Austin’s Blackland Prairie remains unexpectedly unrecovered

On Wednesday, graduate engineer Lindsay Olinde and Mateo Scoggins, a senior environmental scientist from the Watershed Protection Department, presented the Environmental Commission with the unexpected findings on Blackland Prairie riparian corridors.

Contrary to the hypothesis that this historically less-urbanized and – protected watershed would be covered in woody wetland vegetation, it appeared that there is even poorer vegetation there than in urban settings with more impervious cover.

Unlike the portion of Austin’s watershed located on the Edwards Plateau, the Blackland Prairie does not benefit from a long history of studies on its environment. Originally 12 million acres, according to Olinde, only 1 percent remains undisturbed. Furthermore, there is little in the way of reference for how the other 99 percent of the Blackland Prairie once was.

Scoggins said that essentially “we have the literature of explorers in Texas documenting what they saw, and that is the best reference that we have.” The documentation does indicate that the riparian zones of the Blackland Prairie were heavily vegetated.

With such a scant historical picture for reference and booming development spanning the east side, the Watershed Protection Department is racing to prioritize and tailor conservation efforts to the Blackland Prairie’s riparian corridors. Olinde said the question boils down to: “Are the policies we’ve developed through past studies sufficient in this area also?”

The answer is probably not yet.

In 2010, when the city was putting together the Watershed Protection Ordinance, creeks on the east side of town did not receive the same degree of protection that those in the west did. Today, though, Matt Hollon, the acting planning division manager for the Watershed Protection Department, said there are 363 miles of headwater buffers in the east as well as a more stringent set of requirements for those who wish to modify the floodplain environment.

In such a highly erosive environment like the Blackland Prairie, he emphasized the need for cautious mitigation, because “it’s much easier to protect (creeks) now than to have to go back.”

Commissioner Wendy Gordon responded by questioning if check dams were part of the issue.

Scoggins answered, “We went to 50 sites; we found zero grade controls. I’m sure they’re out there. In this scenario though, any kind of stable structural thing is going to be a good thing.” According to him, the most developed site the department has visited had 7 percent impervious cover.

This recommendation seems contrary to the mindset of years past, when the consensus was that no land management is good land management for vegetation re-establishment, even if it takes decades. Olinde said, “We were really surprised to see that a lot of the sites had nothing, even if they weren’t being managed.”

Scoggins offered an alternative view on the lack of historically present wetland vegetation, saying, “Vegetatively it will recover, but not as a wetland.”

The only exception to these findings is in the Walter E. Long Park zone, which the department says merits further investigation.

The hope is that these findings will encourage active restoration. However, to accomplish any repairs, the Watershed Protection Department will have to rely on public-private outreach because much of the land on the city’s Blackland Prairie is privately owned. Furthermore, much of the land that needs to be restored and retrofitted lies outside of the city of Austin’s jurisdiction, and the Watershed Protection Department will, therefore, need to collaborate with the state, county and various stakeholder conservation groups in the area.

Despite the perceived difficulties with the active restoration of the Blackland Prairie, Commissioner Linda Gurrero said, “We really need to move toward that word ‘requirement’ and away from ‘incentive’ because we’re getting into a critical situation.”

Commissioner Pam Thompson had a different view on the effort and commented, “I appreciate the fact that you’re doing this study, but it’s kind of after the fact.”

Even so, the Watershed Protection Department plans on forging forward. Scoggins finished by addressing the commission, saying, “We’ll commit to coming back within the year to bring you back a programmatic approach.”

Photo of North Fork Dry Creek from the city of Austin presentation.

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