Austin Amestoy: Welcome to The Big Why, a series from Montana Public Radio where we find out what we can discover together. I'm your host, Austin Amestoy. This is a show about listener-powered reporting. We'll answer questions, big or small, about anything under the Big Sky. By Montanans, for Montana, this is The Big Why.
Today, we’re talking about climate change and groundwater. Reporter Aaron Bolton is here to explain. What are we getting into specifically?
Aaron Bolton: We received a question from Constanza Von Der Pahlen of Polson. She works on land and water conservation in the Flathead Valley. She’s been thinking about whether a faster melting snowpack due to climate change will impact our groundwater supplies. Think wells for homes and farm irrigation.
Constanza Von Der Pahlen: I was just kind of curious how is this going to change, if it will. I don’t know.
Austin Amestoy: How much faster is our snowpack melting?
Aaron Bolton: Experts say it’s peeling off two to three weeks sooner on average. The snow will only melt faster as the climate warms.
Austin Amestoy: I assume her big concern is that this could mean less water in the future?
Aaron Bolton: Exactly. Von Der Pahlen got interested in this issue because of a recent study that showed ground and surface water systems in the east Flathead Valley are interconnected.
Like most Montanans, you probably know the correlation between the snowpack and how much water is flowing in our rivers and lakes. But snowmelt also recharges these underground water systems, and flows back into our rivers and streams, keeping them running even after the snow melts.
Ali Gebril is a hydrogeologist with the Montana Bureau of Mines and Geology. He worked on that study Von Der Pahlen was talking about. He says they wanted to understand this connection because of all the development happening in the area.
Ali Gebril: There was a concern that if the increased demand on groundwater pumping will affect the surface water, will affect those small lakes, stream, creeks and the river.
Austin Amestoy: Ok, so the worry was that too many people pumping water out of their wells or for irrigation would reduce flows in rivers and streams?
Aaron Bolton: Yea, but Gebril’s study only established the connection between the ground and surface water systems. He didn’t look at whether people were taking too much water.
But the reason this is important for our question is when the snowpack melts faster and we see more rain during the winter because of climate change, these groundwater systems — or aquifers — fill up faster.
Once they’re full, all that extra water that would normally trickle through the system all summer flows downstream and is gone. That’s a big deal for farmers.
Ali Gebril: Then that water will flow quickly, and that may affect, to some degree, the agriculture, the growth season.
Austin Amestoy: But wouldn’t those aquifers hold onto that water? Are they not enough to sustain homes and farmers that rely on them?
Aaron Bolton: Every aquifer behaves differently based on the rock and soil types that surround them. Some do hold onto water longer than others.
In the past, these aquifers would fill up in the spring, but because the snowpack melted much slower, they would fill up several times throughout the growing season. The risk now is they are getting fewer of those refills because of how fast our snow is melting.
formations are found at various depths below the land surface, sometimes hundreds or even thousands of feet.
Austin Amestoy: Is there anything that can be done about this?
Aaron Bolton: That’s one of the biggest questions right now. Researchers like Gebril are looking into this idea of artificial groundwater recharge.
Ali Gebril: If we do an artificial recharge to the aquifer — that means if we have surface water available early, use that surface water to inject it, or recharge the groundwater and aquifer so that we can rely on it later in the summer.
Aaron Bolton: Gebril says there’s a lot more study needed before we’ll see projects like these.
Ali Gebril: If we want to use the groundwater as a storage facility for us, where to put that storage, where to do that injection, for how much, for where and for how long.
Aaron Bolton: He says these projects would have to strike a delicate balance between storing extra water and maintaining stream flows for fish and aquatic species.
Austin Amestoy: So this is a way off for Montana. Are other places in the country doing this?
Aaron Bolton: States like Texas are already experimenting with this idea. Kelsey Jencso, Montana’s state climatologist, says places like Texas rely on a massive aquifer that spans multiple states. There’s a lot of potential for water storage.
In Montana, our aquifers tend to be confined to our valley bottoms in western Montana, and so our potential for storage is much more limited.
Aaron Bolton: He says producers in Montana are thinking about ways they maintain these groundwater systems by changing their irrigation practices.
Kelsey Jencso: If our snowmelt is occurring earlier, that’s more water that’s running off as either surface runoff or as streamflow out of our river systems. And so, they might open their headgates earlier and allow water to flow into their fields much earlier than they historically used to. They’re building up that moisture reservoir from the crop's perspective, but it’s also banking that runoff back into the landscape earlier in the season.
Austin Amestoy: Really interesting stuff. Getting back to our listener. What does she make of all this?
Aaron Bolton: It scares Von Der Pahlen that as we see the snowpack melt faster, our water systems likely can’t capture all that water at once and we could face more drought and water shortages as a result. That’s even more concerning as people move here and pump more water out of the ground.
Pahlen has ideas of her own on how we could mitigate that problem.
Constanza Von Der Pahlen: When we weren’t thinking this was such a pressing matter, maybe 15 years ago, I was thinking of wetlands as holding — basically enhancing or creating wetlands in the upstreams as ways to hold that water which then could recharge, naturally, our aquifers.
Austin Amestoy: So she’s already been thinking about ways to capture more water in the spring, but I'm curious what she thinks about the idea of pumping water into aquifers.
Aaron Bolton: She says it’s an interesting idea, but she’s leery of artificially manipulating natural systems.
Constanza Von Der Pahlen: It’s a very difficult question because when we artificially do something, we usually find that we don’t get it all perfect and right and so then we have to go and fix something, and it doesn't work quite as well. But on the other hand, if you’re facing the issue of ground water depletion, lack of water for irrigation of our farms, all of that, it puts us in an emergency mode to come up with quick solutions.
Aaron Bolton: Ultimately, she’s happy people are starting to think of possible solutions.
Austin Amestoy: Thanks for digging into this very interesting question about the future of groundwater in our state.
Aaron Bolton: No problem.
Austin Amestoy: Now we want to know what makes you curious about Montana. Submit your questions below, or leave a message at 406-640-8933. Let's see what we can discover together!
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