What Would Happen If Chabot Dam in the East Bay Hills Broke Open?
What would happen if chicago damn cracked open an empty the lake behind it onto neighborhoods in san leandro and east oakland. It's an alarming thought. We asked cake. Ud's dan bricky. Who's reported on safety issues at california's oroville dam to find the answer. Holly and vickers kings question is a really good one because it reminds us that all dams pose risks of some kind given the nature of the job they perform holding back huge volumes of water they can turn from placid lake into deadly torrent. If unleashed all at once. They deserve very close attention. When that attention lapses catastrophes can do happen in late may eighteen eighty nine flood. Water overflowed badly maintained private dam in western pennsylvania. Triggering its collapse. A wall of water race down the valley below a century later. Historian david mccullough said. The johnstown flood was so vividly alive in the local consciousness. I grew up in western pennsylvania. I'd heard about the johnstown flood my whole life as children. We used to shout run for the hills. The damas busted little knowing what real terror is in those words. The flood wiped entire towns off the map and killed twenty. Two hundred people in california owns its own special chapter in the history of dam disasters with a tragedy that unfolded more than ninety years ago in a remote canyon fifty miles north of downtown los angeles from the day. The saint francis dam opened in one thousand nine hundred twenty six. It leaked the folks in the farm. Towns downstream used to joke. They'd see you later if the damn don't break on march twelfth nine hundred twenty eight. The saint francis damn disintegrated just hours after it was pronounced sound by los angeles water. Chief william mulholland who had designed and built the two year old structure when the massive concrete dam broke apart water raised more than fifty miles to the pacific ocean killing about four hundred fifty people along the way but those events one hundred thirty years ago in johnstown ninety some years ago in los angeles county sound like ancient history much more recently california. Got a lesson in how dangerous and costly failure of even part of a major dam can be failure ambiance spillway structure results in an uncontrolled. Lisa flood waters from link oroville and eating evacuation from the low twenty. Seventeen collapse the spillway at oroville dam in the northern sierra foothills one hundred thirty miles northeast of san francisco touched off a series of events that lead local officials to order one hundred eighty eight thousand people to flee their homes. This is not a drill. Repeat this is not a drill. Spill ways are crucial to preventing overtopping. That's what happens. When a reservoir rises over the top of the dam and simply spills over a spillway is like an emergency valve. Damn managers can open to safely release water from a reservoir bills over the top but back in february twenty seventeen oroville dam spillway began to disintegrate just as a series of winter storms dumped huge amounts of rain across northern california without a fully functioning. Spillway lake oroville rose rapidly water poured over a hillside that was supposed to serve as an emergency spillway. That emergency spillway began to fail to leading to the mass evacuation. In the aftermath investigators found the emergency spillway was ill conceived and the main spillway was badly designed poorly built and inadequately maintained. So how is should bowe damn different from all those bad dams and what does east bay mud have to say about. Chaba cracking open and unleashing catastrophe on the east bay. Simple answer to that question is that the dam would never crack open. That's jimmy yolly east bay mud director of engineering and chief damn safety officer he oversees the district twenty six times including chabad. Damn the reality is that the dams are designed such that. They don't just crack open. You will see signs of a failure if one is to occur and The dan's designs with monitoring equipment to make sure that you can see that happening if it was a east bay mud confidence that a dam built within a quarter mile of a dangerous fault will stand up to violent shaking. Let's take a look at how the dam was first built. Nearly one hundred fifty years ago and how it's been maintained since