For the first time in a long while, we got some rain on Thursday. The drought is now on month three in our region, and a huge fire in the Great Barrington, Massachusetts, continues to burn the forest. It seemed like a good time to check in with an expert for some perspective on what's going on.
NEPM’s Carrie Healy asked David Boutt, a UMass Amherst hydrogeologist, if this rain could impact the firefighting efforts in the Berkshires.
David Boutt, UMass Amherst: The rainfall that we're seeing [this week] is going to really help abate some of those conditions, because the soil has been so dry. We have a lot of dry leaf litter and other dry detritus on the ground from the growing season. And I think this particular rainfall will be most helpful, actually, in having a little bit of moisture that will reduce the fire risk. So, I think that's what people are hopeful for in terms of reducing those impacts to the wildfire.
Carrie Healy, NEPM: So, this clearly is not enough water to actually quell the fire.
Right. Yeah. But [it will help] in terms of concerns about having additional ... red flag warnings for fire conditions, into the future.
So how much rain are we actually down at this point? What are those inches looking like?
It depends a little bit on where. In the Connecticut River Valley, we're looking at something like 6 to 7 inches of precipitation deficit. There're some records out there that suggest that this is one of the driest three-month consecutive periods that we've had in our historical instrumental records. Hydrologists refer to this as a deficit of soil moisture. [That means that] before the water can percolate through the soil to make it into the groundwater and into streams, it's got to fill up this soil moisture deficit first.
We don't usually have that deficit to contend with because there's always a little bit of moisture in there, right?
Yeah. And typically, as soils dry out, they become less able to absorb that moisture, depending on how much clay content they have. But generally speaking, these are probably some of the driest soils we've had in probably 100 years, maybe back to the 1960s, which was the largest drought that we have on record.
I'm going to ask you about that in a little bit. We're standing in the rain. I'm going to open my umbrella. It's starting to come down a little bit more. We're supposed to get about an inch of rain in this entire storm. Here in western Mass., is this really going to make a difference?
I think in terms of ... new fire risk, it will. In terms of replenishing the soil moisture deficit, having water that infiltrates into the ground, this is a start. But we need many events like this into the future.
Typically, this part of the year in New England is when it starts to get wetter, because during the growing season, there's a lot of water use by plants and evaporation. And so we typically start to recover those conditions in what we refer to as the shoulder seasons when we're able to move water through the soils, into the ground that replenishes the aquifers, that replenishes the stream flows, leading to higher levels in the spring.
And we're going to need not only events like the one we're seeing today, but above-normal precipitation to make up that significant deficit.
Historically, there was a humongous drought in western Mass., in 1962 for what, five years?
Yeah, about five years. We consider that to be the drought of record here. It was a multiyear drought, where — at the peak — [we had] two consecutive years of precipitation amounts of like 25 or 26 inches. We normally get 45 to 50 inches of precipitation. So, about a 50% reduction in precipitation.
That led to pretty significant impacts in terms of shallow wells drying up. And it actually initiated the groundwater monitoring program that we have now, that we use. Most of the wells that we use to track changes in how much water is in the ground, they started back in the mid-60s, because people didn't have that information and were concerned about what was happening.
Am I just hyper focused on the weather? Have you heard from people that this lack of water is concerning?
Yeah, well, I think about it a lot, of course. But I probably talk to people in the media almost daily for the last 10 days or something like that.
I think one of the biggest things that's on people's minds are the fires, right? And typically, when we have a dry period or a drought during the non-growing season, we don't talk about it a lot. The 2016 drought, the 2020 drought, the ‘22 drought have all been during the growing season where [we saw] pretty significant impacts to agriculture. During the kind of the shoulder seasons, we don't talk about it a lot.
So this is the first time in my 20-plus years here at UMass, talking about drought not during the growing season. So yeah, a lot of people are talking about how they haven't really experienced a set of weather patterns like this.
