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Broken Canal Floods Riverdale
Do Other Homes Face The Same Risk?
Riverdale City Flood Web Site
August 2, 1999
State inspectors say the concrete lining in the canal that burst over a Riverdale neighborhood is nearly a century old and in bad shape. And if it's not replaced, it won't be safe.
Environment Specialist John Hollenhorst has details.
The specifics of what caused the collapse are still under investigation. But State inspectors say it's clear that much of the concrete lining is in terrible shape, and the type of soil it was built on makes a very poor foundation for a canal.
At the part of the canal where disaster struck, they're drilling holes to get answers. Contractors are working for the canal owners' insurance company.
They're temporarily resisting a National Guard plan to re-landscape the jagged gulch. One of the mysteries they'd like to explain first is a puddle, a slow trickle of water. Did it somehow contribute to disaster?
FLOYD BAHAM/CANAL COMPANY PRESIDENT: "AND I THINK WHAT WE WANT TO DO IS TRY TO FIND OUT WHERE IT'S COMING FROM BEFORE ALL OF A SUDDEN SOMEBODY WANTS TO COME IN AND COVER THIS HOLE UP."
Meanwhile, a state inspection team began probing the rest of the canal. They walked and measured and poked at more than a mile of concrete-liner built in 1910. And they were not impressed.
RICK HALL/STATE DAM SAFETY INSPECTOR: "THERE'S A LOT OF DISPLACEMENT, CRACKING OF THE CONCRETE. MISSING CONCRETE."
In fact, the overall condition is so poor, the state's top dam safety expert doesn't think a simple fix at the broken part of the canal will be good enough.
RICK HALL/STATE DAM SAFETY CHIEF: "I THINK IN THE LONG-RUN, THEY DEFINITELY NEED TO REPLACE THIS CANAL. EITHER RELINE IT, OR PUT IT IN A PIPELINE."
By walling off the broken part of the canal, they've been able to use the rest of the canal to deliver water to farmers and homeowners. The state has a politically tricky question to answer: Is the canal safe enough to carry water?
RICK HALL/STATE DAM SAFETY CHIEF: "I WOULD PROBABLY BE CONSERVATIVE AND PLAY IT SAFE, IF I HAD TO STAMP IT, AND SAY 'DON'T PUT WATER IN IT.' BUT THAT'S JUST FROM MY STANDPOINT."
FLOYD BAHAM/CANAL COMPANY PRESIDENT: "IS THE CANAL BROKEN UP IN PLACES? ABSOLUTELY. BUT DOES THAT MEAN THAT, BECAUSE THIS WAS CONCRETED AT ONE TIME, THAT IT'S ANY MORE DANGEROUS THAN THE CANALS THAT ARE IN THE STATE HERE THAT HAVE NO CONCRETE WHATSOEVER? "
It's true. Most canals have no concrete, and are just trenches dug in the ground.
But the state inspector says they're usually built on waterproof clay. The Davis-Weber Canal is built on liquifiable sand, which makes it far riskier.
He'll write up his report later this week and the state engineer will decide what to do about it.
