Richard Lunt remembers when the Gila River and the washes nearby were filled with Black Willows and Cottonwoods, cattle ate their fill of the vegetation and ranchers pitched in to take care of the occasional sandbar.
Thanks to regulations and non-native, invasive plants with names like Kochia, Russian Knapweed, Russian Thistle and salt cedar, the Gila River looks much, much different today.
The river has become so overgrown, Lunt worries every time Duncan gets more than a sprinkle of rain.
That’s why Lunt, the Greenlee County District 3 Supervisor, was excited when the Natural Resources Conservation Service recently agreed to fund an 18-month study of the storm flows under the railroad tracks along U.S. 70, in particular those in the Railroad Wash and Rainfill Wash along U.S. 70 south of Duncan.
During a recent tour of the area, Lunt drove to both washes pointing out the issues there and other areas around Duncan.
Pointing at the Duncan-Gila River Bridge, Lunt pointed out all of the Kochia, salt cedar and sediment underneath.
“When it floods, all of this will slow the water, push it out and spread it,” Lunt said. “It will push against the levies and eventually it will either go over the levies or the levies will give.”
There are box culverts just off Highway 70 in the Railroad and Rainfill washes, but they are so filled with sediment and vegetation, the water spills over the highway and is funneled north towards homes, Lunt said. The railroad tracks simply act as a channel.
Lunt estimated the box culverts are supposed to be eight feet deep, but in some places there was a foot or less of space for water to run. Kochia can easily grow to over 7 feet tall.
A few years back, the Arizona Eastern Railroad cleaned Rainfill Wash from the highway to the river, but the invasive species just came back, Lunt said.
There are other problems that contribute to flooding, Lunt said. There’s the soil itself and aging equipment in nearby fields, he said.
“The tanks used to catch a lot of the sediment and then they had pipes where the water would come out and not form such a big head,” Lunt said. “Well, now those are all full of sediment or have been breached and so the water comes in a lot bigger head, a lot bigger volume.”
Then, when the water hits the clay-filled soil, “it just runs off it like a tin roof,” Lunt said.
Lunt has high hopes the study will result in a “comprehensive plan of attack.
“We hope we get some more conservation grant money and we’re talking about millions,” Lunt said. “The fixes aren’t going to be cheap...but first let’s find out what the problems are, what some options are and then let’s work from there. That’s our philosophy.”
“Hopefully this study will give us some causes, which some of them are very obvious, and hopefully we’ll be able to come up with solutions that working together we’ll be able to mitigate the problems,” Lunt said. “There’s no such thing as eliminating it all together, there’s not enough money in Fort Knox to do that, but we can mitigate it.”
Although the area hasn’t seen a lot of rain recently, Lunt said it’s just a matter of time.
“It’s going to flood. It’s not if, it’s when and how bad and where is the water going to go? It doesn’t take much water,” Lunt said.
Melanie Tluczek, director of the Gila Watershed Partnership, said her group would like to spend more time in Greenlee County attacking invasive species in the Gila and San Francisco rivers, but they are focusing on the Gila River in Graham County as a result of a 2014 study. That studied showed how important it was to focus on ridding the area of tamarisk and salt cedar because of the risk they pose to the Willow Flycatcher, an endangered bird. The study indicated the group would likely be most successful in restoring the area between Pima and Fort Thomas.