The Dolores River was the first Western river I ever paddled.
It was the start of the spring melt and, relative to anything I’d ever paddled before, I remember it as a big river with big waves, silty thick waters and big sand beaches.
I didn’t realize it at the time, but that was the last time the Dolores would see regular spring runoff flows. That year, in 1984, the then-new McPhee Dam closed and has since allowed only about a third of historic flows.
Only on big snow years, when excess water is expected, does the Dolores see the high spring snowmelt flows that for millennia maintained its wild river character and habitat. Those flows allow boaters to experience the wilderness canyons from there to its confluence with the Colorado River 170 miles below.
This year was one of those big snow years. McPhee opened its gates in May and let the snowmelt run as part of a management plan negotiated to provide recreational and environmental flows on big water years.
And this year, I joined the snowmelt for a five-day trip through the Ponderosa and Slickrock Canyon stretches – 97 miles in total. We set out with clear, warm skies, a few days before the Memorial Day crowds and as flows were being ramped back down from a peak release to a minimum flow.
Though it had been decades since I’d paddled the Dolores, I had gotten to know the river pretty well through my work with the foundation and collaborations with scientists doing research on the Dolores.
The Dolores had been one of the priority tributary rivers for the foundation’s Colorado River program from about 2010 to 2020. It was one of a handful of rivers where the foundation supported watershed-scale riparian habitat restoration.
Like many rivers in the West, the Dolores had become overrun with tamarisk, an invasive shrub that is very well adapted to regulated (dammed) rivers and overgrazed floodplains. Our partners were experimenting and scaling different methods of removing tamarisk to reestablish native willow and cottonwood along the river.
The foundation believes innovative ideas and partnerships can protect water resources and watershed health in the Colorado River Basin, which provides water to nearly 40 million people in seven states. What we learn from restoration efforts on the Dolores River can also help us adapt our strategy in pursuit of a long-term vision – to ensure the American West has enough water and healthy watersheds to sustain the region's natural and working lands.
My trip down the Dolores was part of that learning journey.
The Dolores at high flow is a sporty river and took a lot of concentration. But between rapids, I was able to float and observe with curiosity the changes taking place.
We gradually descended through shifting mosaics of native riparian vegetation, from Ponderosa pine forests in the upper reaches to Juniper, box elder, willow and cottonwood. But there was no hiding that the Dolores has been fundamentally changed by decades of regulated and diminished flow and cattle grazing.
Without regular and occasionally extreme spring runoff flows, the channel shrank and narrowed. It simplified and lost diversity of habitat, while the riparian plant communities steadily shifted to pervasive stands of impenetrable and inhospitable tamarisk.
Native willow and cottonwood are flood-adapted and flood-dependent species. Without the disturbances of regular floods and with the impacts of grazing these plants cannot compete with tamarisk. McPhee has captured most of the sand and fine sediment that used to resupply the river’s beaches and provide for natural native plant recruitment.
But during my five days on the river, I also saw a river reclaiming some of what has been taken from it.
At high flows, I saw a river doing what a natural river is supposed to do – flooding the floodplains, pulling trees into the river, forming log jams, scouring pools and leaving sand on beaches and bars. It was recreating the complexity that provides for diversity of life and habitat.
I also saw increasing signs of a dynamic river as tributaries contributed sand and debris that adds complexity to habitat. And I saw the changes brought about by the active management of our partners in their efforts to reverse the balance of invasive tamarisk and native trees.
I saw miles of actively restored healthy native riparian habitat. I saw miles of native plants reclaiming their dominance through natural processes.
The core hypothesis and assumption of managing invasives with the expectation that native plants will rebound is yet to be proven or shown to be durable. We’re still learning about the impact of the innovative restoration work on the Dolores.
For instance, I saw the tempering impact of the tamarisk beetle that has been in the Dolores watershed since 2008 and can limit and reduce tamarisk’s ability to reestablish. Tamarisk will always be in the system, but maybe the native plants can compete now, though the diminished flows will continue to make this even more challenging.
I witnessed a changed river and am hopeful that it may be trending toward a new equilibrium, a novel ecosystem, where at least the riparian habitat and wildlife that depends on it now stands a chance.
