Army Corps of Engineers Takes on Alaska’s Escalating Environmental Crisis

Terry Gerton Mike, let’s begin with you. We’re discussing glacial flooding in Alaska. That doesn’t sound like a typical Army Corps of Engineers project to me, but what’s shifted in Alaska that has made this specific issue something the federal government and the Army Corps of Engineers felt they needed to step in and tackle?

Mike Records Yeah, Terry, this is a truly fascinating, demanding, and intricate problem that is precisely the kind of thing the Army Corps is uniquely equipped to jump in and handle. And I’ll just start by outlining the core issue. So these are glacial lake outburst floods, which we shorten to GLOF. And essentially what’s happening is the Mendenhall Glacier is transforming, and it’s been transforming since the end of the Little Ice Age. It’s been thinning and it has also been retreating. And as it’s been retreating, people have been building in areas it once covered. And I like to use an analogy: a glacier is a river. It’s a river of ice, and much like a river or a tree, it has branches. And as the glacier changes, these branches also change—these offshoots of ice that feed into the main trunk of the glacier. And so what we have here is one of these tributary glaciers has actually retreated out of the valley it once occupied and it’s left behind this over-deepened basin that is now dammed by the main trunk of the Mendenhall Glacier. And that over-deepened basin fills with water and when it fills up completely, it then suddenly releases and produces a dramatic flood that looks a lot like a flash flood or a dam-break flood in terms of its pattern. It’s really sudden, rises really fast and recedes really fast. And it’s changing every year too because of the ongoing changes of the Mendenhall Glacier. And so just to put it in perspective, it’s only developed in the last 15 years. It’s gotten way more severe in the last few years. And we really, as an agency and with our partner agencies and the truly unique skill set that we have in our centers of excellence and our ability to respond to emergencies—it’s a project that we’re really perfectly suited for addressing in coordination with our sponsors and the other agencies here.

Terry Gerton Daryl, Mike just mentioned that the glacier’s been changing since the [Little] Ice Age, although a little bit more dramatically recently. What is it about the current conditions today that make this kind of flooding even more dangerous than it’s been in the past?

Daryl Downing Well, yeah, thanks, Terry. So over the last few years, the water seems to be flowing out a lot faster and there’s a lot more volume that’s coming out of the glacier, which is flowing down the river and spilling over its banks. So under the Corps of Engineers Public Law 84-99 program, we’re authorized to help prepare for, respond to, and recover from specifically flood response or flooding issues that are impacting communities. So what we’ve been doing the last couple of years is helping the City and Borough of Juneau prepare their flood response activities by providing a lot of flood-fighting materials. For example, temporary flood barriers, sandbags, super sacks, pumps. Over the course of the last year, the City and Borough of Juneau have been ramping up efforts to protect a little bit more of the river upstream and downstream of key critical infrastructure and private properties. This year, the Corps was requested and is now carrying out the construction of these temporary flood barriers to help reduce these flooding impacts that have been getting worse over the last several years.

Terry Gerton Mike, Daryl is talking there about immediate flood response barriers and boundaries. When you think about the medium and long-term solutions to this, what do you see from a hydrological perspective?

Mike Records Yeah, I think it’s really important to highlight that what makes this situation kind of unique is, although flooding occurs all around our nation and the world, this sudden onset is unique here—sudden, severe, increasing onset. And that’s why it is important to have both this short-term response and moving into more medium-term and investigating long-term responses. But so what we look at here for looking at the long term is, we’re looking at other glacial lake outburst flood systems in the region. And there are a couple other of these basins that have been having these outburst floods for decades. And so we see those as a possible comparison to this newer system. And what those systems show is that there’s a lot of variability in the magnitude of the flooding. And so what we’re trying to do when we look at medium or long-term solutions is take that variability in flooding that we see in these comparable glacial lake outburst systems and use that variability and magnitude of flooding to prepare for a medium-term solution that could be implemented before the 2027 season, and then potentially looking at a longer-term solution that could be implemented over a longer period of years just because of the reality of constructing a large project like that.

Terry Gerton Mike Records is a hydraulic engineer with the U.S. Army Corps of Engineers in the Alaska District. Daryl Downing is the Mendenhall Project Manager with the U.S. Army Corps of Engineers from the Seattle District. Daryl, let me come back to you. This glacier is in remote, difficult terrain. You’re up in Alaska. What are the biggest operational constraints you’re dealing with as you’re trying to provide both short and medium/long-term solutions here.

Daryl Downing So one of the biggest challenges that we’re facing is logistics, because currently the area that we are working in, all materials have to be either flown in or barged in. There’s no central roadway that connects us to the continental United States, so there’s a lot of additional planning requirements for both the Corps and the City and Borough of Juneau to identify these materials that will be needed for implementation. Another factor that on-the-ground teams are dealing with is we’re working in people’s backyards. So this is something that is very disruptive to them. So we’re doing our best to construct something in somebody’s backyard with heavy equipment, lots of materials, and we’re doing our very best not to disrupt their lives any more than we have to because it’s only going to be more and more stressful as the annual flood comes to pass. So, again, we do have people out there talking directly to landowners, to business owners, to make sure that they understand the importance of the work we’re doing. And then coordinating with the City and Borough of Juneau to make sure that they are taking a holistic approach to what we are supplementing all their efforts with.

Mike Records Thanks, Terry. And I’ll also just add, even from a science perspective, the logistics are really challenging. Like you referenced, it’s in Alaska. It’s in the mountains of Alaska. It’s on a glacier in Alaska, and so a lot of the traditional techniques that scientists use for understanding and monitoring flood problems are particularly tricky here. To get up to this glacial outburst basin, you need a helicopter flight to get up there. The weather is really severe. It’s really challenging using traditional monitoring equipment there.

Here is the paraphrased version of the article in HTML format:

Monitoring equipment often fails under harsh weather conditions. Glaciers are highly active and constantly shifting. Each year, icebergs that break away from the glacier and fall into the basin end up destroying the equipment. This adds another layer of complexity to the challenge of measuring and studying how this system might change over time, especially in such a remote, mountainous, and glaciated environment.

Terry Gerton: Mike, from a science and engineering standpoint, you’ve touched on the scientific hurdles—but what lessons have you taken from this project? We’re discussing Alaskan glaciers here, but could the flood control strategies you’re developing apply elsewhere—say, to inland flooding or coastal storm surges from hurricanes?

Mike Records: Definitely, Terry. One key takeaway for me is the value of collaboration among federal and state partners. We work daily with the U.S. Geological Survey, the National Weather Service, the University of Alaska, our local sponsors—the City and Borough of Juneau—and the Tlingit and Haida tribal entity. This partnership blends scientific insight with operational emergency preparedness, and it’s been essential for pooling expertise to achieve the best possible outcomes.

Terry Gerton: Daryl, would you like to add anything?

Daryl Downing: Yes—I’d like to emphasize the planning support we’ve received from the U.S. Forest Service. As new technical data comes in, our emergency management team is ready to act quickly to reduce flood risks. Forest Service colleagues have been vital in helping us fine-tune where we place protective barriers. These long-standing partnerships have enabled the Corps to respond rapidly and safeguard the community as effectively as possible.

Terry Gerton: Daryl, let’s close with you. You mentioned working in people’s backyards and engaging with local businesses and residents. From the community’s point of view, what do they expect from the Corps of Engineers, and how will they judge whether your efforts have succeeded?

Daryl Downing: I can’t speak for everyone, but I can share feedback from landowners we’ve interacted with. Overall, the response has been very positive—they’re deeply grateful. Some even bring coffee and cookies to our construction crews and quality control staff. That said, we’ve also faced challenges since we’re operating on private property. We’re doing our best to adapt our construction approach to respect how people live and work every day. Mike, any final thoughts?

Mike Records: Absolutely. I think what people here truly value is clear communication—understanding what we’re doing and why. An interview like this is a great way to keep the communities we serve informed.

Terry Gerton: I’ve been speaking with Mike Reckertz, a hydraulic engineer with the U.S. Army Corps of Engineers, Alaska District, and Daryl Downing, the Mendenhall Project Manager with the Corps’ Seattle District. Thank you both for joining me today—and for the important work you’re doing up there.