June 9, 2010: the deluge

June 9, 2010 around 3 AM… Along with many other Austinites, we were rudely awakened by a spectacular show by mother Nature. Thunder was crashing and lightening was flashing…sometimes seemingly directly above our house. And the rain, rain rain! Later that morning I checked the satellite radar and saw intense, dark red cells…I’m sure one of them hovered over our part of Austin.

We live in the neighborhood directly east of Robinson Ranch; the headwaters of Walnut Creek are behind our house. Since the drought (last 2 years) it has been a wet-weather creek, dry unless there is significant rain. We had significant rain in the wee hours of June 9…about 3.3 inches per the rain gauge.

The creek was somewhat full (though nowhere near the highest we’ve seen it) and running fast. I wondered what our monitoring site was like…so around 11 AM I investigated.  On the way, I stopped where the stream bed crosses Oak Creek Drive just west of at MoPac (behind MoPac Storage). Wow!

The day before at the Oak Creek bridge, the stream bed (which is 30-40 ft wide) was bone dry. Not now. It is full of fast-rushing water. Hmmmmm, wonder how high the water will be at the sample site?

The usual sample site is a pool roughly a meter deep, which is just below a stream that is roughly 6 inches deep, if that. A hiking trail crosses the stream and normally some crossing rocks are visible and dry so people can cross the stream without getting their feet wet.

Not today.

The crossing rocks weren’t even visible and the sample site’s exact location could barely be seen, the water was so high.

Upstream, the water under the bridge was wide and muddy. I’ve never seen it that wide! Usually it’s a wide, quiet stream that meanders down to the sample site with a current that isn’t noticeable until the stream bed narrows. Not now.

A bit further upstream, the normally small waterfall was a torrent. It reminded me of some of the rapids on the Guadalupe – had it been a bit deeper it would have been fun to kayak.

While driving home I wondered what was happening elsewhere along the creek. So I made a detour to the bridge on Council Bluff, the closest street to Robinson Ranch (north side of Parmer about 3/4 miles west of MoPac). Normally dry, it also had plenty of water, which flows through some backyards in the Northwood subdivision of homes (including ours), then past Oak Creek and eventually to the sample site.

When I took these photos it was still drizzling. The rain stopped midday and the sun came out by mid afternoon. The rushing river subsided quickly after the rain stopped. I took some more photos to show the change. Again, wow – it’s amazing how fast Ma Nature can change her moods. And a few days later, the creek bed behind the homes was dry again.

water flowing to Council Bluff bridge next to Robinson Ranch (normally this is dry or at best has a trickle of water)

stream flowing to Council Bluff bridge from Robinson Ranch

Stream flowing downstream from Council Bluff bridge. Normally this is dry or just a trickle.

looking downstream from Council Bluff bridge

The creek behind houses about 1/4 east of Council Bluff. At the top of the photo there’s often a pond then it is dry.

The creek behind the next downstream house…

The next public site to see the stream after Council Bluff is Oak Creek Dr.; this is the results of the 3.3″ rain heading to the Oak Creek bridge.

Upstream and next to the Oak Creek bridge there’s actually a tiny waterfall.

And the flow continues downstream from the Oak Creek bridge…

…eventually passing under Waters Park Rd. This is adjacent to MoPac, near the end of Amherst. It’s also across MoPac from the hospital.

From the road (bridge) I see that the sample site is totally submerged!

Another shot of the sample site from the Metric bridge.

The sample site & downstream from the road

A closeup of the sample site from the road

Another view of the flooded sample site.

The trail rocks are covered and the water covers some vegetation.

Another shot of the flooded sample site with the edge of the bridge included.

The sample site and the north bank.

From the south bank looking under & past the bridge – much more water than usual!

Much more water than usual under the bridge. wow!

Another view of water under and beyond the bridge…

Plenty of muddy water between the bridge and trail rocks

…and a torrent of water above the bridge!

4 hours later, the rain has stopped and the flow through the back yards is less.

Just downstream from the prior photo the sream is still fairly wide…

…and behind the next house the stream narrows even more.

4 days later the creek is dry again except for the pond at the top of the photo

4 days later – dry backyard creek

4 days later, behind the next house, the creek is completely dry again and the deer are checking it out.