LIFELINE ENGINEERING AND THE CREATION OF ALA

The engineering community has long worked to build safe and reliable lifeline systems -- that is, those systems necessary to provide electric power, natural gas, water and wastewater, and transportation facilities and services that are essential to the well being of the community served by these systems. Providing lifeline system function is especially important in assisting rapid recovery following natural hazards. Engineering approaches to limiting damage to lifeline systems from natural hazards have developed specifically for individual natural hazards and individual types of lifeline systems. Thus, the design of electric power transmission systems focused on loads from high wind and ice storms, while the design of natural gas transmission systems focused on landslides and fault crossings.

Using a system-based approach to assessing expected lifeline function is a relatively recent development that was largely driven by the need to prioritize efforts to improve system performance for large earthquakes capable of generating multiple hazards throughout the system. The consequences on a community that experiences simultaneous disruption of multiple lifeline systems were demonstrated during earthquakes in the US, particularly the 1906 and 1933 events in California. The severe effects of these earthquakes spurred the initial development of seismic design requirements in buildings and other structures in California. Unfortunately, lessons on the need for rapid restoration of lifeline function to aid in community response to earthquakes waned as a result of a lack of significantly damaging urban earthquakes for nearly four decades after 1933. Following the 1971 San Fernando earthquake - an event that caused catastrophic damage to virtually every type of lifeline - many new efforts were launched to better understand the causes of these failures and identify ways to mitigate future earthquake damage and disruption.

The post-1971 lifeline earthquake engineering efforts have consisted of engineering research at academic institutions and the development of improved industry practices along with local or regional regulatory requirements. These efforts have been effective in reducing lifeline earthquake risks for some lifeline systems in some areas of California and the West Coast. In particular, the importance of understanding overall system functionality, instead of just the response of isolated components, has been recognized as a key concept in developing an effective earthquake risk management program for lifeline systems.

However, identifying lifeline system risks and implementing measures to improve earthquake performance have not been uniformly carried out even in coastal California, where the seismic hazard and population density are both relatively high. In lower-hazard parts of the United States, implementation of earthquake risk management has been varied and sporadic. In particular, there has been limited progress in developing and implementing consensus guidelines and standards to provide consistent improvements in the performance of new and existing utility and transportation systems in large earthquake events across the United States.

In 1998, the Federal Emergency Management Agency (FEMA) and the American Society of Civil Engineers entered into a cooperative agreement to establish the American Lifelines Alliance (ALA) to facilitate the "creation, adoption and implementation of design and retrofit guidelines and other national consensus documents that, when implemented by lifeline owners and operators, will systematically improve the performance of utility and transportation systems to acceptable levels in natural hazard events, including earthquakes." Inclusion of all natural hazards in the scope of ALA recognizes the benefit of managing the risks from multiple potentially damaging natural hazards events in a balanced fashion that meets the objectives of the lifeline owner or operator for lifeline functionality and the needs of their customers who rely on the lifeline services. Decisions on where to devote resources for improving lifeline system performance should be prioritized by considering the likelihood of experiencing natural hazard events, the impact of the natural hazards on the system, and the value of improving system performance to the owners of the system and their customers. Accordingly, the need to implement system improvements that address specific natural hazards will vary depending on the likelihood and severity of natural hazards and on the operational characteristics of the system.

Following the terrorist attacks on September 11, 2001, the scope of ALA was expanded to include man-made hazards. This change is consistent with the broader goals of FEMA and recognizes that actions that minimize the effects of natural hazards also can improve resistance of structures and systems to man-made hazards. In late 2002, FEMA brought ALA under the Multihazard Mitigation Council through a partnership with the National Institute of Building Sciences.