Spooky Old Adits

We wanted to share a spooky tale from the Calaveras Dam Replacement Project. It seems even state-of-the-art construction projects aren’t without their spooky places.

While moving the rock and soil to make space for the new replacement Calaveras Dam, workers uncovered what looked like holes dug into the area surrounding the existing dam.

The holes are actually adits excavated by the builders of the first Calaveras Dam. 

Technically, an adit is an entrance or tunnel into a mine. Back in the early 1900’s the best way engineers had to explore the rock and soil for a damsite was to excavate adits to look at the underground geology. There are 16 total adits that were uncovered at the site.

We knew about the presence of these adits before we started to dig for the new dam foundation. However, it didn’t ease the creepy feeling workers had when they uncovered them. And some even claim equipment broke down and didn’t work properly while they were working around the adits, as if they were haunted.

The adits are mapped and filled in with concrete or rock to stabilize the ground prior to constructing the new dam on top, and to seal in any spooks that might be still be there…just in time for Halloween!