We do 5, 10 and 20 year plans for infrastructure. But how long do we expect to this infrastructure to last? For example, how many roads only last 10 or 20 years? Most roads only seem to grow with time. Ancient Roman roads are the basis for many current roads. We keep adding roads – few are ever abandoned. They simply do not go away. So a 5, 10 or 20 year planning period makes little sense.
Roads are not the only limit. The WPA-era water mains are approaching 80 years old, and still providing good service, and our Clean Water Act-era sewer improvements are approaching 40. Sewer lines are similarly situated. Many water plants are over 70; we celebrate 100 years on many. Again, planning for only 20 years makes little sense in the context of the larger length of time.
More interesting, we rarely borrow money to pay for these projects for less than 20, 30 or 40 years. So our infrastructure outlives our plans and our borrowing. Often permits are less that the borrowing for infrastructure, which can cause stranded capacity in plants that may never be used. Miami-Dade County has such a situation – they are not alone.
Let’s look at this in the context of groundwater withdrawals. There are areas across the US where groundwater levels have fallen. They have fallen because of human activity to pump them for crops and water use. Colorado has a 100 year management plan in the Denver basin which is basically make the water last 100 years. Then what? Texas has shorter plans. The eastern Carolina drained parts of the Black Creek already, so this is not a theoretical western state issue only. How do we address this?
Or let’s go back to Miami-Dade County the outer banks of North Carolina, historical downtown Charleston, SC, and many other venues where sea level rise could impact water, sewer, storm water and roadway infrastructure. As we redevelop those area, should plans look at the true life of those assets (100 years) vs. the 20 year plan?
Both issues involve the sustainability of infrastructure systems, which means the ability to adapt them to changing future conditions. We have known for 10-15 years that stationarity is no longer accepted for future projections. But we need leadership to move the infrastructure planning to the future changing conditions.