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Resilient Design Performance Standard for Infrastructure and Associated Buildings for Boulder County

Steve Moddemeyer, Principal and Chris Poland Consulting Engineer collaborated with the Boulder CDBG-DR Collaborative to develop a Resilient Design Performance Standard for infrastructure and associated buildings. This helped the communities to set recovery times for infrastructure based on community priorities. The process revealed dependencies and interdependencies between infrastructure systems that would otherwise delay achieving the community’s goal of recovery. It also developed guidance for infrastructure design teams to consider and document consideration of socio-ecological resilience into the infrastructure design process.

Including recovery time as a performance metric is an essential element in resilience planning. Yet it is not common. Most infrastructure providers base their standard for project design on a probabilistic reliability standard to resist events of a certain magnitude, such as the 100-year storm (a one percent chance of an event in any given year based on analysis of the climate record). Yet what happens after that threshold is crossed is too often ignored in the design process.

It shouldn’t be. Here’s why. Basing design solely on resisting events of a certain size works reasonably well when the climate is stable or when the failure of one infrastructure systems doesn’t spill over onto other community functions. Yet all indications are that the climate is no longer stable and the last 100 years of weather measurements no longer provide defensible probabilistic measures of the likelihood of exceedance. In practice failure of one mode of infrastructure may impact other modes just as much or more. That means that infrastructure systems are more likely to be pushed beyond their design parameters resulting in more failures, lower reliability than promised with increased time and cost for recovery. Because the time and cost of recovery is not typically considered in project design and evaluation, then these extraordinary costs are treated as externalities that fall onto infrastructure providers, local governments, community groups, local businesses, regional businesses, and homeowners who survive the event. They are left holding the bag as they must navigate through the delays, work-arounds, and inconvenience of a recovery period that can last months and even years. For larger disasters the length of the recovery can cause up to 40 percent of local businesses to go out of business as revenues drop while rents and loans never sleep.

The Resilient Design Performance Standard addresses this issue by working with communities to systematically identify reasonable recovery times for infrastructure that supports community functions and that can serve as a key metric of future project design and maintenance. Cost still matters. Robustness still matters. But what is new is a recognition that how long it takes to repair a system also matters. And by including recovery time based on local priorities into project design it opens up new alternative solutions that may cost much less, new alternatives that deploy alternate work-arounds that are supported by the community, and new design solutions that support local priorities based on community health and function.

The Boulder approach revealed a key question: is hardening the only solution? Do we just make every project stouter so it fails less often? Not necessarily. While hardening is one alternative solution to consider, it is by no means the only approach. To help design teams think more creatively, the Boulder Resilient Design Performance Standard includes a check list for project designers to help them identify a broader array of integrated project design solutions and workarounds that build on the attributes of socio-ecologically resilient systems. It ties together existing comprehensive plan goals, existing criticality and vulnerability assessments, economic development, watershed and ecological restoration plan goals. And it opens up cost-effective alternatives for consideration during project design that leverage other community attributes in order to get an outcome that meets broad community goals and aspirations.