Thursday, January 16, 2014

Photo Essay: What's Left of the St. Francis Dam

What's left of the greatest American civil engineering failure ever? Of the second worst disaster in California history?

Some chunks of concrete, some rusty rebar, and a scar in the canyon wall.



The St. Francis Dam was built by William Mulholland (at that point, a widely-known, successful engineer for LA's water wars) in 1928 to wall off a reservoir full of an emergency water supply, as fed by the LA Aqueduct, which had opened 15 years earlier.  Mulholland's first choice in terms of location was Big Tujunga Canyon, but former LA mayor Fred Eaton priced him out of the area. Mulholland instead chose San Francisquito Canyon - at the time, out in the middle of nowhere, and, unbeknownst to him, on unstable ground.



San Francisquito Canyon Road was built to go right past the dam site through the canyon, past all of the rubble, but it was washed out in the early 2000s by rain, and thereafter decommissioned, replaced by a rerouted new road.



You can walk down to the dam site down this "Old" San Francisquito Canyon Road, which is now closed to traffic. Signs indicate a rock slide area. No kidding. (More on that later...)



Although the road has only been closed for a few years, nature is starting to take over.



It winds down the canyon, and starts to resemble a hiking trail, with tree overgrowth and an advancing dirt shoulder.



The road soon opens up to a curve...



...and as you follow the curve, you approach the original site of the dam, walking through the empty bowl of the former reservoir, which was once full of 12 billion gallons of water.



You soon reach a pile of rubble, the remains of the last standing piece of St. Francis Dam, a 200-foot tall piece of the center section that didn't topple with the rest of it.



Nicknamed "The Tombstone," that last standing piece became an eyesore, and an embarrassing reminder of the tragedy that hit the area: a wall of water, 180 feet high, which claimed over 450 lives (perhaps many more, given the undocumented immigrant workers camping nearby) and took everything - livestock, trees, buildings - in its path out to the Pacific Ocean.



Months after all the water had emptied from the reservoir, the Tombstone took the final life in the disaster's death toll: a young boy who'd climbed to the top, gotten spooked by a friend, and fell to his death. After that, the Tombstone was dynamited.



All that remains now is a lot of rebar...



...and a pile of rubble.



Some larger chunks of rebar-filled concrete remain...



...but the pile itself has dramatically diminished in size over the years...



...having attracted lots of hikers and looky-loos, who've walked on top of it...



...flattening it...



...and grinding its pieces into a fine dust.



Plants now sprout up amongst the remains...



...and pools of water collect in the shady areas behind the rubble.



It's hard to imagine what the dam looked like before it broke...



...but you get an inkling of its massive size, just based on how much concrete remains of just that one piece.



Although the remains are visible from Old San Francisquito Canyon Road (and can be hiked down to), to really understand the scale and positioning of the dam, you have to look up to each side, at each canyon wall, both of which bear the scars of the former dam.



On the west side, you can actually climb up a ridge to get a better view from above...



...where you encounter larger pieces of concrete that have disintegrated less, and retained much of their original integrity.



At the top of the steep ridge, you encounter the best-preserved section of the St. Francis Dam:



...the 588-foot long wing dike built to join the west abutment of the dam...



...in order to accommodate a ten-foot increase in the dam's height from its original 1923 plan.



The height increase was one of Chief Engineer William Mulholland's many decisions that may have contributed to (or certainly didn't prevent) the disaster's occurrence, though movement from an ancient Paleolithic landslide in the schist rock (along what is now known as the San Francisquito Canyon Fault) was the immediate catalyst to the dam break, moments before midnight on March 12, 1928.



On top of the ridge, you can look down into the basin below, through which San Francisquito Canyon Road (the new one) now runs, and imagine everything underwater.



You can walk pretty far out along the wall...



...which thankfully hasn't fallen prey to vandals and thieves.



If you turn right, you face south, and downstream from the flood...



...which carried with it giant chunks of the dam, some as far as a mile down canyon, some much farther.

Stay tuned for further exploration of the Old San Francisquito Canyon Road, and discovery of more pieces of the dam, farther downstream.

Related Posts:
Photo Essay: The Power Plants of the St. Francis Dam Disaster
EVENT: Explore the St. Francis Dam Disaster Site & LA Aqueduct
Photo Essay: Lake Hollywood Reservoir