Shoal Creek suffers from acts of omission, not commission. There are exceptions, but in general Shoal Creek has been seen as a void to fill with the detritus of urban life. Let’s look at the detritus.
Shoal Creek once ran as vigorously as Barton Creek. Developers once eyed Seider’s Springs for a lakeside development. The steady flows are gone, victimized by development and myopic public works projects.
This is a solution masked as a problem. Little of Shoal Creek’s stormwater is detained up stream. Most is straight piped into the creek. Austin is beginning to look more closely at sustainable stormwater management, but you wouldn’t know it by looking at the creek.
Pollution is drained into the creek by stormwater. The water washing over streets, bridges, parking lots, and back yards reaches the creek unfiltered. Every dog pile left along Shoal Creek will finally make its way to your drinking water. Fertilizer seeps into the creek as well, feeding the various blooms and rank vegetation.
As mentioned above, increased stormwater velocities have left streambanks undermined and eroding.
The drought of 2011 exposed the creek in ways I had not seen before in my 17 years of living along the creek. Every screwy idea implemented in the past has been on display. The pièce de résistance is the waste water pipe running down the center of the creek bed (look for the concrete box). Below West 3rd you see the remnants of the Green Water Treatment Plant, the Seaholm Power Plant, and the diversion of the mouth of Shoal Creek at Lady Bird Lake. Yes, these are acts of commission.
Shoal Creek is a ribbon of green bisecting one of America’s fastest growing cities. The trees and shrubs that border the creek provide wildlife with a corridor of essential habitat. The value of this corridor is directly related to its continuity. Development threatens to interrupt this ecological continuum, creating sections across which wildlife will not or cannot pass.
Trust me; none of these challenges is insolvable. There are solutions for every conundrum. The question is whether or not we (we as in Austin) have the will. Let’s start over.
The same approach addresses these five problems – sustainable stormwater management. I love Portland’s approach – maximize permeability, minimize offsite storage. Detention ponds, bioremediation wetlands, stormwater swales, rain gardens, and structural soil all have a role in sustainable stormwater management. What is not needed is more straight pipes to the creek. The goal should be to trap every gallon of water upstream, and then to slowly release it downstream to insure a sustainable low flow. Develop enough retention (in its broadest sense) to capture the 10-year maximum rainfall event.
I suspect that detention and retention will not be enough to sustain a low flow. Therefore we need to work with the city to redirect water from Lady Bird Lake to Shoal Creek. No, I am not envisioning the San Antonio River Walk. But surely we can find a way to pump water from the lake to a point up Shoal Creek (West 24th, for example?) and then let that water flow back.
As for trash, the solution is simple. Let’s keep our crap out of the creek. No one forces us to fling garbage into the creek. There is no gun held to our heads. If a dog craps, clean it up. If you are finished with your half gallon of Jack Daniels, throw the bottle into the receptacle.
Bad ideas can be erased by good ideas. Begin with the simple notion that stormwater can be a design element. Develop a sustainable trail system, one that limits runoff from hardened trail surfaces and uses structural soil to increase permeability. Use retention ponds and vegetated swales as enhancements for wildlife, recreation, and education. Use low level overflow dams for in-stream detention and for creating more permanent pools within the creek itself. In time of drought, these pools are critically important for wildlife. Remove old structures from the creek, vegetation from within the stream bed, and shoaling that now restricts flows. Protect the wildlife corridor, and enforce setback regulations. Revegetate areas where the corridor has been severed.
Let’s keep our crap out of the creek
The initial goal should be to bring Shoal Creek back to robust health. A restored creek then offers a platform for the types of enhancements that people expect of a world-class city. The next section (Visioning Shoal Creek) will offer suggestions about such enhancements.