The state of our nation’s dams and bridges is concerning. The USA is home to 84,000 dams. A handful of these dams produce power for millions of homes.
Bridges number an outstanding 614,387 in the USA with 40% of them more than 50 years old. The cost of just rehabilitating the backlog of structurally deficient bridges in America is estimated at a jaw-dropping $123 billion.
That number is growing every day and is a clear indicator that major infrastructure in America has not been maintained and the problem is going to get worse and cause more harm the longer we let things deteriorate. Finding the money and justifying the cost of replacing or upgrading something that still appears usable, is going to be difficult in many ways.
Concrete is not as permanent and strong as people tend to think
Concrete has long been one of the best building materials in terms of strength, cost, and ability to stand the test of time. Unfortunately, even the strongest and most well made concrete structures all suffer from a more limited life than what people realize. Concrete is not permanent and does not last forever.
The Problem with concrete dams
While actual concrete is tough, the method of reinforcement is not. Metal rebar and sheets were and still are used to create a framework to support concrete and keep it from cracking, splitting, etc. While the concrete itself may be strong, the metal framework within eventually rusts out. As the rusting increases the strength of your concrete decreases and eventually fails.
In the 1930s part of the New Deal to get America working again involved a lot of infrastructure projects such as the TVA dams in East Tennessee and North Carolina.
A lot of the bridges throughout the country are very old and some have had very little maintenance or upgrades over the years. Consider that in the 30s there was nowhere near the amount of traffic the nation’s roads must deal with today. While we may think of cars being very large, the reality is that more people drive large vehicles now. Semi trucks were not around and box trucks were limited. Deliveries took place but not with the frequency that is required now.
Bridges that were designed to have a few regular size cars on them at a time are barely big enough for two to pass each other now. Matt and I live in a rural area outside a small town and many of the paved back roads were clearly intended for smaller cars and trucks and were never expanded in size. Crossing a bridge with another vehicle requires great care, especially in the day and age of texting drivers.
Some dams that are made of concrete that is near the end of its structural strength are very large which means a failure could impact a lot of people.
My concern is always that due to cost, those in charge will wait until something truly bad happens as they did with the Oroville Dam in California. For many years it was known that the dam had issues.
Actually, that incident would not seem that serious compared to what could occur with The adage “if it ain’t broke, don’t fix it”, can lead to devastation when you are talking about large pieces of national infrastructure.
A lot of dams were created for power generation too so if there is an issue, the grid could be affected. The TVA Dam system, for example, was the reason so much of the South had a way to get electricity in the 30s and 40s. Plenty of people lived with oil lamps until that time.
Dam failure in Nebraska
The Spencer Dam failed recently in Nebraska causing massive damage and destroying the highway. The dam is a mix of concrete and earth construction. I found it interesting that there may be a court case to address if the dam was properly maintained. A recent article in the Omaha World-Herald featured a retired Army Corp of Engineers inspector stating that the dam is mostly earthen and earthen dams are only meant to last 60-70 years without extra reinforcement.
His words are very concerning considering how old the dams of America are.
Metal reinforcements in concrete that is exposed to moisture all the time will rust out, eventually
Concrete is porous so any moisture that is near it will get absorbed into it somewhat. With a dam, a lot of the concrete is always in contact with water. The metal reinforcements would theoretically have an even shorter lifespan than concrete that is just structural and not constantly soaked.
Some major concrete dams in America
The Hoover Dam
This is the most productive hydroelectric dam in the United States. It was built from 1931 to 36. It is an amazing 660 feet thick at the base which is good because it is holding back a lot of water. At 726 ft high and 1,244 ft long, this is a huge dam. Of course, it is made of concrete that is approaching 90 years old. While the base of the dam is thick, it gets narrower towards the top. Any structural failure is a big deal. It is the largest man-made reservoir in the USA and while it is built with a special concrete aggregate that is supposed to resist an alkali-silica reaction that causes swelling and cracks; the reinforcements are still metal and prone to degradation over time. Let’s hope that the sheer volume and thickness of the concrete is enough to hold for a lot longer. Regardless, the older a dam becomes the more likely it is that it is going to have some issues.
The Grand Coulee Dam
This dam on the Columbia River is part of the largest power producer in the United States. This dam was built over a longer time frame, from 1933 to 1942. It is no wonder it took so long to build since it is an amazing 550 feet in height and nearly a mile long. That is a flabbergasting amount of concrete and work. The Columbia is a huge river that is hard to image unless you have seen some of the other Top 10 largest rivers in the country. The dam and surrounding power plants produce enough power to run 2.3 million homes for an entire year.
Earthen dam dangers
While concrete dams have their issues, it is amazing just how many extremely large earthen dams are in America. Earthen dams are basically just rock and dirt that is piled up. These dams can be challenging to build but they don’t require a bunch of concrete or metal.
In Western North Carolina we have a few very large earthen and stone dams. Matt and I sometimes go fishing near a few of them because of the stocked trout.
Earthen dams are very susceptible to seismic activity. A tremor in the earth can cause trouble. Since there is no major framework, just rock, dirt, clay, etc, it can be easy for openings to occur. Of course, over time the likelihood becomes greater.
The Fort Peck Dam
One of the more alarming dams in the country is located in Glasgow, Montana. The 21,000 ft long and 250 ft tall earthen dam holds back the Missouri River. Some people are very concerned about how susceptible such a large dam is to the movement of the earth.
One might assume only those in Montana have something to worry about if there is an issue with the dam but the truth is that if the dam ever goes, it could wipe out another 5 dams downriver, many of them earthen as well. Residents of St. Louis, Missouri would be right in the path of a lot of water.
The Fort Peck Dam is a hydraulic fill dam. To build the damn a slurry of mud and water was pumped upstream and downstream. During construction in 1938, the in progress dam failed and killed 8 people with another 127 swept away. Despite this set back, construction was resumed and now we have the 21,000 ft long dam of today.
Dams are no longer made the way the Fort Peck Dam is because it is not a strong method. After hydraulic dams failed in California in the 1970s, the government stopped using the method for any dam projects.
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The Mississippi River Control Structure
There is no question that the system that holds back the Mississippi River is impressive but it is also very old and showing signs of stress. It takes a lot to hold back such a strong and large river. The Army Corps of Engineers spent $1 billion to build this monumental system to keep the Mississippi from changing courses. Rivers naturally change course at various time periods but in the modern age, there are a lot of people and a ton of infrastructure that would be displaced if the river was allowed to change whenever nature wanted it to. Water follows the path of least resistance and the Mississippi wants to choose a path that is steeper and provides a shorter path to the Gulf of Mexico.
So far this structure has done its job but a huge amount of water due to rains or flooding upstream could change that. There is also the danger of the structure failing during a controlled release of water. A small scale failure on the low sill structure occurred in 1973 and almost led to a total failure of the Old River Control Structure. The hydroelectric plant was added in the 1980s and produces 192 megawatts of power. That would be a huge amount of power generation to lose in the event of a catastrophic failure.
The bridges in our country were often made in a time when vehicles were much smaller and less heavy. The bridge that crosses the creek near where we live is not really made for the heavy equipment that sometimes goes over it and it can only accommodate a single car at a time. There are plans to replace it and widen the road some but we have not heard from the surveyors or seen any work done on it and they were supposed to have been done almost two years ago. We know that surveys and aerial work were done but there has been no sign that the needed replacement is anywhere on their priority list.
I used to have dreams as a child that the bridge between Mount Vernon, Washington and Burlington would fall into the Skagit one day and worst of all I would be walking across it or in a car with a relative. Well, I grew up and moved away and one day I woke up and part of the sister bridge that was a ¼ mile down the river and on the I-5 interstate, dropped into the water. Luckily no one was killed, but I had friends that had driven on the very bridge very close to the time it happened. I was so relieved they were okay and horrified that my nightmare had actually happened to some people. There are very strong currents and undertows in the Skagit and a lot of small whirlpools. It is not a river that people just go swimming in the main branch of.
It can be hard to upgrade a bridge that is old and not meant to handle wide vehicles and heavy loads. A lot of the time the bridge has to be replaced entirely and even if the money is there the planning, rules, and scheduling, as well as prioritizing which get replaced first, can all mean that things are ignored until something terrible happens and the outrage grows.
We have been ignoring our maintenance and spending money on other things
Infrastructure is very important, but it is very easy to ignore the maintenance and get in the mindset that what the previous generations created is still solid enough to make it through the next generation and all that modern life can throw at it.
It case you haven’t noticed, money is actually not as plentiful as some would like to think.
A lot of cars pass over busy bridges each day.
In the past, the population density and sheer amount of people in a region or traveling to it was much more limited. Yes, people used to make more road trips, but the population was just so much lower in some areas. Where I live now had very few houses a generation ago and now they are dotted in many of the areas that used to be nothing but cow pasture and woods. Consider that a lot of people that live in small towns and suburbs have multiple cars too. In the past, a family had a single car that was shared or just used for one person to go to work.
People carpooled more in the past than they do now too. There are plenty of homes in America that have 2-4 cars and drivers in them. All it takes is a mom and dad both working and two teens over 16 and you can see how it is easy to have at least 3 cars. Now consider that all that traffic is on roads that were originally intended for less traffic and use. Sure they may have been repaved but many of the bridges have had the bare minimum done to keep them maintained. Any supports become weaker over time if measures are not taken to reinforce.
So what can the average person do?
Thinking about this problem is one of the times when I found it easy to feel a little bit helpless. Regardless I got over this and come up with the following things to consider.
Consider the bridges and dams in your area and when they were built.
Some bridges are much more up to date than others. If you have a newer bridge or dam near you, then you are probably okay. The bridges and dams built during the early 1940s and before are the ones that have the greatest likelihood of being in a weakened and ignored state. If some have been upgraded then that is great and to your benefit.
During a long emergency, pay more attention to the state of bridges.
Even if major replacement and repairs have been ignored, at least things like paving and graveling have occurred on bridges. If there is an SHTF situation, then the fact is that a lot of things are going to be more ignored than they ever were. If you have a bridge, you use often it is not a bad idea to look for any major signs of distress.
There is not a lot of us can do about the state of dams. It is pretty clear to me at least that things like this are ignored for the most part until they cause a major problem.
I am really attached to where I live and could not imagine moving and starting over. With 1600 grape vines, a house we built, and all the work, it would be extremely difficult to start over elsewhere.
If you are looking for land or a home to set down roots, then you should consider if there are any dams near you that are large enough to cause you real trouble if they fail. If a failure occurred would it even be possible for you to have a warning? Would just a small portion of your property flood or would your home be ruined beyond repair or swept away?
For those that already live beneath a dam the only advice I can offer is to try to figure out how much time you have to get out if any and if you have a window, make sure to have a good go bag for everyone in your family and keep the car topped off with gas so you can make a quick exit.
If you are very concerned or know for a fact that a dam above you has structural issues that are not being addressed, you might consider moving. That sounds extreme and I cannot tell you what level of risk is best for you, but you do need to consider if you are ok with the risk over the years.
Part of the reason my Dad and I left Washington State and the North Cascades is that even back in the 90s, the number of potential disasters was a little much. With a river that seemed to cause floods more than in the past, active volcanoes, and a ton of dams that had cracks even then, it just didn’t seem safe. The massive drug issue and lack of opportunity were other factors.
Bringing the issue up with government entities
While I wish I could say that I have faith that those in charge will listen to infrastructure concerns, I do not think many people will be able to accomplish much towards convincing a government official that something needs to be fixed before it causes a major issue. It is sad that death, injury, and damage to land is often what it takes to bring attention and funding to big pieces of infrastructure.
If you choose to bring up concerns over bridges or dams, make sure to do a lot of research so you can make a good argument for your case. Numbers matter so if, for example, people on your street have been noticing anything alarming about a bridge, the more people that voice their opinion about it the more likely it is that concerns will be taken seriously.
Consider different ways of getting home
With infrastructure crumbling, it is a good idea to know a few different routes to get home via automobile and on food. During a long emergency, you may want to avoid bridges that have been let go. Also, if bridges are a place that thieves and others think people are going to cross every day, it can be easy to be targeted. Bridges can become very damaged by explosives during times of severe unrest. A bridge that has received a lot of firepower should be approached with caution as the entire support structure may be far more weakened than you might think.
Consider now how you would get home if the main bridge was not available.
There are many areas where you may have to go 10 miles to cross a body of water so an alternative route is not feasible for some unless the situation is very dire. When we lived on the Skagit River in Washington, the bridges to get on the other side of the river were 10 miles apart and that was not on an interstate either. This could mean adding 20 minutes or more to a drive time depending on how far someone has to go back once they cross. You may know alternative routes already but if you do not, then now is the time to get out the GPS, map, or look on Google and plan out the best way to get home if your bridge is out or unsafe to use. Make a note of how much longer these routes will take. It is better to be safe and take a little more time than to get hurt or injured during a long emergency.
Do you live near a dam or rely on a bridge to get home? How much do you know about the dams and bridges around you? Have you tried to bring up the subject of dam or bridge maintenance with government officials?