Flood season is here and sure to have an impact on people and the health of the Colorado River.
River forecasters paying attention to Colorado’s banner snowpack this year are predicting runoff will fill reservoirs and provide for exciting whitewater. The weather from here on out will determine whether that snowpack runs off slow and steady or brings floods. Spells of warm weather coupled with rain can turn valued snowpack into damaging floods quickly. When floods do come, media coverage focuses on risk and loss or damage to life and property. Floodwaters can erode valuable farmland and wash away cherished homes and livelihoods. And take lives.
But there is another flood story that is not being told – floods can be a boon to habitat and river health. Many of Colorado’s rivers are blue ribbon fisheries, they support healthy populations of bald eagles, ospreys and herons that nest in riverside cottonwoods, and trophy whitetails that find refuge in river bottoms. River and floodplain forest habitat along Colorado’s rivers can benefit from flood flows, not despite them.
Floods are natural events that erode channel banks, entrain trees that stack up in logjams, and create new side channels, gravel bars and sand deposits on the floodplain as they have for millennia. While flooding may damage homes and infrastructure and affect the livelihoods of farmers and ranchers, it can also be seen as part of the natural process of maintaining a naturally functioning and healthy river system.
Healthy rivers spill out onto their floodplains, which filter sediment and pollutants and act as a sponge to recharge groundwater, supporting cold water base flows later in the summer. Water that spreads across the floodplain dissipates flood energy and makes its way downstream more slowly, reducing downstream flooding. Rivers that migrate across their floodplains create open gravel bars that are ideal for cottonwood seedlings, creating and sustaining our picturesque cottonwood forests.
If they come, this year’s floods will present an opportunity to observe the power of the natural world and the benefits of big flood events. As the floodwaters recede, check out the patterns of erosion of deposition and look for new crops of willow and cottonwoods on point bars. Explore new side channels and the spawning and rearing habitat they provide. Good habitat is created through messy and dynamic processes. But if we see the eroded banks, new channels and log jams for what they are – new habitat that is vital to river and riparian health – we can learn to manage our rivers as vibrant corridors that experience necessary change rather than static systems on our landscapes.
Protecting land from flood damages is understandable, as those damages can be unforgiving and costly. Yet protecting property from flood damage sometimes constrains processes that can benefit river health. To balance property rights and river health, we can look to voluntary programs in other states where floodplain landowners can receive compensation if they allow rivers to flood and erode their banks, sustaining key habitats. And here in Colorado, landowners are beginning to explore increased flooding on their ground by incorporating treatments that mimic beaver dams to benefit from groundwater recharge and reduce flooding downstream. With collaborative partnerships and creative approaches to managing rivers, we can secure a river stewardship legacy for Colorado that includes celebrating floods as rejuvenating ecological events.
Peter Skidmore is a program officer with the Walton Family Foundation’s healthy rivers program, focusing on the Colorado River initiative.
