Debris litters the banks of the North Platte River. Logs and small trees are stacked at the top of islands. Branches are strewn about the banks.
Much of the aftermath of a flood can seem like a real mess if not pure devastation. But the benefits of a flood cannot be discounted.
In fact, there are many positive things about flooding. While it may not seem like it as you slowly dry out your basement, an unenviable task for sure, consider the bigger picture for a moment.
Rivers and riparian areas are made to withstand occasional floods. In fact, they prefer a good flushing every now and then.
Just like the forests evolved with occasional fires to help regenerate, the rivers need occasional floods to remain healthy.
Paul Dey, aquatic habitat program manager for the Wyoming Game and Fish, says we can often get wrapped up in the destruction and forget about the bigger picture n in essence, floods can be a good thing, too.
He says to think of rivers as a sum of water, sediment and wood.
As it spreads out, it loses some power, slowing down over a larger area, allowing the flood plain to do its job.
The problem we get into is when humans divert water into a small area.
“What we always tend to do is channelize streams,” he says. “It causes more damage, usually somewhere downstream where it goes through a narrow point and all that energy gets focused on human structures, and then it becomes a catastrophe.”
Once it has jumped the bank, flood water may move into riparian areas, recharging habitat that may not have seen water for years.
“Typically what happens is that water is sort of banked there and released over time,” he says.
In the process, it renews nutrients in the soil, depositing new ones, moving around old ones and generally shaking up the whole area with a little bit of oxygen and room to breathe. Seedlings are deposited and given bare ground to grow in.
Side channels are flooded, giving small fish a place to grow and frogs and toads happy homes.
“It’s something that is hard for us humans to get a wrap on. We tend to think about what happens every year, but some critters are only able to make hay when the sun shines every few years,” Dey says. “It’s harder to visualize and see that that sort of scenario is needed.”
Woody debris is sent down the river, creating new habitat and disintegrating into nutrients for aquatic life.
Bars of sediment are stirred up, sometimes moving further downstream. In some cases, they remain in the exact same place, with the exact same shape, but have been replaced with entirely new gravel.
Rivers naturally design themselves to withstand floods. They become efficient, able to deflect the water’s blows with little to no change. Some are so balanced they appear exactly the same, even after a major flood, says Dey.
Dey says this also helps stave off invasive species.
When conditions stabilize, meaning when a dam is put in or floods aren’t allowed to run their course, vegetations communities can shift entirely, often favoring non-native species such as Russian Olive Trees.
But if nature is allowed to run its course, it can often self police those species.
“A wild torrent can once in awhile help alleviate or help decrease some of those non-native trees,” Dey says. “Often the roots aren’t adapted to hold on in the face of that sort of torrent.”
But “torrent” is in the eye of the beholder, as is the term “flood.”
“The North Platte River in its ‘pre-development’ days, used to ‘flood’ almost every spring, and then go nearly dry later in the year,” says Matt Hoobler, North Platte River Coordinator for the Wyoming State Engineer’s Office. “A lot of headwater rivers used to do this, but the North Platte especially.”
He says this frequency is due in part to topography, geology and the water supply in the basin.
Hoobler uses the word flood in quotation marks because the definition has changed over time.
“So often when society thinks of flooding, we think of it in terms of having water where we don’t want it,” he says. “However, before the river bottoms were settled and the high flow and spring runoff events were controlled and captured, the flows of the North Platte River during the spring runoff weren’t necessarily considered floods.”
Now, floods are measured differently.
According to water data from the U.S. Geological Survey, the North Platte River was almost three feet over the National Weather Service flood stage this month. Similar floods happened in the 1980s with water coming down in torrents in 1983, 1984 and 1986. Prior to that, records indicate one other flood in 1957, with waters topping out just over the nine foot flood stage.
“Today we are used to a river channel and the water staying in it,” he says. “When it doesn’t, we call it a flood.”