CLIMATE CHANGE AND PRACTICES AT MaineDOT

It is now generally accepted that climate is changing. Regardless of the “how” and “why” of climate change, it is becoming apparent that a variety of MaineDOT practices should be reviewed for continued viability in a changing climate. The science of climate change can provide some indication of potential future changes in Maine's precipitation climate, but it is up to MaineDOT policy makers and engineers to adjust MaineDOT practices accordingly. One area of concern is the effect of climate change on MaineDOT's hydraulic structures. Anecdotally we hear that we have been experiencing 100-year events annually for the past few years. MaineDOT is working with US Geological Survey to see if in fact design events are getting bigger. Hydraulic design, and associated policies, may change as a result. An on-the-ground reality is that most transportation drainage structures and bridges are designed to last from 20 to 100 years, so in many cases the opportunity to size for long range increased flows immediate while specific environmental outcomes are still unknown. Without knowing for sure whether projections are conservative or extreme, MaineDOT needs to use the best available science in conjunction to estimate the need to change current practice in anticipation of increased duration, volume, or frequency of flows. We have opted to go forward with assessing whether our current practices and policies are adequate to respond to a range of future hydrologic changes.