In this episode, we’re talking about a creature that one doesn’t often associate with the American Southwest. We’re talking about beavers! This keystone species is every bit as industrious as you’ve heard, to the point where beavers are called ecosystem engineers.
But a quick pro tip: In order to thrive, beavers need year ’round flowing streams like this one in southwestern New Mexico.
Here to bring us the latest on our regional beaver population is Jace Lankow from the Tucson-based Watershed Management Group.
Transcript
INTRO: From Tucson, Arizona, welcome to the Water Harvesting 101 podcast. My name is Martha Retallick. I’ve been a water harvester for 20 years, and I’m looking forward to helping you get started.
Before we do that, here’s a little Tucson secret: For most of the year, we’re in drought. That’s just how life is in the desert.
But when the rains return, oh, do they ever. They often bring an unwelcome friend called flooding.
How do we reduce the risks of flooding? We do it with water harvesting.
Water harvesting encompasses three activities:
- Redirecting rainwater away from where it isn’t wanted to where it is.
- Storing rainwater for later use, for example, during a drought.
- Recycling “used” water. At my place, I don’t let laundry water go down the drain. Instead, it’s for the fruit trees.
We’ll be covering all of these topics and more, so let’s get started.
EPISODE: In this episode, I’m going to talk about a creature that one doesn’t often associate with the desert Southwest.
I’m talking about beavers, and here to tell us more about the important role that beavers play in our arid environment is Jace Lankow from Watershed Management Group. Welcome to the podcast.
Jace: Thanks so much, Martha. Great to meet you. Glad we connected at Beavers and Brews and happy to be here.
Martha: For the record, Beavers and Brews was an epic party that the Watershed Management Group just threw in honor of the beaver. It happens once a year, usually toward the end of September.
And if you want to get onto the invitation list for next year’s event, go to WatershedMG.org and subscribe to the newsletter.
Jace: Wonderful. Already looking forward to the next one.
Martha: So, at one point, our region had a lot of beavers. What happened to them?
Jace: I would like to start and just have you in your mind’s eye, imagine what you think of as a pristine river ideal.
Most often people will associate a pristine river with a single thread channel that winds like a giant S through the landscape and maybe has some trees bordering either side of it.
But other than that, it’s this water course in an otherwise arid landscape, especially here in the desert Southwest, is what we imagine. The reason that we think this is because we have to go all the way back to the 1700s if we want to see what the pre-settlement condition was like.
And by that, I’m talking about wetlands that were associated with rivers, swampy meadows. Out here in the desert Southwest, we call those cienegas. And rather than this deep channelized single stream, we’re talking about shallow anabranching, as in braided streams, all connecting of the same river course.
So, I want to preface with that because what changed in those hundreds of years what changed is some land use changes such as logging, grazing, and trapping, specifically. The trapping that I’m talking about is of the North American beaver and that was for resources such as the fur trade oil.
Or even today we are seeing an overlap with beaver looked at as this nuisance species where we overlap with their habitat and we have a misunderstanding of how they modify their habitats, aka cutting down trees, felling trees, and flooding the landscape, which are looked at as bad things when you have that human interaction.
Martha: Okay, so beavers can be both a nuisance and a help. I’ve heard that in places where the beaver dams might cause flooding, the solution is put a drain pipe in the dam.
Jace: Unfortunately, especially if there’s a dam there, putting a drain pipe… The beavers will naturally just try to plug that up as well.
So, that is the issue with culverts is going under under roadway. Beavers see that as, “Hey, here’s this dam here already with just a small hole. Let me plug that up and create my home, my pond.”
So, again, we’re talking about beaver restoration and the positive effects that they have on the landscape. Of course, it comes hand in hand with how their ecosystem coincides with where we live.
We’ll discuss a lot more about that, but I just want to preface that.
And honestly, this is more of just a reframing or maybe a philosophy or culture shift if we’re going to be able to live with this animal and reap the benefits of the positive impacts they have on the landscape for us.
Martha: Okay, so they were just about hunted to extinction in this part of the world, and they’re being reintroduced. Tell us a bit about that.
Jace: Yeah, so they were trapped to extirpation. So yeah, they were eradicated from the landscape.
In the late 90s, there was a reintroduction effort. We’re talking about the San Pedro River, in which the headwaters begin just south of the border, maybe about 10 miles or so of the international border with Mexico.
The San Pedro River runs north over 100 miles to its confluence with the Gila River eventually.
For a little reframe of where this exists, this will be east of Tucson as the river course runs. And it is quite a rural landscape as it goes through some smaller towns and a lot of grazing patchwork of public and private lands.
With that said, the San Pedro Riparian National Conservation Area – which is known as SPRINCA for the acronym – the beaver restoration or the beaver reintroduction effort was started in the late 1990s by the Arizona Game and Fish Department. It was very successful in that area.
The population of beavers got up to over 100 individuals and it was looking like a success story. Many of those beavers even moved upstream, which in this case is south into Mexico, to more stable ranchers’ reservoirs that were maintained and that had year-round water.
So they found a happy home there, and we will occasionally see them move back north into the U.S.
And of course, there are individuals along the San Pedro in the U.S., but we can discuss further on what the stability looks like in those areas and why they might not be as permanent of residents.
Martha: What’s happening to cause their populations to decline, even with the introduction?
Jace: Yeah, so there’s still that human-wildland interface.
Beavers are not protected in Arizona. They are protected in Mexico. So, this could be an opportunity to get that legislation in place.
But first, again, we need that reframe of why beavers can be a help rather than a nuisance to us for riverine management.
So, yeah, they’re still hunted. They can still be eradicated from private property because of those nuisance aspects.
And, overall, we’re in a long-term drought here.
Beavers need permanent water. And a lot of the historically perennial stretches of the San Pedro are now intermittent or even just seasonal, which can’t support this semi-aquatic animal.
Martha: It’s a little hard to be a beaver in those conditions. Now, how do beavers help an ecosystem?
Jace: So, you may have heard the term keystone species. Beavers fall into that category. They play a crucial role in keeping an ecosystem healthy.
We also call them an ecosystem engineer. They fell trees by chomping them down with their incisor teeth.
They build dams out of this wood, and they pack them with mud rocks and whatever they can get their hands on. They’re quite cute while doing this too – if you you can find a video of them creating a dam.
So, this dam slows water and impounds the water to create the beavers’ pond habitat, which they call home and build their lodges.
The secondary byproduct of that is the water being slowed helps spread the water. This helps to infiltrate water and slow sediment, prevent erosion, and, ultimately, improve water quality.
It boosts biodiversity, just by having a wetter landscape and a higher diversity of plant and animal species, thanks to the slowed water flows.
So yeah, their positive impacts abound and taking a keystone species such as the beaver away from landscape just sort of unravels the ecosystem as we’ve seen over the last couple hundred years.
Martha: That was Jace Lanko from Watershed Management Group telling us about beavers and their role in the environment.
If you’d like to learn more about beavers, Watershed Management Group is hosting a binational beaver survey on Saturday, November 15th, and on Monday, November 17th, a Beaver Believer event.
You can learn more about these events and get signed up at WatershedMG.org.
OUTRO: Thanks for listening to this episode of the Water Harvesting 101 podcast. If you’d like to learn more about water harvesting, meet my book family.
First, it’s City Nature, the book that’s guaranteed to look great on any coffee table. City Nature reveals my secrets to water harvesting through my 20-year journey of transforming my Tucson home into an urban oasis. Get the details at CityNatureBook.com.
And if you’re on the go, take water harvesting with you. Water Harvesting 101 is an audiobook and eBook combination that will teach you the nuts and bolts of water harvesting and show you how to put them to work. Available exclusively at WaterHarvesting101Book.com.