, the environment and the utilities themselves.

All the objectives were achieved on time and on budget. Dam safety standards are now in place in both countries, and the reports that Acres prepared are models for the dam safety assessments that will be performed. The project will provide long-lasting benefits to both nations.

Throughout North America and around the world, dam owners are facing increasingly difficult decisions about the ways in which finite financial and human resources should be allocated to ensure the continuing safe operation of ageing dams. Without such investment, dam failure is not only a possibility but can be an expected consequence where there is a lack of proper maintenance and diligence by a dam owner. Since this project was completed, Acres has been asked by other countries, such as Iran and China, to provide similar assistance. The spread of the concept of dam safety across the globe has real environmental and public safety benefits. Canada continues to enhance its stature as a world leader in this field.

Name of project: Dam Safety Programs in Costa Rica and El Salvador

Award-winning firm: Acres International, Niagara Falls, Ontario, member of PREEICA Consortium (R. Fletcher, P.Eng., R. Donnelly, P.Eng., D. McAndrew, P.Eng., S. Rigbey, P.Eng., M. Davachi, P.Eng., R. Morais, P.Eng., D. Sanchez, P.Eng., C. May, P.Eng.)

Owner: Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL); Instituto Costarricense de Electricidad (ICE)

Client: Canadian International Development Agency