What Michigan Tells Us about the Fate of Old Water Infrastructure
Don’t just fix old dams. Decommission what doesn’t work and supplement it with green infrastructure where possible.
Last month’s dam disaster in Michigan forced thousands to evacuate their homes after heavy rains toppled the banks of two dams — a stark reminder that much of our existing infrastructure was originally built and retrofitted for needs that look very different today than they did 50 years ago.
We can’t be surprised by extreme rainfall and flooding, and we have to expect them to become even more frequent. The Michigan disaster was not a surprise, either. Michigan is the most recent cautionary tale in a growing list of destructive and costly dam failures the US has endured in recent years — and certainly not the last.
There are more than 90,000 dams in the US today. A significant portion of these dams are over 50 years old, and nearly 28% are considered high or significant hazards if they fail (according to an opinion piece by Manu Lall and Paulina Concha Larrauri in the New York Times). The US needs a plan to prevent these old, dangerous dams from becoming the next disasters.
Let’s Build a Roadmap for a Comprehensive U.S. Dam Plan
But most of the talk I hear is focused on rehabilitating dams. And while meeting current needs might mean major retrofits for some, we also must consider a comprehensive plan for decommissioning and removing dams where rehabilitation is not the safest nor the most cost effective option.
We have the opportunity to build a roadmap for that plan. It’s most likely we’d prioritize the smallest and oldest infrastructure first, which means infrastructure on the East Coast (east of the 100th meridian).
We also must consider a comprehensive plan for decommissioning and removing dams where rehabilitation is not the safest nor the most cost effective option.
— John Sabo
We can use these early projects to determine what a more comprehensive decommissioning plan would look like across the country, including how we can best weigh future utility and future return on infrastructure investment. For some dams, it will be safer and more cost-effective to remove instead of rehabilitating, especially when weighed against the indirect costs of potential future disasters.
We also need to make green infrastructure a foundational part of our overall plan for U.S. dams. With strategically placed green infrastructure, we have the opportunity to future-proof and make climate resilience central to dam policy.
Damaged dams, for instance, can be bolstered by green infrastructure. Future H2O’s work in Texas suggests that constructed wetlands of modest size can flatten the flood peak enough to give dam operators enough flexibility in release schedules, and that flexibility offers the potential for stronger integrated flood control and increased storage for supply.
Whether it’s the next Michigan disaster or an onslaught of defunct dams we’re not prepared to manage, comprehensive planning at the federal level is a must.
Japan as a Model
But how do we create a comprehensive plan when we don’t have a culture of planning and future-proofing against these kinds of disasters?
The U.S. needs an external task force that brings together all the best thinking on retrofitting, decommissioning, green infrastructure, and cost-benefit analysis.
The task force should then develop a report that includes formal guidance on which dams should be prioritized and what should be done based on a comprehensive analysis of future use and return on infrastructure investment, including what opportunities exist to integrate green infrastructure and sustainable practices.
Though a much smaller, more organized country with far fewer dams to evaluate, Japan is a proof point for nationwide foresight in a country whose risks of not planning are extremely high. And with thousands more dams in disrepair, risks in the U.S. are even higher.
— John Sabo
For instance, as Japan faces increasingly larger typhoons, that country is thinking nationwide about how to retrofit all their structures — and in environmentally friendly ways, including operational strategies that are good for downstream ecosystems.
Though a much smaller, more organized country with far fewer dams to evaluate, Japan is a proof point for nationwide foresight in a country whose risks of not planning are extremely high.
And with thousands more dams in disrepair, risks in the U.S. are even higher.
It’s unfortunate that it took a disaster to refocus attention on the perilous state of many U.S. dams. We need to keep a laser focus on this issue, especially where it intersects with environmental justice.
The U.S. must develop a comprehensive plan for its dams. And that plan must prioritize not just rehabilitation, but decommissioning and the role of green infrastructure as part of how we create resilience against the ever-increasing impacts of climate change.