Do you live downstream from a compromised Dam? Dam Failures in the United States, how common are they?

  17% of the 90,580 Dams in the United States are classified as either a high or significant risk of catastrophic failure. Occurring without warning a dam failure caused by an intense rainfall is able to produce a flash flood in a matter of minutes. Other causes are easier to predict such as seasonal melting snow, and the spring thaws in the North channeling the water south down the Mississippi river valley and many others.

Every Spring on the Mississippi this happens, as well as all of
the contributors upstream, Missouri, the Ohio and many
smaller ones.

  What factors can cause a Dam Failure?
 * Long periods of rainfall, especially after a prolonged drought, the reservoirs are lowered allowing the banks to dry out. The water from the rain begins to fill the reservoir washing debris from the banks into the water allowing it to float aimlessly. That is until the level reaches a level that the water rises to such a level that release is needed. When the spillways are opened and the water begins to flow the debris that was washed into the water begins to flow towards the Dam. This debris, logs, trees, weeds, docks and even boats are drawn to the spillway eventually causing a "clog" and more problems with drawing the lake down.
 * Spillways that are not designed properly or the reservoir capacity was increased without the spillway being enlarged. As the water rises the spillway if unable to handle the increased flow of water is "overtopped", the level of the lake is excessively over the top of the spillway. When this occurs the water being released is not able to be controlled as successfully as a more moderate level, the added flow may cause erosion and destruction of compromised areas of the spillway.
 * The foundation of the Dam may be eroded, Dams do leak on occasion, most leaks are harmless but when they course their way under the structure into the very material that stabilizes the Dam, it may be compromised.
 * Poor maintenance is a cause, trees must be removed, seepage through the Dam is not repaired, and poor maintenance of valves, gates, and grates may all add up to a Dam failure.
 * Improper material are used during construction, most of the Dams are 50 years or older, construction techniques have improved over the years, making inspections critical. The improper design has contributed to at least one failure in the U.S. June 5, 1976, the Teton Dam failed when the water it was holding back, escaped around one end of the Dam causing the foundation on the side to wash away. The failure caused the deaths of 11 people, 13,000 head of cattle, and damage which has been estimated at $2 billion.
 * A Dam upstream fails to add another full reservoir to an already full one, many times Dams are built on the same waterways upstream from one another. Some of the upstream dams are much smaller and weaker, many earthen and some much older than 50 years old. When a Dam reaches that age it is considered past its life, something needs to be done with it.
 * Events that cause overtopping, landslides are a good example, the side of a reservoir may collapse causing the level of the lake to rise dramatically. Hurrican Katrina is another good example, huge amounts of rain inundated New Orleans causing the levees to be overcome by the rising floodwater. Levees are a type of Dam as well.
 * High winds can cause "storm surges" causing high waves to overtop the spillways, sometimes even topping the Dam itself.
 * Terrorism, Earthquakes, or other high energy events able to cause longitudinal cracks in the structure or the banks on the side of the Dams which may lead to failure. (Link to the State of Wisconsin's Dam safety fact sheet)

 Dam Failure is a very unlikely catastrophe, however when they do happen the results are dramatic, leading to the cause of multiple deaths, extreme infrastructure failures, and the shutdown of essential facilities that may last for years. Generally, at a minimum 50% of affected structures sustain severe damage.
 Dam Failure does occur, however, of the approximate 90,000 Dams in the U.S. 33 failures have occurred between the years 1918-1958, causing 1,680 human deaths. 9 Dams failed between 1959-1965. In the year 1889, 2,209 people died when the South Fork Dam failed upstream from Johnstown, Pennsylvania. In 1928 The St. Francis Dam failed to cause the demise of 500 humans. During the decade of the 1970's  the Buffalo Creek, Teton and Toccoa Creek failures caused over $1 billion in damages and cost all totaled 175 lives. Since the Federal Government enacted laws which make inspections mandatory adhering to strict safety guidelines failures have been dramatically reduced.

The Teton Dam Failure, it's very dramatic, I bet it was loud.

  One of the problems with Dam maintenance is that inspections can detect only so much if a flaw is hidden deep in the structure the chances of it being seen is not possible. That raises the reality of not knowing the flaws until the structure is placed under stress, an actual "dynamic" test, most of the time the Dam is OK. Sometimes, however, the structure fails and a massive evacuation is ordered, of which happened February 2017 at Oroville, California when the spillway faults were exposed after water was released down the overflow.
 What can we do if we live in an area affected by the flood zone of a possible Dam failure or major structural failure?
Here are a few pro-active preparatory actions.  
 * Know your risks, find out if the Dam you live downstream of is "high" or "significant" potential hazard. That information may be obtained from your state or county emergency management agency, at the National Inventory of Dams or inquire with the Association of State Dam Safety Officials.
 * The states or federal governments don't own all of the dams, some are owned by local water companies, flood control districts and some by large corporate farms. Find out who owns the Dam you live downstream of, find out if the inspections have been carried out and the remedial items resolved, in other words just be curious.
 * Find out if the owner has an Emergency Action Plan drawn up and if it is available for the Dam if so get a copy. It will help you to build a plan of your own, in it, you will find instructions specifying preplanned steps to take to eliminate or lessen property damage and loss of life. It will spell out what to do if you have to evacuate.
 * Plan your own escape, write up an evacuation plan, it can be included in your general emergency plan, as a separate section or a stand-alone document. It is easier to keep track of one document, especially in light of the fact that each member of the household will have a copy of it, we want to make it as inclusive, informative, accurate and convenient as possible. Make sure to have supplies on hand to be certain you and your group each have food and water for at least 3 days, that's the 72-hour kit. It is, however, best to have enough supplies to maintain yourself for at least one week, a minimum of 1/2 gallon of water per person is required. In my case, I must have some sort of coffee and a way to make it hot in my bag.  Never use floodwater for any purpose. (Link to FEMA's page with everything we need to formulate an escape plan)
  Be certain to include every member in the writing of your plan, I have read accounts of parents not including the children, the kids had no clue there even was a plan. That's a huge mistake, they must have buy-in, all of them, they will take ownership of the suggestions they made and run with them. The kids will be determined to show you that their ideas will work, and they will.
  Take care of the pets, in advance, find out the best you are able if your assigned evacuation post and relief center will support pets, if not a solution must be established. Don't release your pets to make it on their own, most can't and won't survive no matter how resourceful we may think they are. Link to a dogs and cats emergency kit.

The New Melones Dam, it's a good solid Dam. 

  I live downstream from the Oroville Dam, I have lived downstream from Dams every place I have lived in California. I have watched work being done on some Dams when the reservoir has been drained, I worked on the New Melones Dam in the 1980's. I also worked on the Wishon/Courtright tunnel project. What I learned from working on them is that every one of us had one thing in common, we were all human and capable of mistakes. The New Melones Dam had an engineering problem of the simplest sort, we built the trash grate from the wrong material, Stainless Steel was specified, we used Galvanized Steel, the difference is about 100 years in the expected lifespan. We also encountered engineering mistakes while building the Diablo Canyon Nuclear plant and Crows Landing in Texas. I bring this up because mistakes are made, we're human, mistakes prove we are.
 Thanks for reading and sharing, leave a comment or story and tell me what you've done to prepare for a Dam Failure. Thank you.
jacquesandkate emergencykitsplus.com