Panther Hollow

Downstream effects of construction of River Place Section 16, Panther Hollow Creek at Big View Drive on Lake Austin.

The following photos illustrate the downstream effects of storm water erosion and sedimentation derived from road and bridge construction in the critical water quality zone or flood plain of a waterway.

Construction of Big View Drive across Panther Hollow Creek. The creek just downstream becomes an “arm” of Lake Austin. Construction crew kicks the soccer ball after a days work on the road.

Construction of Big View Drive in November of 2001. Note the dirt haul road across the metal culverts in Panther Hollow Creek.

Panther Hollow Creek immediately downstream of Big View Drive on Jan 18, 2002. The huge puddle and the pile of twisted metal are what remain of the temporary culvert and construction road into the rest of the River Place section 16 infrastructure development project.

Big View Drive bridge over Panther Hollow Creek on January 18, 2002. A mudhole is where the haul road used to be. A water quality wet pond on the other side of the road (hidden) is draining through a pipe under the road and appears as clear water in the foreground. The only thing separating the mudhole and the construction debris from the clear creek is the silt fence over the rock berm on the left side of the photo.

A coarse sediment and rock bar below the redundant temporary rock berm mitigation for the construction of the Big View Drive bridge over Panther Hollow Creek.

Looking upstream at Big View bridge construction from further downstream. Notice the long construction debris gravel bank in the bed of Panther Hollow Creek

Looking further downstream at construction debris washing around the bend in Panther Hollow. The Cladophora Algae bloom in the lower left corner of the photo indicates drainage of nutrient laden water derived from golf course fertilization and irrigation with treated effluent upstream above the wet pond.

Downstream terminous of construction debris gravel bar in Panther Hollow Creek … center of photo, 18 Jan 02.

Erosion of recent sediment deposits in Panther Hollow Arm derived from November 2001 storms. Lake Austin has been lowered for weed control and thus we see the bed of the arm of the lake. Hydrilla and milfoil are dried out in thick layers on the higher banks of Panther Hollow now.

Panther Hollow Creek emptying into Lake Austin (lowered for Hydrilla and milfoil water weed control activities.) Note the erosion of recent sediment deposits in stages as water in Panther Hollow Arm of the lake was lowered.

Confluence of Panther Hollow Creek/Arm with Lake Austin. Notice the delta of mud and sand just beneath the water surface extending some distance out into the lake.

Notice the delta of mud and sand from River Place construction in Lake Austin. Also notice the snag stuck in the sand bar and the very invasive hydrilla and milfoil water weed along the shore of the lake as well as dried up on the bank.

These are the downstream effects of improperly mitigated construction activity. This, combined with fertilized golf course and lawn stormwater runoff as well as poor boating behavior results in the infestation of invasive weeds in the Lake Austin watershed. We are witnessing the eutrification of this recreational lake and water supply reservoir serving the City of Austin, Texas.