Motorists are noticing “mystery water” flowing through one of the bores of the Caldecott Tunnel, which is raising concerns about the tunnel’s structural integrity, but Caltrans insists this can be fixed with a little drainage work.

Something unusual is happening in State Route 24’s “gateway to Orinda,” the Caldecott Tunnel. As KTVU reports, there’s “a mystery surrounding water flowing” through Bore 1 of the tunnel, despite the lack of any significant rain in quite some time. Caltrans has also placed an electronic sign alerting motorists of the water, and some people are of course freaking out on Nextdoor whether this indicates structural problems for the tunnel.

But Caltrans insists it’s nothing to worry about, and is only happening because of excess water from the winter’s heavy rains.  

"The water is basically seepage, which is runoff from the rain we continually had earlier this year, and this is the water coming down from the hillside," Caltrans spokesperson Bart Ney tells KTVU.

That all sounds like a normal issue. But it shouldn’t be happening, and speaks to some aging infrastructure within the tunnel. That water is flowing as it ought to be, but it should not be accumulating, and the aging drains can’t handle the flow.

"They're just so significantly clogged that we're going to have to do something a little more robust," according to Ney.

The answer? More water! Caltrans feels the drains can simply be unclogged of debris and a calcium buildup with some water jet spraying, which they plan to do during low-traffic nighttime hours as soon as next week.  

Related: Gang Of Rogue Goats Appear Near Caldecott Tunnel [SFist]

Image: Pi.1415926535 via Wikimedia Commons