I love Barton Creek. It’s one of my favorite things in Austin. I don’t mean the Springs—though I like those too. I mean the Creek. The whole Greenbelt span of it, from the Hill of Life in to downtown.
The year I moved here—last year, 2019—the creek got full in the spring. I’m not sure what caused this. I mean, I know it was rain, but I don’t know which rain exactly. Is it all about recent rainfall? Does the level of the water table have something to do with it? Is the level of the water table a thing?
With it raining today, I got curious. Every time it rains in Austin, I tell myself it’s helping fill up the creek for next spring. It’s exciting. I picture an April Saturday, packing a few little coolers (easier to distribute the weight), taking an uber over to the Hill of Life, spending the day working our way downstream past Sculpture Falls and Twin Falls and those cliffs between MoPac and South Lamar, swimming and drinking and maybe popping out for Tacodeli for lunch, then taking a nap at Zilker before (insert preferred evening and night activity). I tell myself this rain is helping bring that Saturday to life.
I don’t know if it’s true, though. I don’t know if the rain now impacts the creek’s water level in April. So I decided to check.
The Internet™ didn’t give me much in the way of information. If you’re curious at any given time whether Barton Creek is, in the moment, good to swim in, Serena Nguyen has a website devoted to that specific purpose, but I couldn’t find any future forecasts of Barton Creek’s water level, or even some science-y site explaining how many years of rainfall impact the height of rivers and their underlings in a given watershed.
I turned to the numbers.
Weather Underground has historical data on how much rain’s fallen in a place in a given month. For Austin, it uses the airport, which might not be the most representative spot for Barton Creek—being on the opposite side of town (Barton Creek’s headwaters are out just north of Dripping Springs, and it winds through Hays County for a bit before coming into town)—but seems like it’d be close enough. Specifically, I was curious if the heavy rainfall in fall of 2018 impacted the creek’s level in the spring of ’19. So in addition to the monthly precipitation, I pulled running three-month, six-month, and twelve-month totals.
| Month | Year | Precipitation (in.) | 3-month precipitation total (in.) | 6-month precipitation total (in.) | 12-month precipitation total (in.) |
| May | 2018 | 3.23 | – | – | – |
| June | 2018 | 0.62 | – | – | – |
| July | 2018 | 1.26 | 5.11 | – | – |
| August | 2018 | 0.84 | 2.72 | – | – |
| September | 2018 | 5.59 | 7.69 | – | – |
| October | 2018 | 6.63 | 13.06 | 18.17 | – |
| November | 2018 | 2.87 | 15.09 | 17.81 | – |
| December | 2018 | 6.37 | 15.87 | 23.56 | – |
| January | 2019 | 3.25 | 12.49 | 25.55 | – |
| February | 2019 | 0.58 | 10.20 | 25.29 | – |
| March | 2019 | 0.52 | 4.35 | 20.22 | – |
| April | 2019 | 5.59 | 6.69 | 19.18 | 37.35 |
| May | 2019 | 8.40 | 14.51 | 24.71 | 42.52 |
| June | 2019 | 5.55 | 19.54 | 23.89 | 47.45 |
| July | 2019 | 0.04 | 13.99 | 20.68 | 46.23 |
| August | 2019 | 0.04 | 5.63 | 20.14 | 45.43 |
| September | 2019 | 0.18 | 0.26 | 19.80 | 40.02 |
| October | 2019 | 2.70 | 2.92 | 16.91 | 36.09 |
| November | 2019 | 0.62 | 3.50 | 9.13 | 33.84 |
| December | 2019 | 0.78 | 4.10 | 4.36 | 28.25 |
| January | 2020 | 2.21 | 3.61 | 6.53 | 27.21 |
| February | 2020 | 1.73 | 4.72 | 8.22 | 28.36 |
| March | 2020 | 3.69 | 7.63 | 11.73 | 31.53 |
| April | 2020 | 4.05 | 9.47 | 13.08 | 29.99 |
| May | 2020 | 8.90 | 16.64 | 21.36 | 30.49 |
| June | 2020 | 2.53 | 15.48 | 23.11 | 27.47 |
| July | 2020 | 0.65 | 12.08 | 21.55 | 28.08 |
| August | 2020 | 1.30 | 4.48 | 21.12 | 29.34 |
| September | 2020 | 6.54 | 8.49 | 23.97 | 35.70 |
| October | 2020 | 0.34 | 8.18 | 20.26 | 33.34 |
| November | 2020 | 0.83 | 7.71 | 12.19 | 33.55 |
| December (incomplete) | 2020 | 3.06 | 4.23 | 12.72 | 35.83 |
The answers are…inconclusive. I know that in August of ’19, for example, the creek was not running its full distance. There were breaks. And yet that August’s twelve and six-month totals are relatively high, while April of that year (when the creek was in full force) has a low three-month total.
This doesn’t even point to an explanation, because it could mean this is a lot simpler (a two-week total, perhaps) and it could mean this is a lot more complicated (maybe years of water table data combined with recent precipitation, with an added adjustment for temperature and humidity to take stock of how much the creek’s evaporating while it flows). In short, Barton Creek remains a mystery, and I don’t know whether today’s rain is going to make any difference come April. I have received an answer to my question, and the answer is that I cannot know.
Sometimes nature wins.
