Kevin Baxter | Staff Reporter
The maintenance on Rio Vista Falls began in October 2021 and was expected to finish in March of 2022. Due to unexpected delays, the project is still ongoing and anticipated to be complete in May, according to the contractor’s, Austin Filter Systems inc., estimate.
According to Greg Schwarz, Civil Engineer for the City of San Marcos, acts of vandalism have contributed to delays in the project.
“On a number of occasions, when the contractor had slipped away for the day and then come back in the next morning, he has found the barriers had been slashed and the water ends up getting back into the site,” said Schwarz. “Or there are tabs on these barriers, several openings that have tabs that allow you to fill them with water. There was an occasion where those were removed and all the water had basically flooded the site.”
After these acts of vandalism cause the site to fill with water again, the barriers have to be repaired and reset. The biological staff also has to come back to the site to conduct sweeps for fish and aquatic life again. This causes delays and adds to the overall cost of the project whenever this happens, according to Schwarz.
The biological staff monitors the area and scouts the site for aquatic life whenever the area is set to be dewatered. If found, the life will be gathered and relocated to another part of the river. This is one of the measures taken to protect the local environment and wildlife of the project area and must be done to satisfy the permit for the project.
“The contractor has particular practices that he’s required to use when he’s working around the river. One of the items is that the hydraulic fluid for the machinery is biodegradable,” Schwarz explained. “Also, he’s required to have spill kits on-site and readily available. In case there is a spill, he’s able to clean it and address it quickly.”
Schwarz also explained that the contractor has some measures that are taken on-site to prevent soil erosion from entering the river.
“The contractor does pump water to remove it from the area. Sometimes, if that water has a lot of sediment in it, he directs it to an area that filters out the sediment before it’s released back into the river,” said Schwarz.
Schwarz described other unexpected setbacks that may have contributed to the delay.
According to Schwarz, the flow of the river was a bit higher than average. When the gates to allow flow through the four-foot diameter pipes to divert the river was opened, water was still flowing over the dam.
“The contractor had to build a little wall on top of the dam to keep the water from coming over the dam and force it into those diversion pipes,” Schwarz stated.
There was also more maintenance that had to be done than originally expected. Schwarz did explain that this wasn’t a big surprise because it is difficult to thoroughly inspect the site before the water is drained.
“There were additional areas that we stabilized. We added more stonework in order to stabilize banks and provide a more robust river system in that area,” said Schwarz.
The last unexpected issue Schwarz said they encountered was that there had been some leaks in the underground diversion pipes used to drain the section of the river. The leaks were making their way into the river.
“We had to address that and that took some effort to investigate it and to repair it. So that was another thing that wasn’t anticipated and we dealt with,” said Schwarz.
Schwarz added that after the maintenance at Rio Vista Falls is complete the contractor will then work on some maintenance at Dog Beach.
“It’s an access point that is all limestone block and there are some failures occurring right where the limestone block interfaces with the river,” said Schwarz “The contractor is going to go in and add some additional stonework and do some repairs at that location.”
The maintenance at Dog Beach is a much smaller effort than that at Rio Vista Falls, according to Schwarz. The maintenance at Dog Beach will not take nearly as long as it has at Rio Vista Falls and will only block off half of the river.