Work is underway on a maintenance project taking place at Rio Vista Falls.
The work began on the construction project in October and will address instream structures and bank improvements. Underwater voids and undercuts have formed in the bank and instream structures throughout the Rio Vista Falls area and require maintenance, the city previously said.
According to City of San Marcos Senior Engineer Greg Schwarz, the site has been secured with fencing and rope-connected safety buoys within the San Marcos River. A turbidity curtain has been installed in the river downstream of the construction work to capture suspended sediment that could be produced as work continues, Schwarz added.
Currently, Austin Filter Systems, Inc. Construction — the contractor for the project — is installing components to dewater the area in order for equipment to access the river and begin maintenance work, Schwarz said. Work is being done in coordination with federally permitted biologists in order to remove and relocate aquatic fauna including the endangered — federally/state listed — fountain darter where dewatering activities are taking place. Additionally, any federal and state protected Texas wild rice in the area will be removed, housed and replanted near its original location after construction is completed, Schwarz added.
The contractor is currently working on a part of the dewatering process, which includes installing temporary pipe extensions to two existing 4-foot diameter pipes which will be used to divert river flow around the falls area. Schwarz said the existing pipes are located below ground along the east bank and begin at the dam area. The pipes end just upstream of the Cheatham Street Bridge. The pipe extensions will transfer and divert river flow discharge to the downstream side of the Cheatham Street bridge, Schwarz said, adding that a rock gabion splash pad will be installed to protect against erosion and a coffer dam will be installed to prevent backwater from the river from entering the construction site.
Schwarz said the full dewatering process is expected to last another week and a half.
