The bad news is that the massive flooding on July 4 of the Guadalupe River did a lot of environmental damage to the river and its immediate surrounding area, the riparian area. The good news is that this was still a fairly normal event in terms of the river’s natural cycle, and it should recover just fine in the next few years.
Anna Neale and Lois Fields walked slowly through Flatrock Park, tossing handfuls of seed on the ground along the Guadalupe River.
At their feet, the flood-ravaged soil was mostly bare. Above their heads, there was little evidence of the thick canopy of trees that guarded the river’s banks just a few months ago.
Neale paused to examine a small mountain laurel that was determinedly rising from the ground.
“He’s beat up, but he’s trying to survive,” Neale said. “This is nature doing nature.”
Before July 4, when the Guadalupe River turned into a raging, deadly torrent, this section of the riverbank was shaded by trees, with so much dense vegetation that you couldn’t leave the paved walking path, Neale said.
The flood was catastrophic to Kerr County’s human population — killing 119 people and sweeping away homes, RVs, cars and anything else in its path — but it was also devastating to the environment.
The floodwaters damaged or destroyed thousands of trees and wiped away acres of vegetation, altering the river and its surrounding ecosystems. An analysis found that more than half the vegetation along the river’s floodway was lost, based on aerial images from before and after the flood. Those scars are easily visible along the Guadalupe. In some areas, trees are bent at 45-degree angles. In others, nothing is left behind but stumps and bare ground. The river banks were scoured clean in some spots, while mounds of gravel and other debris were deposited elsewhere.
It’s also not yet fully clear how much of an effect the flooding had on fish, mussels and other creatures that live in and around the river.
But the river — and the wildlife that depends on it — will recover, experts said, given time, patience and intentional restoration efforts.
Floods “are part of the natural climate, part of the natural hydrology,” said Steve Nelle, a retired natural resource specialist and wildlife biologist with the federal Natural Resources Conservation Service.
“It won’t look exactly like it did before; it’s going to look a little different,” he told Kerr County landowners at a recent recovery workshop. “But this river will heal.”
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The riparian area refers to land along a stream or lake, where the water and land meet. It’s a key area for providing wildlife habitat and for maintaining water quality by catching sediment and creating a buffer between the land and water to filter pollutants from runoff.
The river’s riparian area helps stabilize the banks and channels, and during a flood, it can help dissipate energy, slowing the water flow down, Nelle said. It also holds water in the ground — acting as a “riparian sponge,” he said, which is helpful both for temporary flood retention in less-severe flooding and for holding water in the ground during dry times.
A functioning riparian area with vegetation, including groundcover and intermediate layers, can help slow floodwaters, Meitzen said. When those lower levels are removed, leaving only the tree canopy above — as is often seen in the Hill Country — those benefits are reduced. The same goes for other clearing and building along the riparian area.
“The less the amount of developed floodplain, the more natural flood mitigation the riparian area can provide,” she said.
That means restoring the riparian area of the Guadalupe can play a key role in not only helping it recover, but helping it be more resilient in the future.
It’s a long story and a good read. It was in the Express News (published on December 15) so I can’t give you a gift link, but I was able to view it by accessing the story link in Incognito mode in Chrome. It was in the print edition of the Chronicle – front page, in fact – on December 29.
Anyway, the bottom line is that everyone expects the river to recover; multiple people pointed to the Blanco River flood from 2015, which had similar environmental effects but which is largely unnoticeable now. The main thing people can do to help is to plant seeds for native flora, to help speed up that part of the recovery and to ensure that the river has solid natural borders and drainage. The San Antonio Botanical Garden is spearheading such an effort, to plant over 250K native seeds in the hope of growing the 50K replacement trees that are needed. The Texas Parks & Wildlife Department (TPWD) and the Upper Guadalupe River Authority have a joint project to work with the landowners along the river – about 94% of the riparian area is privately owned – to ensure that they do their part as well. All in all, I got a good feeling from this that while the Guadalupe River has changed due to the flood, it will still be what it has always been.