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EXTENDED: BAER team speaks on impacts of the Dragon Bravo Fire

A portion of the Kaibab National Forest partially burned by the Dragon Bravo Fire.
USFS
A portion of the Kaibab National Forest partially burned by the Dragon Bravo Fire.

Last month, teams of scientists finalized their reports on how the Dragon Bravo Fire impacted the environment across its 145,000-acre burn area.

They found about 65% burned at a low severity but almost a third suffered moderate and high impacts.

KNAU’s Adrian Skabelund spoke with US Department of the Interior Burned Area Emergency Response Team leader TJ Clifford.

Below is an extended version of an interview that aired on KNAU on September 3.

This interview has been edited for length and clarity. An abridged version of this interview is also available.

ADRAIN SKABELUND: What was your reaction the first time you maybe drove through the burn scar area?

TJ CLIFFORD: My first reaction, and this is twice, on two different occasions.

In early July, when the fire was about 4,000 acres, I came in here to triage, to make sure that we did not have any potential and immediate threats to the waterline, the water system that serves the south rim and north rim.

And in that, when we flew over that, that first reaction was ‘We have a lot of structures, there's been a lot of damage to those structures.’ And overall, 106 of them: either severely damaged or lost.

So that was, that impacted, you know, that's an emotional impact when you see that kind of thing.

But then you bring it up to flying over that fire area, and this is previously a month ago, but it was also when we flew over it and drove through it.

It's the fire, the natural part of this fire, is a mosaic.

SKABELUND: Can you speak through, kind of in maybe layman's terms, what those areas look like and what that means?

CLIFFORD: For sure. Moderate and high severity. At first glance, the vegetation mortality, the trees have died, and that is consistent throughout Forest Service, Park Service lands.

But then you come down-- soil burn severity is specific to how those soils have been impacted.

So we are seeing some background repellency. It's mild.

So that water repellency is important because if we identify how repellent it is and how deep it is, it's kind of like an avalanche and a slide surface for that avalanche: if that repellent layer is at depth, everything above the repellent area goes.

So we take a look at that. In this case, it's mild and it's not that deep. So that's first look for watershed response.

The other thing that I thought was interesting on this fire, and somewhat unique is: overall there's a fairly thin ash layer. So the ash layer is not substantial.

And then two other things we noted in the moderate, we identified them as moderate so- soil burn severity, but there was no change in the soil structure, and even fine roots were intact.

So to visually talk through what that looks like, when you dig in there with your hand, you're going to find a lot of the grassroots are still there and intact. They have not been consumed.

And then the other cool thing that we noticed in almost every situation is [that] both shrubs and aspen are re-sprouting already. In some places on some hills, with the rains we've been receiving over the last week, the re-sprouts are at 18 inches high.

SKABELUND: And are those re-sprouting or re-growing in areas of high burn severity, or is that more in low to moderate?

CLIFFORD: It includes the moderate. Low, of course, yes. Low, we expect that to come back very quickly, within the first year.

Moderate, on some fires, we do not expect that to happen until about two years out. And high would be longer.

SKABELUND: You mentioned the ash layer is not substantial. I guess, what does that tell you? Why is that notable?

CLIFFORD: In this case, the story it tells us is the ground story, the grasses and the smaller shrubs were not substantial.

And when they were consumed, that was all that was on the landscape. As opposed to a substantial ash layer would mean that you had a lot of duff, or a lot of litter, organic matter that burned and caused more damage to the soil.

And one of the larger results is, when you have a thin ash layer, your impacts to water quality, even if temporary, will be less.

SKABELUND: You mentioned this kind of patchwork for the high and moderate burn severity.

What does that pattern of the burn tell you about the fire?

CLIFFORD: So this is a-- we're seeing a mosaic burn here with a mix of mostly low burn severity as a result of two things. Past fires, so fire history. And fuels management -- proactive management by the Park Service trying to manage the fuels and reduce, not the likelihood of a wildfire, but the impact from the wildfire.

And that's really important to note because one, that's proactive, but that helps us incorporate even a wildfire as a tool in the future.

SKABELUND: Is it too early for us to know kind of the implications for debris flows and runoff, um, into some of these drainages down to the Colorado due to the fire?

CLIFFORD: It is too early. We're still in the modeling phase. But I will say that USGS has a product out there already for the debris flows, so they have talked about that.

When you look at those debris flows, I think most importantly you would, you would pay attention to the likelihood, and that, for the most part, is 0 to 40%.

So yes, there is an increase of likelihood of a debris flow happening.

I think we're seeing the same thing with when you have a regular [precipitation] event and it doesn't get to that level of a debris flow. It's more of a flood.

And to talk specifically, Bright Angel, Transept, those canyons, we are seeing increases, but they're not substantial.

SKABELUND: What are the next steps for a report like this?

CLIFFORD: What we do right now is we're putting together the rationale to mitigate some of the threats to public safety. For instance, we got rockfall on the trails.

We have some areas within the North Rim development area that we need to stabilize because of hazards. A burn structure usually equates to hazardous material, and we need to help stabilize that until that hazardous material can be removed by qualified experts.

That's tough to do, so that takes time. So, our program will, will work to bridge the gap between the fire and the restoration, and that includes that developed area.

I will say that part of what the park would be looking for is specifically North Rim trails. There's rock-- so we lost vegetation holding the rocks on the hill slope. That rockfall will happen and hit the trail in multiple locations, especially in the steeper sections, much more often.

And that is a risk that the park needs to understand so that they know how to, whether or not to allow visitors to keep using the trail system.

That would be kind of a spinoff product of, uh, when we look at this, we're looking at life and property first, and natural and cultural resources second.

SKABELUND: Are there any other areas that already are top of mind in terms of, "Oh, this is an area that's going to need work and remediation?”

CLIFFORD: There are roads. Even the last few days, we've had some minor flooding on some of the roads in there, so we'll have to pay attention to that.

Clean the drainage systems associated with those roads. And then, like the campsite, campsite’s vault toilets, that kind of thing for recreation and to support the recreation in this area. We'll have to make sure those are safe. So removing hazard trees that are near those so that we can provide a safer environment for the recreationalists to come back and utilize this area.

And then last, North Rim, 106 structures either severely damaged or lost. But in that, we still have threats.

So, if you look at, like, the deluxe cabins area, those who are familiar with that, they have standing chimneys. The lodge has pillars that are quite high.

We need to take a harder look at whether or not those are going to stay or if we need to keep the public out, public and workers out, for some period of time to make that safe.

And then that will allow us to come back in there. But yeah, like I said, life and property is number one. That's our number one goal, is to find ways of minimizing the threat to people.

SKABELUND: TJ, thanks so much for giving me some of your time today.

CLIFFORD: Yeah, thank you. Very nice to meet you, and thanks for the opportunity.