Monday, February 13, 2017

Oroville Dam Spillway Disaster

Oroville Dam Spillway, when I was young.
Ronald Reagan, governor of California at the time set the stage for the dedication of the Oroville Dam, which was completed in 1968, construction began in 1961 and was ahead of scheduled by a year!  An outstanding achievement constructing an Embankment type dam making her the tallest dam in the U.S.

Today the news is flooded with reports of the failure of the spillway and the emergency overflow which had never been used since she was constructed.  Let's look at something for many are pointing a finger of who to blame for this disaster.  In retrospect to creation, the Earth was created in 6 days, on the 7th day the creator rested.  On the 8th day, he got complainants.  On the 9th day, he created maintenance!  I created this theory for I've been involved in field service and preventive maintenance is a must.  But like anything the customer holds off because of budget restraints.

Oroville Dam Spillway running with damage.
From Wikipedia: Spillway Cracking and Investigation

In 2006, a senior civil engineer sent a memo to his managers stating, "“The emergency spillway meets FERC’s engineering guidelines for an emergency spillway,” and that “The guidelines specify that during a rare flood event, it is acceptable for the emergency spillway to sustain significant damage." The spillway cracked in 2013. A Senior Civil Engineer with the Department of Water Resources was interviewed by the Sacramento Bee and explained, “It’s common for spillways to develop a void because of the drainage systems under them” and “There were some patches needed and so we made repairs and everything checked out.” In July 2015, the state Division of Safety of Dams inspected the dam visually "from some distance." (end Wikipedia)

Resent photo taking today 2/13/17 showing erosion damage.
The construction of anything man builds will at some point fail and with the material used at the time for the spillway were steel rebar and concrete, which we use in our roads, bridges, building and dams.  Concrete will have a structural strength for 50 to 100 years but the main threat is the corrosion of steel rebar which expands and cracks the concrete.  The use of embedded materials in concrete is a real science and today for future construction for our deteriorating infrastructure we'll be better off using composites.  Plus from the looks of this collapse in the spillway, you can be sure water erosion was getting under this slab until a sinkhole was formed and the weight of the concrete having no support failed.  Water is a hell of a force!

Oroville Dam 2014 drought.
So if you want to blame someone for this failure it would be budget restraints that hold all of us back and all the outcomes from not digging deep into a budget ends up costing much more, unfortunately.  For there is always a time where maintenance can be performed, like the photo above.

Oroville Dam or do you say Damn!

Oroville Dam emergency overflow!
The Oroville Dam is not out of the woods yet, I understand the water has stopped flowing over the emergency overflow, good news.  But more weather coming this week and snow will be melting from the Coast Ranges, Klamath mountains and Cascade Rang. There is not much time for solid repairs, fill that failed spillway with boulders that can withstand the full force of water at CFS (cubic feet a second) coming down that spillway and piled just high enough that will launch the water over onto the remaining slab to lessen the damage to the leading edge... Mud-jack Hydraulic Cement forward and back under the damaged slab, you can also do this procedure if you have leakage with the emergency overflow, drill and fill!  Yeah, I know it cost more the application is used for underwater where water is flowing under consent pressure and Oroville Dam needs to avoid the ultimate fail! $$  

GOD'S Speed!

Damage Update

Major erosion on underline of emergency overflow.
The crew is going to be working frantically on the emergency overflow section because of severe erosion!  This section of the dam needed to be paved like the spillway down to the riverbed.  The underline structure of the Emergency Overflow is at risk!  The volume of water flow on the main spillway was increased or all hell was going to break lose!  At this point, many are going to be without a job!  Major neglect, this site was never completed, now you're between a rock and a hard place.  Way?  Skimmed the budget and slacked off maintenance on the main spillway!


Main Spillway after Heavy Rains

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