- [Man] Certainly it looks like camper to me.

It looks like the top of a camper.

- [Woman] Gosh, that's second one that we've seen.

- [Maiya May] In May of 2020, as if the global pandemic wasn't enough, a dam above Edenville, Michigan failed causing a catastrophic 500 year flood.

Experts say we're likely to see even more scenes like this as precipitation increases and gets more erratic.

In fact, the U.S. just had the wettest decade on record with the Great Lakes Region experiencing one of the largest increases in precipitation.

And here's the problem, much of our infrastructure like dams and levees, things we rely on for safety in our everyday life, well, it was designed to withstand a much different climate than we live in today.

And when one dam fails, the next dam fails.

Things can get crazy quickly.

- [Dan Dice] Oh man.

- On this Earth Day episode we're going to talk about the awesome power of water.

And I definitely recommend watching to the end for some crucial tips on surviving the flood.

(dramatic music) The Michigan floods are a worst case scenario, but it's one that serves as a warning for homeowners and renters, even those who don't live in an officially designated flood plain, because rainfall and dam safety can change far faster than policy.

That was true for Dan Dice, who lives in Sanford, and renovated his home near the Sanford dam.

- We were in the house for seven years.

I worked on it for a year before we could even move in.

We completely gutted it.

New plumbing, new fuse panel, all new electrical, drywall.

I put a lot of sweat and tears into this place.

- [Maiya May] Then on May 17th, 2020, a spring rain storm hit Mid-Michigan.

Fueled by tropical storm Arthur off the mid Atlantic coast, it brought seven inches of rain over the course of a few days.

Upstream of Dan's house, three reservoirs on the Tittabawassee river filled to the brink.

The dams creating these reservoirs have held billions of gallons of water above riverside communities for nearly a century.

But by May 19th, they were pushed to the brink.

- Edenville dam, Wixom Lake filled up really, really fast, and I don't know why, but they didn't, they didn't drain the lakes.

- [Maiya May] Older dams can't always drain the lakes they hold fast enough to prevent dangerously high water levels.

That means an earthen dam, which is made up of compacted earth, can become completely saturated, weakening the structure overall.

And if levels get so high that water flows over the top of the dam.

- [Man] There it goes.

- [Maiya May] It's extremely likely to fail.

You can see in this video that both factors were likely at play when the Edenville dam failed.

(tinkling music) The pulse of water created a flash flood that raced downstream into Sanford Lake, a half mile upstream of Dan's house.

Then just before dark the second dam failed.

Sending what officials called a 500 year flood to the communities below.

We're just North of Sanford Lake.

All kinds of stuff floating by.

(grunts) Yeah, it gets deep quick over here.

I just gotta see my house.

(Dan grunting) (water splashing) I thought: I can fix it, I can fix it, I can fix it, I fixed it this much, I can fix it.

It was worse than I thought it was going to be.

I didn't think it was going to get that high.

The next day when we came back, it was, it was off the foundation and the foundation was wrecked.

- [Maiya May] In all, more than 2,500 homes and businesses were lost in small towns along the river corridor, where many people didn't have, or couldn't get, flood insurance.

To find out how something like this can happen, and who else might be at risk, we talked to hydrologist, Drew Gronewald, who explained how the age of dams played into this tragedy.

- So what we have here is the confluence of two problems.

One, we're getting near the end of the life of a dam, and at the same time, there was an unusual rain event with regards to the time period over which dams like this were designed.

There are tens of thousands of dams around this country that were all built in the early to mid part of the 20th century.

When these dams were designed, typically, they look at historical precipitation records, and make a determination of what, within the historical record, constitutes an extreme rainfall event, and then they make a design consideration.

The climate has changed and the frequency and the occurrence of heavy rainfall events has changed.

- Now, let's look at the hydrologic cycle to understand how climate change can increase rainfall in places like Michigan.

We'll start when the sun heats lakes and oceans causing water to evaporate.

Water vapor, which is water in the form of gas, then rises into higher levels of the atmosphere where the temperature is lower.

As water vapor cools, it condenses, and clouds form.

Wind currents then move clouds around, they collide, grow, and when rising air can no longer support that water, it falls to the ground as rain, hail, sleet, or snow.

That's all very normal and allows for life on earth to exist as we know it, but as the Earth's temperature rises, the opportunity for air to hold more moisture increases as well.

That means there's a greater potential for more heavy rain events in the future.

And all that rain can flow into rivers and fill reservoirs that weren't designed to hold that much water.

And if dams weren't designed to allow enough water to flow downstream, they can fail.

- There are tens of thousands of dams in a similar state that need some type of repair or replacement.

- [Maiya May] But even without dam failure, increased precipitation can be a real problem.

A recent study found that a third of all flood damage over the last three decades was due to increased precipitation.

This amounts to $2.5 billion per year in increased annual costs.

Kristen Smith, a researcher at Headwaters Economics, has been thinking a lot about this.

Hi Kristen.

So, we've been talking mostly about Michigan, but how big is this problem and how have we addressed it in the past?

- So in the United States, 41 million Americans are at risk of flooding.

They live in homes that are in the flood plain.

And so my passion is really working with rural communities that often don't have the resources and helping them think about how they can be safer in the longterm.

You know, historically in the U.S. the way we've dealt with flooding is to control it.

There's been so much engineering of rivers to channelize them, which of course just creates bigger issues downstream.

- Right, so we've created dams and levees, and flood walls, but damage from flooding is still on the rise.

So what else can we do?

- So increasingly we're thinking about, instead of trying to control flooding, how can we manage risk?

And how can we make people safer?

And so you've seen people really focusing on things like buyouts, elevating structures.

There's been a huge shift to thinking about land use regulations, and helping communities at the local level think about where they want to develop, and maybe where they should not develop.

And there's also been an emphasis increasingly on green infrastructure.

So those are things like wetlands restorations and floodplain protections.

- [Maiya May] In Portland, Oregon, a neighborhood and a major commercial street near Johnson Creek flooded frequently since the area was developed.

So the city used federal and local funds to buy properties from willing sellers.

Many of these flood damage homes would have been difficult to sell on the open market, but after 15 years, the buyout was complete, and the city began turning the neighborhoods back into a natural area that could hold large amounts of flood water.

Pools, big turns in the creek and wetland vegetation surrounding it gave floodwaters somewhere to go, and in the two major high water events since the project was completed, the commercial area and major thoroughfare didn't flood.

Not only that, but water quality and wildlife habitat were improved.

Done right, this kind of project can increase community equity and equality, but it often takes governmental and nonprofit support.

And it's worth doing right because the impacts of floods can exacerbate existing racial and social inequality.

- Flooding impacts people disproportionately.

And that's because of how we've settled this country and who lives where, and who's exposed to risk, and who's not.

Also who has access to flood insurance and who can't afford it.

Who has the ability to adapt and flood proof their house and who simply can't.

This is a problem that is a watershed scale.

And we need to come together as a country to figure out a plan for how we're going to adapt to climate change.

- Projects like the Johnson Creek Restoration can reduce the surge of floodwaters filling reservoirs and reduce the strain on aging dams, but they won't stop every flood.

So, here are some steps you can take to make your home safer.

First, find out if you live in an area at risk of flooding.

If you do, it's important to elevate and anchor your critical utilities like electrical panels, propane tanks, and HVAC systems, and store valuables and higher up spots.

Clear your gutters and drains, and consider installing a sump pump.

Pay attention to what your insurance covers before it's too late.

Of course, evacuate when you're told, and avoid wading and swimming in flooded creeks and rivers.

People die every year in flood waters, so keep yourself and your family safe and out of the water.