The group American Rivers is out with its 2024 list of the country’s most endangered rivers. The rivers of New Mexico top the list, followed by those in Mississippi and Tennessee.
But fourth on the list is Arizona’s Santa Cruz River. The main threat, according to the report: water scarcity.
Luke Cole, director of the Santa Cruz River Program at the Sonoran Institute, said he was pleased to see the river on the list. He spoke more about it with The Show.
Full conversation
LUKE COLE: I was delighted that they nominated us, because we nominated the river, so it didn't come as a complete surprise. We were very pleased and proud to offer up the river. But no, it wasn't a complete surprise that we had been engaged in the nomination process all along.
MARK BRODIE: So when you say that you are pleased, is that a matter of getting attention? I can't imagine you're thrilled that it's among the more endangered rivers in the country.
COLE: It cuts both ways. Honestly, so pleased, because the reason that we nominated the river is that it's very new in its recovery. You know, this is, I don't know how well the parallel works, but it's something like a toddler to a newborn. You know, this is a river that has been really battered for 100, 150 years, and only within the last 10 to 15 years has had any sort of rehabilitation. And it is because of how new and tender this recovery is that we thought that the river warranted nomination as threatened. It is just threatened by its newness.
BRODIE: Is it safe to say, though, that the Santa Cruz River is doing better now than it was maybe five or 10 years ago?
COLE: That is absolutely the case. So the river has two major flowing sections. There's one closer to the border. We call that the Nogales reach, that flows south to north, as does the stretch up here in Pima County and the city of Tucson. Both of those have had upgrades to the wastewater treatment plants that create the water that is the Santa Cruz River in anywhere between 2008 and 201, so it's really been since then that we've had clean water flowing in the river, and the river conditions on the whole, are improving year after year following those upgrades.
BRODIE: What still concerns you about it, though? What do you still worry about?
COLE: Well I mean, the fact of the matter is that at least up here in the Tucson metropolitan area, we get the majority of our water from the Colorado River, right? It comes through the CAP, and as we see the continuing declines, unfortunately, of water in the Colorado River, that just sort of means that the pot of water that's available for Tucson and for anybody who's on the distribution system of Colorado River. It's threatened.
The good news is that the city of Tucson and really all of southern Arizona, and honestly a lot of Arizona, is doing fantastic work in water conservation. So the threat is sort of the broader existential one. The comfort comes from the fact that policymakers are making really good decisions around water conservation, which gives that much more confidence around the Santa Cruz River’s continued rehabilitation.
BRODIE: It’s interesting how the future of the Santa Cruz is so closely tied to the future of another, I think endangered, threatened river in Colorado.
COLE: That's absolutely correct. And it's the source water, at least for again, for the Pima County stretch of the river, the stretch of the river down closer to the border. The majority of that water actually comes from the southern part of the watershed, much of which is in the state of Sonora, around Nogales, Sonora.
So that's a completely different system. It's within the Colorado River watershed. It's subject to a lot of the same climate change and development pressures that the rest of the Colorado River system is, but it does have something of a hydrological disconnect.
BRODIE: Oftentimes, I think, when people think about threatened or endangered rivers, they think about things that people can do to try to clean them up, or to protect them, or to make them less threatened. Is that the case here? Like, are there things that people can do to help the Santa Cruz River, given, as you've discussed, sort of its relationship and in some ways, reliance on another river?
COLE: There are, and they all really lie around water conservation and water technology measures. People have helped out tremendously over the past 30-plus years, taking Tucson here as a case study. Cumulative water use per year from the city of Tucson has not gone up since the middle of the 1980s. That's because elected officials, career officials, people who live here understand a water conservation mindset and are using less and less water per person per day. That's critically important, and as a result of that, we are continuing to see, you know, there's still enough water for the Santa Cruz River, and it's been really impressive decision making around policy that has been made at the municipal, county, state and federal levels, federal on in both sides of the border to improve the water treatment trains that ultimately create the Santa Cruz River.
So people are already doing that work. Another thing that people can do is to join this larger partnership that's been established here, a coalition of neighborhood groups, water practitioners, elected and career officials who are working to establish an urban national wildlife refuge for the entirety of the Santa Cruz River here, and that would bring, it would really leverage efforts to restore river flows and improve climate resiliency by bringing the federal government here to acquire land and to afford protections to this river that, again, is so early on in its recovery.
BRODIE: How optimistic are you that at some point in the future, the Santa Cruz River will not need to be on the most endangered or most threatened rivers list?
COLE: I am nothing but optimistic about it. I think that in reviewing the most endangered rivers listing for the Santa Cruz River, what you're going to see there is all of the good work that's happening down here in southern Arizona to protect and celebrate this river. The only threat to it really is, again, in how early on it is in its rehabilitation.
So I have absolute confidence that the work that's already happening and has been happening over the last couple of decades will continue and will bring more attention to the river, get more people celebrating the history and the vibrancy and the ecology of this river that will continue to encourage us to do the right thing, to allow this river to flow and to recover. So I think it's going to be a really short amount of time before this river would be off the list.
