Posted: Fri, 4 Jun 2010 08:03 AM - 13,917 Readers

By: Tiffany Young

Unbeknown to many Lake Travis visitors, hundreds of feet under where they swim and boat are some of the remnants of the plant that helped construct the lake. The Shaker Plant, which is about 100 to 150 feet under water when the lake is full, was built in the late 1930s to assist in the construction of Mansfield Dam.

Mansfield Dam is made of concrete, which is made of three components: sand, cement and aggregate. At the Shaker Plant, rocks would be separated into different sizes, which were then transported to the dam for concrete.

Jeff Eichelberger, a scuba diver, has become known as the unofficial Shaker Plant expert to the local diving community as well as the Lower Colorado River

Authority. When a friend of his was looking for a bridge near the lake that she was told by friends did not exist, Eichelberger decided to investigate and ended up finding a wealth of historical photos at LCRA’s website. Not only did he find the bridge she was looking for in one of the photos, but he also became fascinated with some of the pictures he found from the 1930s of the building of Mansfield Dam, formerly Marshall Ford Dam, many of which included shots of the Shaker Plant.

While he and other divers knew the plant existed and had already explored some of its remnants—which can be found along a ridge at about 600 elevations—they had not seen photographs of the plant while it was in use.

The company who had constructed the Shaker Plant, Brown and Root-McKenzie Construction Co. of Houston, had taken photos of the project, but when Eichelberger asked them about the history, they said they had thrown out the files about 10 years earlier.

Supplied with only photos, Eichelberger began trying to find out more about the plant and used enlargements of photos and maps to plot its locations and elevations, which helps divers when they are exploring under water. For instance, they sometimes take laminated photocopies of maps and photos from the 1930s under water so they can identify what they are seeing.

Much of the material that could be reused or was easily transportable was taken away from the plant when the dam was complete to be used for other projects, but much of the foundation can still be found. Also, pieces of a conveyor belt that transported rocks can still be found, but is old and brittle from being under water for 70 years, which causes it to crumble at the touch of a hand, Eichelberger said.

While the plant is believed to only have been running for a few years, what’s left of it is expected to be a place of exploration for divers and fish for years to come.

Timeline:

1935 — A flood that covered downtown jump-started the formation of the Lower Colorado River Authority
1936 — Began building the Shaker Plant
1937 — Began construction of Marshall Ford Dam, now Mansfield Dam
1938 — Another big flood put LCRA behind in construction of Mansfield Dam
1941 — Completion of the dam and opening of the Highland Lakes