What is infrastructure? Infrastructure is the essential, physical organizing framework meant to facilitate the smooth, day-to-day operation of society. It includes transit, waterworks, sewers and waste disposal, communications, the physical layout of the community and more. It is both a facilitator in helping the society function but also, often unintentionally, serves to limit and misdirect the manner of that operation and, most importantly, development and growth. The defensive walls constructed around the cities of Europe proved very valuable in protecting those cities from attack by enemies wielding swords and spears but they have also imposed frustrating limitations on the growth and development of those cities in modern times.
The American automobile industry, in order to improve its sales and profitability, bought up and shut down long-established and efficient public transit systems across the nation. They succeeded in having the interstate highway systems implemented, setting the nation on the road to being dominated by suburbs, of course devoid of public transit. They killed the city centre and left it to rot as retail rushed out to the suburbs where the customers now lived.
Many communities, trying to overcome the domination of the automobile, are finding that the needed added investment in effective public transit, and the infrastructure to support it, is generally greater than the public coffers can handle, definitely greater than the car-culture taxpayers are willing to support, that they are stuck with the private automobile being the driving force behind infrastructure choices. In my youth a saw the implementation of public water and sewer systems in my hometown, an expensive proposition that required years of special tax levies to pay and disrupted traffic and commerce in the town for years. The benefits were great enough - did you ever have to use an outhouse during a cold snap in the middle of February? - that the taxpayers were willing to absorb the special tax levies.
Man is not the only species that builds communal infrastructure. Among the others which do are; ants, termites, bees, beavers, groundhogs, prairie dogs, rabbits, and corral. Other species, however, do so instinctively. Man does so by intellectual choice. If anything, our instincts which were formed as early primates would mitigate against our creation of infrastructure. In fact, man is the only primate that does create infrastructure. This suggests that our tendency to create infrastructure was not a slow, evolutionary development but grew out of our developed methods of seeking security in numbers, of banding together and forming tribes.
Infrastructure and organized society have gone hand in hand from the beginning. It is critical in both modern and less developed societies. The infrastructure involved may be very, very different but equally critical. Infrastructure was critical to Greek society, the Romans (the Romans had a consistent town plan that they used in the development of most of their communities), the Aztecs and Mayans, and all other organized societies through history.
The one very important factor they all have in common is without constant maintenance the infrastructure soon begins to break down. And the society begins to break down with it. As it deteriorates the infrastructure that was critical in building the society becomes a dangerous liability. The critical dependence of society on its infrastructure was strongly highlighted in a report "Cumbria flooding exposes UK’s vulnerability to infrastructure failure". The report claims, "We are often only hours away from social collapse if our critical infrastructure were to fail totally.... The failure of a single piece of infrastructure, such as a bridge, not only causes difficulties in reaching basic commodities and services, but also leads to the failure of other connected infrastructure networks such as electricity, gas, telephone lines, waste and water supply."
All components of our infrastructure have a designed life span, either implied or explicit. Bridges and dams, for example, are generally designed for a life span of fifty years. Many commercial buildings may have a designed lifespan of thirty years or less. To achieve the designed life span, of course, the designer and builder of the infrastructure assume it will be properly maintained according to the instructions supplied. A large petrochemical plant I was involved in as a systems analyst, for example, had a large "chart room" where the thousands of drawings, blueprints and maintenance manuals and logs for the plant and all of its components were kept, maintained and constantly referenced by maintenance staff and engineers.
Designed life span is all too often viewed, by those assuming responsibility for it, to be somewhat like many view the "best before" label on the food they buy, a guideline, a ploy to sell more product. They will take their chances and keep their fingers crossed. Many dams and bridges with a designed life span of fifty years are still heavily in use a hundred years and more after construction, many without appropriate and needed levels of maintenance. Many bridges built for an anticipated traffic load of "x" are still in operation after twice their designed life span with traffic loads of 3-4 or even 10 times more than the design criteria. Many large dams still operating more than a hundred years after construction have lost over half of their reservoir capacity from silting and are in constant danger of over-topping during a heavy rainfall or from erosion-induced land and mud slides. Many community water and sewer systems are well over a hundred years old, some more than two hundred years old, with an annual burden of water main breaks running into the hundreds, some in the thousands (Toronto has an estimated 11,000 water main breaks a year). In most of these communities the extensive suburban development around those communities is being connected to the same antiquated water and sewer systems placing tremendous added load pressures on those systems every year and burdening those suburbs with a water and sewer system already past its designed life span when they connect to it.
Infrastructure maintenance requires, of course, an army of specially-trained maintenance staff and an abundance of specialized equipment and facilities. In most cases, however, maintenance is short-changed, most often due to politically-imposed budget constraints. According to the report "Infrastructure Failure in America", "America's infrastructure is aging.... Now, with ever rising costs and reduced funding/taxes for public projects, compromises and trade-offs are made and only the things in worst shape are attended to. Evidence of this is all over the place - power grid problems and blackouts, the bridge collapse in Minneapolis, the steam pipe explosion in New York, the levee breach in New Orleans. Unfortunately the blame falls on the agency responsible for infrastructure upkeep. Very rarely are the fingers pointed in the direction of politicians or government officials who make the money decisions and choose what gets funded." This is further highlighted in the report "Metropolitan Infrastructure Sustainability Study". This study found that "Funding emerged as the number one issue facing cities today. When asked to name their most serious infrastructure challenge, without prompting, three in five cities (59%*) said obtaining infrastructure funding was a key challenge. Some 42 percent* said funding gaps were creating challenges for maintaining or improving aging infrastructure. Cities are more likely to name funding for maintenance or retro-fitting of existing infrastructure, rather than funding for new infrastructure, as a critical challenge." Another report, "Infrastructure Investment Deficit" points out that "Recent research from various associations in Canada shows that there is a growing infrastructure investment deficit occurring in many sectors. This results in deteriorating infrastructure and escalating costs since the longer roads and buildings remain in a state of disrepair, the higher the costs to refurbish or replace."
This tendency to defer infrastructure maintenance is done under the assumption that the deficit can be made up later, and the hope that there will not be a disastrous infrastructure failure before then. But with peak oil fast approaching - or already here depending on which model you adhere to - this assumption that deferred maintenance can be caught up is very likely to result in a string of those disastrous failures that infrastructure and maintenance managers have for years been hoping against.
And yet even today massive investments continue to be made in new and upgraded infrastructure designed for operation in and dependent on a high-energy, high-tech world. A quick check of Google for "infrastructure investment" will net you literally millions of articles on projects for new and upgraded infrastructure.
But what if those choices were no longer available? What if the cost of maintenance and replacement mushrooms to 10-20 or more times current levels? What if the materials and parts needed to undertake that maintenance are no longer available? What if the specialized equipment and the transport to get equipment and maintenance personnel to the problem are no longer available? What if the heavy equipment to dig, build, move is no longer available? What if all of the fuel and energy to power all of that equipment is no longer available? This will be increasingly the case as we move deeper into the post peak era.
These are the true costs of peak oil. It's not about the cost of gasoline for the family car, not being to afford that driving vacation to Florida, the rising costs of food and other goods because of increasing transportation fuel costs. Those will be, or already are, the first warning signs that peak oil is upon us. But increasing costs will soon give way to scarcity and the depth of that scarcity will increase a little more each year. At first many poor nations will be priced out of the hydrocarbon fuel market. Soon, however, any level of government without the right to print money, even in rich countries, will start to wrestle with a growing disparity between income, which is primarily from taxation, and costs. Many of the American states, in fact, and many more communities, are already struggling hopelessly to balance their budgets. They soldier on, like the funding-deprived infrastructure maintenance staffs, in the belief that the deficit will be made up "when things return to normal." They fail to recognize the current situation as the new normal, the only slightly painful edge to a new reality that will not be corrected..... ever.
Showing posts with label failing infrastructure. Show all posts
Showing posts with label failing infrastructure. Show all posts
Sunday, March 14, 2010
Wednesday, October 31, 2007
Cascade Failure in River Systems with Multiple Dams
It is time once again to speak of dams and things. It is not that I'm becoming paranoid about dams. At least I don't think I am. It is simply that the more I see and read and hear the more I believe dams, and their other attendant water control/management infrastructure, to be perhaps the greatest infrastructure risk for society during the long, painful implosion of the global economy, and our individual national economies, that will follow peak oil. It is not the greatest overall risk, of course.
The greatest risk to our bloated human population will be the collapse of our industrialized agriculture system and our inability to produce and distribute sufficient food for our global numbers, especially with the collapse of the global distribution system with the steady decline of oil and natural gas availability, on which modern agriculture and food processing are critically dependant. Death by starvation is a slow, tortuous process, taking the young, the old and the ill first. But the collapse of a large dam, or a series of dams of various sizes in a common watershed in a cascade failure, represents a sudden and inescapable catastrophe for all of those in harm's way downstream from the collapse.
There are over 45,000 large dams (defined as having a height of more than 15 metres (48.75 feet), or above 5 metres holding a reservoir volume of more than 3 million cubic metres (87.75 million cubic feet)) around the world[6]. The majority of these are, you may be surprised to learn, in developing or underdeveloped nations. Although new dam starts have slowed in the past decade, according to the report 17 Large Dams Under Construction by Basin - Watersheds of the World, "As of 1998, there were 349 dams over 60 meters high under construction (IJHD 1998). The countries with the largest number of dams under construction were Turkey, China, Japan, Iraq, Iran, Greece, Romania, and Spain, as well as the Paraná basin in South America. The river basins with the most, large dams under construction were the Yangtze in China, with 38 dams under construction, the Tigris and Euphrates with 19, and the Danube with 11."[7]
Virtually every large river system in the world has numerous dams on both the main course and the various tributaries flowing into it. Even the mighty Amazon, viewed by most as one of the world's last, great unspoiled rivers, will soon have dozens of dams throughout it's watershed. The Brazilian government plans to build 31 new dams in the Amazon region by 2010. The largest of Brazil's planned hydro projects will "convert the Tocantins River into a series of lakes and hydro-electric dams, stretching for 1,200 miles and consisting of eight large dams and 19 smaller ones."[8]
The greatest risk is not simply that these large rivers have dams. It is the fact that they have multiple dams, most numbering in the dozens. There is great risk of a catastrophic cascade failure initiated by the collapse of a single upstream dam. Like a chain, a multi-dam water management system is as strong as its weakest link. And when that weakest dam is far upstream - which it usually is, generally in a remote and sparsely populated area, far from critical eyes - the downstream risk is magnified.
This is not an unprecedented risk, or even an unusual risk. Cascade failures have happened on numerous occasions over the last couple of centuries. The greatest was perhaps the collapse of the Henan Province dams in China in 1975. "As many as 230,000 people died in this domino-effect collapse of dams on the Huai River, some 85,000 in the flood waves and the rest from resulting epidemics and famine. The disaster began with the failure of the large Banqiao Dam in a typhoon, which resulted in the collapse of as many as 62 dams downstream."[6] The flood that was released in the collapse "created a wall of water 6 meters high and 12 kilometers wide ..... moving wall of water was 600 million cubic meters of more water." "The flood spread over more than a million hectares of farm land throughout 29 counties and municipalities."[9]
Consider the numbers. If a river system, like that above, has fifty, sixty or more dams on it, and each of those is, on average, holding back just the minimum large dam reservoir volume of three million cubic meters of water (the Banqiao Dam alone was designed to hold 492 million cubic meters), that entire system is holding back an amount of water equivalent to 3-million cubic meters times the number of dams. Fifty dams, one-hundred-fifty million cubic meters. In a cascade failure such as this, a person or community downstream is not at risk of inundation by the 3 million cubic meters in the dam nearest upriver from them. They are at risk from a cascade failure starting far upstream releasing a massive torrent of one-hundred-fifty million cubic meters of water. If that person/community is downstream from the dam lowest on the river - large population centres are more common at a river's mouth than along its course - that whole mass of water will come at them all at the same time in a wave that could be hundreds of feet high. Every dam downstream from the initial collapse, remember, has a design capacity of only 3-million cubic meters. It has a wave of water coming at it of 3-million cubic meters times the number of upstream dams already collapsed.
Of course, it is not just the massive volume of water behind a dam that rushes downstream as a dam collapses. The catchment area behind every dam gradually has an accumulated build-up of silt and debris. Over time any dam will completely silt-up. Some accumulate silt faster than others, largely a factor of geology and human activity upstream such as farming, lumbering and mining. When a dam collapses all of this silt and debris is also released. In addition the massive rush of water and debris scours the river banks and downstream river bottom and picks up even more debris as it progresses downstream. In floods it is usually the debris, not the water, that does the most damage. Flood water can carry boulders weighing many tons along as though they were pebbles.
Dams are not designed to withstand the pressures or the speed from the sudden influx of millions of cubic meters of water and debris such as this. They are designed to handle the build-up of water following heavy rainfall, or with the spring snowmelt, or the occasional collapse of a small bit of upstream river bank, or other normal events. As the report And The Walls Came Tumbling Down: Dam Safety Concerns Grow in Wake of Failures, Changing Climate says, "Building a totally safe dam is simply not possible. US dam-safety expert Robert Jansen says that dams “require defensive engineering, which means listing every imaginable force that might be imposed, examination of every possible set of circumstances, and incorporation of protective elements to cope with each and every condition.” This is clearly an unattainable target. In the real world, the degree of “defensive engineering” applied to the design of a dam will be decided by economics. ..... There will always therefore be pressure for dam builders to cut corners on safety."[6]
When a dam is designed to handle flood control (either alone or in conjunction with irrigation and/or hydro-electric generation) it must be designed with appropriate excess capacity (the Banqiao Dam was designed to accommodate 375 million cubic meters of flood storage)[8] and flood gates to handle the containment and controlled release of flood waters. "Flood gates are an expensive component of a dam's construction so engineers must consider a trade-off between the cost of the dam and the security it will provide. ..... The dam authorities must decide the proper excess capacity to maintain based on the trade-off they see between the value of stored water versus the value of flood control."[8]
There is another important component, as well, that has not been factored into the design of dams, most of which have been constructed in this past half century. Even dams currently being designed and built, however, share this shortcoming. That factor is global warming. As the above report notes, "Engineers design dams and their spillways to cope with the extreme floods that they predict using past records of streamflow and precipitation. It is vital that spillways are adequately sized – if a spillway is overwhelmed there is a high risk of a dam break. ..... But the assumption that we live in a stable climate no longer holds. Streamflow patterns are changing and are almost certain to continue to change, and at an accelerating rate, over the lifetime of the world’s dams. As noted in a World Commission on Dams’ background paper: “The major implications of climate change for dams and reservoirs are firstly that the future can no longer be assumed to be like the past, and secondly that the future is uncertain.”."[6]
As it looks at the moment, allowance for climate change is not likely to be built into the design of new dams anytime soon, let alone upgrading the existing dam inventory. There seems to be a large dose of denial amongst those involved in the dam designing/building industry. "While the climatic future is indeed filled with uncertainties, one trend upon which climatologists almost universally agree is that we will see (and indeed are already seeing) more extreme storms and increasingly severe floods. And yet, alarmingly, the vast majority of dam proponents and operators deny that climate change is even relevant for dam safety. The president of a major dam engineering firm told this author last year that climate change is "a problem for dams in 20 or 30 years, but not now."."[6] Even were that the case, that 20 to 30 years is exactly the time when the combined impact of global warming and oil depletion will severely hamper our ability and desire to upgrade dams to a safe level. Even to bring the world's dams up to levels currently considered safe that investment would be sizable. "But if securing US dams would cost $30 billion [some estimates, in fact, exceed $100 billion for U.S. dams] and the US has an estimated 10% of the world’s dams, a ballpark figure for the global under-investment in dam safety would be $300 billion."[6]
That state of denial also manifests itself at government levels, sometimes in the extreme. The most common and obvious form of this government denial, of course, is in insufficient budget allocations to maintain the dam inventory at safe levels. Following the catastrophic Henan Province cascade dam failure that killed an estimated 230,000 people in 1975, however, "The Chinese government kept the incident secret for about 20 years, but information on the disaster was eventually leaked to the outside world."[6] If this was possible, even in a closed totalitarian state, in an age of instant global communication, what might happen with those catastrophes in 20 to 30 years time in a very changed, power-reduced world?
Few countries have, or can even afford, comprehensive dam inspection/maintenance safety programs. Most, especially in underdeveloped countries, were built with inordinately expensive borrowed funds, monies which are not sufficient to cover future maintenance which may not be needed for 20-30 years after the dam's completion. "Despite the massive risk to human life and property posed by large dams, few countries have comprehensive dam safety legislation. Such laws should cover the engineering criteria that new dams must meet; the regular inspection and repair of old dams; and the preparation of emergency evacuation plans for people living downstream. ..... Studies in the US have shown that where early warning systems and evacuation plans are in place, the fatalities caused by dam bursts are on average reduced by a factor of more than 100. However, such plans have been made for only a handful of the world's dams, mostly in the US, Canada and Australia...."[6]
Even where safety legislation and programs exist, however, it generally treats dams on a one by one basis. Each dam is designed, built, inspected, maintained as though it were a structure in isolation. But most large river systems have, as noted earlier, multiple dams along their course. The excess capacity of any dam is designed to accommodate a particular volume of water from floods or other designed-for events. But they are designed assuming that all other conditions are normal and that the combined infrastructure of dams on the river will remain intact through the event (If I did not already know it instinctively, thirty years of system design experience would have taught me that you never design a system with the assumption it will work perfectly). In other words, a dam designed with a flood containment capacity of 300 million cubic meters assumes that that volume will be delivered by nature. The fact that there is a dam upstream with a capacity of 500 million cubic meters, or a series of dams with a total capacity of a billion cubic meters, is irrelevant in the design.
As we pass peak oil and the budgets and abilities to properly maintain our massive dam inventory diminish over time (time in which those dams continue to age and require increased, not decreased, maintenance) this design shortcoming will become critical for those water courses with multiple dams, which includes most of our large river systems. The risk to any dam on such systems is not the once-in-a-hundred-years or once-in-a-thousand-years flood that the dam is designed to accommodate but rather the combined capacity of all of the dams upstream from that dam plus the hundred-year or thousand-year flood. No one, especially those living along the banks of such river systems, should take any solace from the fact that such events may be twenty or thirty years in the future. That should, in fact, be more a cause for serious concern than solace. That future in which those failures increase in probability is a future of declining energy and infrastructure maintenance budgets and increased climatic extremes, a potentially deadly combination.
====================
Additional reading:
1) Fragmentation Of Riparian Floras In Rivers With Multiple Dams
2) Simulation of Dam Failures in Multidike Reservoirs Arranged in Cascade
3) NOTE: The following emails are reproduced in chronological order ...
4) Federal Guidelines for Dam Safety
5) Revised Criteria for Assigning Hazard Potential Ratings to BLM Dams
6) And The Walls Came Tumbling Down: Dam Safety Concerns Grow in Wake of Failures, Changing Climate
7) 17 Large Dams Under Construction by Basin - Watersheds of the World
8) The Amazon Rainforest
9) The Catastrophic Dam Failures in China in August 1975
The greatest risk to our bloated human population will be the collapse of our industrialized agriculture system and our inability to produce and distribute sufficient food for our global numbers, especially with the collapse of the global distribution system with the steady decline of oil and natural gas availability, on which modern agriculture and food processing are critically dependant. Death by starvation is a slow, tortuous process, taking the young, the old and the ill first. But the collapse of a large dam, or a series of dams of various sizes in a common watershed in a cascade failure, represents a sudden and inescapable catastrophe for all of those in harm's way downstream from the collapse.
There are over 45,000 large dams (defined as having a height of more than 15 metres (48.75 feet), or above 5 metres holding a reservoir volume of more than 3 million cubic metres (87.75 million cubic feet)) around the world[6]. The majority of these are, you may be surprised to learn, in developing or underdeveloped nations. Although new dam starts have slowed in the past decade, according to the report 17 Large Dams Under Construction by Basin - Watersheds of the World, "As of 1998, there were 349 dams over 60 meters high under construction (IJHD 1998). The countries with the largest number of dams under construction were Turkey, China, Japan, Iraq, Iran, Greece, Romania, and Spain, as well as the Paraná basin in South America. The river basins with the most, large dams under construction were the Yangtze in China, with 38 dams under construction, the Tigris and Euphrates with 19, and the Danube with 11."[7]
Virtually every large river system in the world has numerous dams on both the main course and the various tributaries flowing into it. Even the mighty Amazon, viewed by most as one of the world's last, great unspoiled rivers, will soon have dozens of dams throughout it's watershed. The Brazilian government plans to build 31 new dams in the Amazon region by 2010. The largest of Brazil's planned hydro projects will "convert the Tocantins River into a series of lakes and hydro-electric dams, stretching for 1,200 miles and consisting of eight large dams and 19 smaller ones."[8]
The greatest risk is not simply that these large rivers have dams. It is the fact that they have multiple dams, most numbering in the dozens. There is great risk of a catastrophic cascade failure initiated by the collapse of a single upstream dam. Like a chain, a multi-dam water management system is as strong as its weakest link. And when that weakest dam is far upstream - which it usually is, generally in a remote and sparsely populated area, far from critical eyes - the downstream risk is magnified.
This is not an unprecedented risk, or even an unusual risk. Cascade failures have happened on numerous occasions over the last couple of centuries. The greatest was perhaps the collapse of the Henan Province dams in China in 1975. "As many as 230,000 people died in this domino-effect collapse of dams on the Huai River, some 85,000 in the flood waves and the rest from resulting epidemics and famine. The disaster began with the failure of the large Banqiao Dam in a typhoon, which resulted in the collapse of as many as 62 dams downstream."[6] The flood that was released in the collapse "created a wall of water 6 meters high and 12 kilometers wide ..... moving wall of water was 600 million cubic meters of more water." "The flood spread over more than a million hectares of farm land throughout 29 counties and municipalities."[9]
Consider the numbers. If a river system, like that above, has fifty, sixty or more dams on it, and each of those is, on average, holding back just the minimum large dam reservoir volume of three million cubic meters of water (the Banqiao Dam alone was designed to hold 492 million cubic meters), that entire system is holding back an amount of water equivalent to 3-million cubic meters times the number of dams. Fifty dams, one-hundred-fifty million cubic meters. In a cascade failure such as this, a person or community downstream is not at risk of inundation by the 3 million cubic meters in the dam nearest upriver from them. They are at risk from a cascade failure starting far upstream releasing a massive torrent of one-hundred-fifty million cubic meters of water. If that person/community is downstream from the dam lowest on the river - large population centres are more common at a river's mouth than along its course - that whole mass of water will come at them all at the same time in a wave that could be hundreds of feet high. Every dam downstream from the initial collapse, remember, has a design capacity of only 3-million cubic meters. It has a wave of water coming at it of 3-million cubic meters times the number of upstream dams already collapsed.
Of course, it is not just the massive volume of water behind a dam that rushes downstream as a dam collapses. The catchment area behind every dam gradually has an accumulated build-up of silt and debris. Over time any dam will completely silt-up. Some accumulate silt faster than others, largely a factor of geology and human activity upstream such as farming, lumbering and mining. When a dam collapses all of this silt and debris is also released. In addition the massive rush of water and debris scours the river banks and downstream river bottom and picks up even more debris as it progresses downstream. In floods it is usually the debris, not the water, that does the most damage. Flood water can carry boulders weighing many tons along as though they were pebbles.
Dams are not designed to withstand the pressures or the speed from the sudden influx of millions of cubic meters of water and debris such as this. They are designed to handle the build-up of water following heavy rainfall, or with the spring snowmelt, or the occasional collapse of a small bit of upstream river bank, or other normal events. As the report And The Walls Came Tumbling Down: Dam Safety Concerns Grow in Wake of Failures, Changing Climate says, "Building a totally safe dam is simply not possible. US dam-safety expert Robert Jansen says that dams “require defensive engineering, which means listing every imaginable force that might be imposed, examination of every possible set of circumstances, and incorporation of protective elements to cope with each and every condition.” This is clearly an unattainable target. In the real world, the degree of “defensive engineering” applied to the design of a dam will be decided by economics. ..... There will always therefore be pressure for dam builders to cut corners on safety."[6]
When a dam is designed to handle flood control (either alone or in conjunction with irrigation and/or hydro-electric generation) it must be designed with appropriate excess capacity (the Banqiao Dam was designed to accommodate 375 million cubic meters of flood storage)[8] and flood gates to handle the containment and controlled release of flood waters. "Flood gates are an expensive component of a dam's construction so engineers must consider a trade-off between the cost of the dam and the security it will provide. ..... The dam authorities must decide the proper excess capacity to maintain based on the trade-off they see between the value of stored water versus the value of flood control."[8]
There is another important component, as well, that has not been factored into the design of dams, most of which have been constructed in this past half century. Even dams currently being designed and built, however, share this shortcoming. That factor is global warming. As the above report notes, "Engineers design dams and their spillways to cope with the extreme floods that they predict using past records of streamflow and precipitation. It is vital that spillways are adequately sized – if a spillway is overwhelmed there is a high risk of a dam break. ..... But the assumption that we live in a stable climate no longer holds. Streamflow patterns are changing and are almost certain to continue to change, and at an accelerating rate, over the lifetime of the world’s dams. As noted in a World Commission on Dams’ background paper: “The major implications of climate change for dams and reservoirs are firstly that the future can no longer be assumed to be like the past, and secondly that the future is uncertain.”."[6]
As it looks at the moment, allowance for climate change is not likely to be built into the design of new dams anytime soon, let alone upgrading the existing dam inventory. There seems to be a large dose of denial amongst those involved in the dam designing/building industry. "While the climatic future is indeed filled with uncertainties, one trend upon which climatologists almost universally agree is that we will see (and indeed are already seeing) more extreme storms and increasingly severe floods. And yet, alarmingly, the vast majority of dam proponents and operators deny that climate change is even relevant for dam safety. The president of a major dam engineering firm told this author last year that climate change is "a problem for dams in 20 or 30 years, but not now."."[6] Even were that the case, that 20 to 30 years is exactly the time when the combined impact of global warming and oil depletion will severely hamper our ability and desire to upgrade dams to a safe level. Even to bring the world's dams up to levels currently considered safe that investment would be sizable. "But if securing US dams would cost $30 billion [some estimates, in fact, exceed $100 billion for U.S. dams] and the US has an estimated 10% of the world’s dams, a ballpark figure for the global under-investment in dam safety would be $300 billion."[6]
That state of denial also manifests itself at government levels, sometimes in the extreme. The most common and obvious form of this government denial, of course, is in insufficient budget allocations to maintain the dam inventory at safe levels. Following the catastrophic Henan Province cascade dam failure that killed an estimated 230,000 people in 1975, however, "The Chinese government kept the incident secret for about 20 years, but information on the disaster was eventually leaked to the outside world."[6] If this was possible, even in a closed totalitarian state, in an age of instant global communication, what might happen with those catastrophes in 20 to 30 years time in a very changed, power-reduced world?
Few countries have, or can even afford, comprehensive dam inspection/maintenance safety programs. Most, especially in underdeveloped countries, were built with inordinately expensive borrowed funds, monies which are not sufficient to cover future maintenance which may not be needed for 20-30 years after the dam's completion. "Despite the massive risk to human life and property posed by large dams, few countries have comprehensive dam safety legislation. Such laws should cover the engineering criteria that new dams must meet; the regular inspection and repair of old dams; and the preparation of emergency evacuation plans for people living downstream. ..... Studies in the US have shown that where early warning systems and evacuation plans are in place, the fatalities caused by dam bursts are on average reduced by a factor of more than 100. However, such plans have been made for only a handful of the world's dams, mostly in the US, Canada and Australia...."[6]
Even where safety legislation and programs exist, however, it generally treats dams on a one by one basis. Each dam is designed, built, inspected, maintained as though it were a structure in isolation. But most large river systems have, as noted earlier, multiple dams along their course. The excess capacity of any dam is designed to accommodate a particular volume of water from floods or other designed-for events. But they are designed assuming that all other conditions are normal and that the combined infrastructure of dams on the river will remain intact through the event (If I did not already know it instinctively, thirty years of system design experience would have taught me that you never design a system with the assumption it will work perfectly). In other words, a dam designed with a flood containment capacity of 300 million cubic meters assumes that that volume will be delivered by nature. The fact that there is a dam upstream with a capacity of 500 million cubic meters, or a series of dams with a total capacity of a billion cubic meters, is irrelevant in the design.
As we pass peak oil and the budgets and abilities to properly maintain our massive dam inventory diminish over time (time in which those dams continue to age and require increased, not decreased, maintenance) this design shortcoming will become critical for those water courses with multiple dams, which includes most of our large river systems. The risk to any dam on such systems is not the once-in-a-hundred-years or once-in-a-thousand-years flood that the dam is designed to accommodate but rather the combined capacity of all of the dams upstream from that dam plus the hundred-year or thousand-year flood. No one, especially those living along the banks of such river systems, should take any solace from the fact that such events may be twenty or thirty years in the future. That should, in fact, be more a cause for serious concern than solace. That future in which those failures increase in probability is a future of declining energy and infrastructure maintenance budgets and increased climatic extremes, a potentially deadly combination.
====================
Additional reading:
1) Fragmentation Of Riparian Floras In Rivers With Multiple Dams
2) Simulation of Dam Failures in Multidike Reservoirs Arranged in Cascade
3) NOTE: The following emails are reproduced in chronological order ...
4) Federal Guidelines for Dam Safety
5) Revised Criteria for Assigning Hazard Potential Ratings to BLM Dams
6) And The Walls Came Tumbling Down: Dam Safety Concerns Grow in Wake of Failures, Changing Climate
7) 17 Large Dams Under Construction by Basin - Watersheds of the World
8) The Amazon Rainforest
9) The Catastrophic Dam Failures in China in August 1975
Tuesday, August 14, 2007
Our Dangerous Infrastructure
See these other articles in the blog related to infrastructure maintenance;
The myth of permanence: post-peak infrastructure maintenance
The Emerging Global Freshwater Crisis
Lake Ontario & St. Lawrence River after Peak Oil
Post Peak Dam Maintenance, or Lack Thereof
This article concerns the post peak oil dangers represented by the decay of our modern infrastructure. Of all the implications of peak oil and the energy downslope on the other side this is the one least present in the public consciousness or, for that matter, even in the minds of most of those who are peak oil aware. I understand that. Infrastructure is not something we think about. It doesn't grab our attention. It is just there. The only time we are really conscious of it is when it fails, when the levees break in New Orleans or an overpass collapses in Montreal or a bridge falls into the Mississippi in Minneapolis or the grid dies in the entire northeast or an ice storm collapses hydro transmission towers in Quebec.
Very few of us have any connection with the infrastructure that underlies the smooth working of our society. It is invariably designed, built and maintained by an army of people with very specialized knowledge and skills that are outside the purview of the average citizen. That is part of what keeps it invisible to us. Even the infrastructure in our homes is invisible to most of us, the foundation, the framework inside the walls, the plumbing and electrical wiring running through the walls, floors and ceilings, the structure that supports the roof, the little details that let our house breathe. These are all someone else's concern, the hired plumber or electrician or handyman or builder or whoever. We pick up the phone, unconscious of the massive infrastructure that allows that system to work, and call somebody to come fix whatever it is that is broken. We don't care how they do it, just that they do.
But how much of society's resources are tied up in that dependable, invisible infrastructure? What does it cost us all every year?
Take a single piece of infrastructure, a bridge for example. It is designed and built with a planned serviceable lifespan of fifty years. The annual cost of that structure amortized over the planned lifespan is manageable. For the sake of argument, let us say the bridge cost $50-million to build. The annual cost spread over that planned fifty year lifespan is only $1-million per year. During the first half of that lifespan the annual inspection and maintenance costs are minimal. They may be, let's say, between $200,000 and $300,000 each year, averaging $250,000 annually (about one quarter of the annual amortized construction cost) over the first 25 years. From the midway point of the designed lifespan, however, inspection and maintenance costs normally begin to rise steadily. Anyone who has ever tried to keep an aging car on the road understands this. Let us assume that costs rise 4% per year. By the fiftieth year, at a steady rate of increase in maintenance cost, the annual cost will have risen to $666,000, two thirds of the amortized construction cost. If at that stage it is decided to continue to maintain the bridge rather than decommission it or replace it, the annual maintenance costs will rise over the next 25 years to $1,778,000 per year, nearly double the annual amortization cost during the designed lifespan of the bridge.
In a constantly growing economy the amount of newer infrastructure is always greater than the amount of aging infrastructure, the average age generally half or less than the overall average designed lifespan. Under such circumstances prioritizing and paying for the cost of maintenance for the relatively small amount of aging infrastructure is not a big issue, particularly where there is some form of centralized or collective budgeting (government?) for that cost to be spread over the whole infrastructure budget. The percentage of the overall infrastructure budget committed for maintenance is relatively low. In a declining economy, however, where the infrastructure is always pushed just a little bit further, expected to last just a little bit longer, where the average age of the infrastructure inventory steadily increases toward and then beyond the designed service life, not only does the ratio of maintenance cost to development cost increase but, as the overall infrastructure inventory exceeds its design lifespan the cost of proper maintenance will actually reach the point where it exceeds what would have been the amortized construction cost of new infrastructure. The decision to push the infrastructure to stay in service longer, because of the declining economy, is not made with a clear and honest understanding and admission that the maintenance costs will continue to grow. In fact, more often than not such decisions are probably made concurrent with a decision to decrease or, at best, hold the line on the maintenance budget. This should not be surprising to anyone. Even in this age of a constantly growing economy maintenance budgets are invariably underfunded and maintenance short cuts are the norm rather than the exception.
The reason that the amount of new infrastructure developed in a shrinking economy decreases is not because the infrastructure is any less needed than it was when the economy was growing. It is because the cost of new infrastructure is higher than can be justified in a shrinking economy. The cost exceeds the need. In a declining economy the overall infrastructure budget shrinks. Why, then, would one expect those budgets to suddenly and miraculously increase to meet the escalating needs of infrastructure maintenance when those maintenance costs rise above the level it would take to develop new infrastructure? The budget for infrastructure maintenance in that declining economy will have shrunk proportional to the budget for new infrastructure because "everybody knows" maintenance is always a proportion of the cost of new infrastructure. If the amount of new infrastructure is declining, obviously, so too should the amount set aside for maintenance. This is a mindset that is not likely to be easily changed just because the economy is shrinking.
The current U.S. infrastructure maintenance/renewal backlog is estimated at $1.6-trillion, Canada's between $60-125-billion. The dollar value of the infrastructure in need of that maintenance is probably inestimable at this stage, with over 600,000 bridges and 75,000 dams in the U.S. alone. They were essentially all designed and built with a planned service life of fifty years. The average age of all of that infrastructure, as a result, most of it built between 1950 and the late 1970s, has now exceeded half the serviceable lifespan with as much as one quarter of that infrastructure having already exceeded its full designed service lifespan. And the maintenance backlog continues to grow and the infrastructure inventory continues to age. Canada's maintenance backlog is estimated to be growing by $2-billion annually, the U.S. backlog between $25-50-billion, almost equal the total of the $30-billion annual infrastructure maintenance budget.
As the age of any unit of infrastructure increases and the maintenance costs begin to climb there will most often be a period of time when those rising costs are absorbed through a process of "creative accounting". This is generally done on an assumption that the higher costs are a temporary aberration. As the cost increases develop into a trend, however, it becomes increasingly difficult to "hide" and absorb the rising costs. Those increases must be dealt with, and are usually dealt with by recommending that the unit be upgraded or replaced and/or imposing limits on the maintenance that will be done in order to keep the maintenance costs within budget. It's not unlike what you do when the maintenance costs on your aging car suddenly shoot up. At first you just absorb it, figuring it is a temporary situation. As it becomes a regular event, though, you suddenly have some decisions to make. Do you continue to absorb the cost? Increase you vehicle maintenance budget? Decide to avoid certain types of maintenance that you decide is non-critical? Or decide to start looking for another car? Or do you consider leasing rather than buying? If you are confident your job will continue and your salary will continue to increase you probably decide to replace. But if your job is threatened or the company is imposing salary limitations or salary cuts or your confidence in your future earnings potential is otherwise shaken, you may be forced to consider other options.
That is the situation our society, national and global, will be facing as we pass peak oil and it begins to have a destructive impact on the national and global economy. The first victim of budget cuts is almost invariably maintenance. Investigations following most major infrastructure failures, even in a vibrant economy, highlight insufficient or ineffective maintenance as the key factor in the failure. That is followed by design flaws, either from an engineering perspective or from an insufficient understanding of the failure criteria.
Let us be clear. Neither design flaws nor shortcomings in infrastructure maintenance are a guarantee that the infrastructure will suffer a catastrophic failure. Considering the nearly 700,000 bridges and dams in operation in the U.S. the number of catastrophic failures are surprisingly low. They stick in the public consciousness because they are catastrophic, like a plane crash that kills three hundred people compared to the same number dying in two hundred different car accidents. The plane crash is global news. The two hundred car accidents are buried on the inside pages of two hundred local newspapers.
But this is the nature of air travel and of major infrastructure. When it fails it is serious business. People die, often in large numbers. When the levees failed in New Orleans after Hurricane Katrina thousands of people perished. The 1963 failure of the Vajont dam in Italy claimed 2,500 lives. In the catastrophic dam failure in China in 1975 over 85,000 people died. The Val di Stava dam collapse in Italy in 1985 took another 268 lives. Railway crashes, often due to infrastructure failure, regularly take hundreds of lives. Even as you read this the so-called Saddam dam that holds back the waters of the Tigris River in northern Iraq is in imminent danger of collapse and under constant surveillance. It is no longer a question of if the dam will fail, just a question of when. When it does fail, a wall of water will sweep into Mosul, Iraq's third largest city with a population of 1.7 million, 20 miles to the south. Once the dam fails evacuation will no longer be an option. That wall of water will reach Mosul in minutes.
Our major infrastructure, especially that like dams, levees and bridges that deal with water, are very dangerous when they fail. Unfortunately, without proper maintenance and timely replacement or decommissioning failure is an eventual certainty. The only uncertainty is when that failure will occur. In that regard it is important to note that all of our infrastructure, especially that designed and built since WWII, has a designed life-span. That life-span is generally planned to be fifty years. In fairness, generally infrastructure can be retained in service safely for an extra half of it's designed life-span. In general, therefore, with proper maintenance that infrastructure designed to last fifty years can be safely operated for seventy-five years. Some can and does function much longer than that. The Brooklyn Bridge, for example, was opened in 1883 and is still in service today 124 years later, despite both design and construction flaws. The bridge has, however, failed its latest safety inspection and its days may be numbered. It is important to note that the Manhattan tower of the bridge has always rested on sand, thirty feet short of the underlying bedrock. With hundreds of thousands of vehicles crossing the bridge daily and hundreds or even thousands on the bridge at any given time, the risk of any failure being catastrophic is simply too great to continue to push the limits.
If peak oil results in the economic failure that most analysts expect and if it occurs within the next ten to fifteen years, which is almost guaranteed, it could not come at a worse time when looking at the aging infrastructure around us. Over 80% of our current, major, functioning infrastructure was built in the quarter century beginning in 1950 or earlier. Over 50% of that infrastructure will have exceeded its designed service life by 2025. By the middle of this century almost all of that infrastructure currently in service will have reached or exceeded its designed lifespan. In this same timeframe, unfortunately, the national and global economy will probably be in a period of severe contraction due to the impact of global peak oil. It is unlikely in a contracting economy that infrastructure, regardless of it's age, will be replaced or, perhaps, even properly decommissioned. Efforts will be made to keep that infrastructure in service as long as possible, or longer. But peak oil will hit, the global economy will go into terminal decline at the very time when most of our infrastructure seriously needs replacement or decommissioning.
Major infrastructure is increasingly dangerous as it ages beyond its designed service life, even with proper maintenance. Every dam represents a serious danger to those living or working downstream from it. Every major aging bridge crossing any waterway is an increasing risk to those who continue to use it when it has surpassed its reasonable age of serviceability. But by the middle of this century virtually all of our major infrastructure will reach that age, and will probably do so without proper maintenance performed on it possibly for decades.
If a bridge gets too old and too unsafe to use ultimately it can simply be closed off and left to fail. Unless something happens to be under it at the time of collapse it probably won't be a catastrophe. Dams and levees, however, are another matter. They don't pass over water. They hold back water, tremendous volumes of water. If those structures failure the sudden unleashing of all that water will be catastrophic, regardless of where that structure is. Over ten percent of our dams and levees hold back water from major population centers, many from cities of millions of people, like the risk posed to Mosul by the Saddam dam. When they fail, which they will if not eventually decommissioned or replaced, the results will be unquestionably catastrophic. Unlike bridges, dams and levees represent an ongoing and increasing risk regardless of whether we are "using" them or not. They can't simply be blocked off and left to fail with no resulting loss of life or property. A bridged blocked off no longer has traffic crossing it to be at risk. A dam blocked off still holds back billions of gallons of water capable of inundating the land downstream and potentially destroying anything or anyone in its path.
If we enter the anticipated era of declining global economy with a general and, more importantly, leadership mindset that still believes the invisible hand of the markets will right all problems, our infrastructure woes and the risks involved will continue to worsen. That belief in the ability of the markets to correct themselves is based on an assumption that the state of normalcy to which the markets will eventually return is one of growth. That assumption is, however, based on endless consumption of resources supported by an endless and reliable supply of energy. Once we pass peak oil neither will possible. The state of decline, for all practical purposes, will be permanent.
The first victim in any budget cuts is almost always the maintenance budget. The first priority for business, and probably government as well, in a declining economy will be to do whatever is necessary to keep profits up while sales are declining, again based on an assumption that overtime sales will return to a pattern of growth. This invariably means cutting costs. Profits invariably mean growth, the willingness of a society to pay more for goods than their real value (the profits) in a belief that that value will increase with time. In an environment of perpetual economic decline this will not be possible. The longer any business or nation tries to hold on in a belief that things will get back to normal the more assured is their eventual collapse.
The cutting of maintenance budgets in a downturn is, like all other cost-cutting measures, assumed to be a necessary and temporary adjustment. It is assumed that when things turn around that deferred maintenance will be caught up. But when there is no turn around, no correction, no return to normal growth on the horizon, the maintenance deficit and the risks implicit in that deficit continue to worsen. When the infrastructure with which those risks are being taken, for which maintenance is being "temporarily" deferred, is already near, at or beyond its designed service life those decisions put society in general at serious risk. This is critically so with dams, levees, bridges and other water management infrastructure.
Facing the reality of peak oil and the implications for our economy and society is no longer an option, no longer something that can be denied or avoided. There is far too much risk to society in a do-nothing, laissez-faire approach. Doing nothing simply increases the risk and threat. We need to face that reality, face the implications, make the decisions and begin the corrective action necessary before peak oil is upon us and before the global economy slides into a state of perpetual decline. The resources, particularly financial, will simply not be available to take the appropriate action if we wait for that event to push us into action.
I am not optimistic that we will do what needs to be done. All of the historical evidence suggests that we will not. One can only hope and add one's voice to the demands for appropriate and timely action.
The myth of permanence: post-peak infrastructure maintenance
The Emerging Global Freshwater Crisis
Lake Ontario & St. Lawrence River after Peak Oil
Post Peak Dam Maintenance, or Lack Thereof
This article concerns the post peak oil dangers represented by the decay of our modern infrastructure. Of all the implications of peak oil and the energy downslope on the other side this is the one least present in the public consciousness or, for that matter, even in the minds of most of those who are peak oil aware. I understand that. Infrastructure is not something we think about. It doesn't grab our attention. It is just there. The only time we are really conscious of it is when it fails, when the levees break in New Orleans or an overpass collapses in Montreal or a bridge falls into the Mississippi in Minneapolis or the grid dies in the entire northeast or an ice storm collapses hydro transmission towers in Quebec.
Very few of us have any connection with the infrastructure that underlies the smooth working of our society. It is invariably designed, built and maintained by an army of people with very specialized knowledge and skills that are outside the purview of the average citizen. That is part of what keeps it invisible to us. Even the infrastructure in our homes is invisible to most of us, the foundation, the framework inside the walls, the plumbing and electrical wiring running through the walls, floors and ceilings, the structure that supports the roof, the little details that let our house breathe. These are all someone else's concern, the hired plumber or electrician or handyman or builder or whoever. We pick up the phone, unconscious of the massive infrastructure that allows that system to work, and call somebody to come fix whatever it is that is broken. We don't care how they do it, just that they do.
But how much of society's resources are tied up in that dependable, invisible infrastructure? What does it cost us all every year?
Take a single piece of infrastructure, a bridge for example. It is designed and built with a planned serviceable lifespan of fifty years. The annual cost of that structure amortized over the planned lifespan is manageable. For the sake of argument, let us say the bridge cost $50-million to build. The annual cost spread over that planned fifty year lifespan is only $1-million per year. During the first half of that lifespan the annual inspection and maintenance costs are minimal. They may be, let's say, between $200,000 and $300,000 each year, averaging $250,000 annually (about one quarter of the annual amortized construction cost) over the first 25 years. From the midway point of the designed lifespan, however, inspection and maintenance costs normally begin to rise steadily. Anyone who has ever tried to keep an aging car on the road understands this. Let us assume that costs rise 4% per year. By the fiftieth year, at a steady rate of increase in maintenance cost, the annual cost will have risen to $666,000, two thirds of the amortized construction cost. If at that stage it is decided to continue to maintain the bridge rather than decommission it or replace it, the annual maintenance costs will rise over the next 25 years to $1,778,000 per year, nearly double the annual amortization cost during the designed lifespan of the bridge.
In a constantly growing economy the amount of newer infrastructure is always greater than the amount of aging infrastructure, the average age generally half or less than the overall average designed lifespan. Under such circumstances prioritizing and paying for the cost of maintenance for the relatively small amount of aging infrastructure is not a big issue, particularly where there is some form of centralized or collective budgeting (government?) for that cost to be spread over the whole infrastructure budget. The percentage of the overall infrastructure budget committed for maintenance is relatively low. In a declining economy, however, where the infrastructure is always pushed just a little bit further, expected to last just a little bit longer, where the average age of the infrastructure inventory steadily increases toward and then beyond the designed service life, not only does the ratio of maintenance cost to development cost increase but, as the overall infrastructure inventory exceeds its design lifespan the cost of proper maintenance will actually reach the point where it exceeds what would have been the amortized construction cost of new infrastructure. The decision to push the infrastructure to stay in service longer, because of the declining economy, is not made with a clear and honest understanding and admission that the maintenance costs will continue to grow. In fact, more often than not such decisions are probably made concurrent with a decision to decrease or, at best, hold the line on the maintenance budget. This should not be surprising to anyone. Even in this age of a constantly growing economy maintenance budgets are invariably underfunded and maintenance short cuts are the norm rather than the exception.
The reason that the amount of new infrastructure developed in a shrinking economy decreases is not because the infrastructure is any less needed than it was when the economy was growing. It is because the cost of new infrastructure is higher than can be justified in a shrinking economy. The cost exceeds the need. In a declining economy the overall infrastructure budget shrinks. Why, then, would one expect those budgets to suddenly and miraculously increase to meet the escalating needs of infrastructure maintenance when those maintenance costs rise above the level it would take to develop new infrastructure? The budget for infrastructure maintenance in that declining economy will have shrunk proportional to the budget for new infrastructure because "everybody knows" maintenance is always a proportion of the cost of new infrastructure. If the amount of new infrastructure is declining, obviously, so too should the amount set aside for maintenance. This is a mindset that is not likely to be easily changed just because the economy is shrinking.
The current U.S. infrastructure maintenance/renewal backlog is estimated at $1.6-trillion, Canada's between $60-125-billion. The dollar value of the infrastructure in need of that maintenance is probably inestimable at this stage, with over 600,000 bridges and 75,000 dams in the U.S. alone. They were essentially all designed and built with a planned service life of fifty years. The average age of all of that infrastructure, as a result, most of it built between 1950 and the late 1970s, has now exceeded half the serviceable lifespan with as much as one quarter of that infrastructure having already exceeded its full designed service lifespan. And the maintenance backlog continues to grow and the infrastructure inventory continues to age. Canada's maintenance backlog is estimated to be growing by $2-billion annually, the U.S. backlog between $25-50-billion, almost equal the total of the $30-billion annual infrastructure maintenance budget.
As the age of any unit of infrastructure increases and the maintenance costs begin to climb there will most often be a period of time when those rising costs are absorbed through a process of "creative accounting". This is generally done on an assumption that the higher costs are a temporary aberration. As the cost increases develop into a trend, however, it becomes increasingly difficult to "hide" and absorb the rising costs. Those increases must be dealt with, and are usually dealt with by recommending that the unit be upgraded or replaced and/or imposing limits on the maintenance that will be done in order to keep the maintenance costs within budget. It's not unlike what you do when the maintenance costs on your aging car suddenly shoot up. At first you just absorb it, figuring it is a temporary situation. As it becomes a regular event, though, you suddenly have some decisions to make. Do you continue to absorb the cost? Increase you vehicle maintenance budget? Decide to avoid certain types of maintenance that you decide is non-critical? Or decide to start looking for another car? Or do you consider leasing rather than buying? If you are confident your job will continue and your salary will continue to increase you probably decide to replace. But if your job is threatened or the company is imposing salary limitations or salary cuts or your confidence in your future earnings potential is otherwise shaken, you may be forced to consider other options.
That is the situation our society, national and global, will be facing as we pass peak oil and it begins to have a destructive impact on the national and global economy. The first victim of budget cuts is almost invariably maintenance. Investigations following most major infrastructure failures, even in a vibrant economy, highlight insufficient or ineffective maintenance as the key factor in the failure. That is followed by design flaws, either from an engineering perspective or from an insufficient understanding of the failure criteria.
Let us be clear. Neither design flaws nor shortcomings in infrastructure maintenance are a guarantee that the infrastructure will suffer a catastrophic failure. Considering the nearly 700,000 bridges and dams in operation in the U.S. the number of catastrophic failures are surprisingly low. They stick in the public consciousness because they are catastrophic, like a plane crash that kills three hundred people compared to the same number dying in two hundred different car accidents. The plane crash is global news. The two hundred car accidents are buried on the inside pages of two hundred local newspapers.
But this is the nature of air travel and of major infrastructure. When it fails it is serious business. People die, often in large numbers. When the levees failed in New Orleans after Hurricane Katrina thousands of people perished. The 1963 failure of the Vajont dam in Italy claimed 2,500 lives. In the catastrophic dam failure in China in 1975 over 85,000 people died. The Val di Stava dam collapse in Italy in 1985 took another 268 lives. Railway crashes, often due to infrastructure failure, regularly take hundreds of lives. Even as you read this the so-called Saddam dam that holds back the waters of the Tigris River in northern Iraq is in imminent danger of collapse and under constant surveillance. It is no longer a question of if the dam will fail, just a question of when. When it does fail, a wall of water will sweep into Mosul, Iraq's third largest city with a population of 1.7 million, 20 miles to the south. Once the dam fails evacuation will no longer be an option. That wall of water will reach Mosul in minutes.
Our major infrastructure, especially that like dams, levees and bridges that deal with water, are very dangerous when they fail. Unfortunately, without proper maintenance and timely replacement or decommissioning failure is an eventual certainty. The only uncertainty is when that failure will occur. In that regard it is important to note that all of our infrastructure, especially that designed and built since WWII, has a designed life-span. That life-span is generally planned to be fifty years. In fairness, generally infrastructure can be retained in service safely for an extra half of it's designed life-span. In general, therefore, with proper maintenance that infrastructure designed to last fifty years can be safely operated for seventy-five years. Some can and does function much longer than that. The Brooklyn Bridge, for example, was opened in 1883 and is still in service today 124 years later, despite both design and construction flaws. The bridge has, however, failed its latest safety inspection and its days may be numbered. It is important to note that the Manhattan tower of the bridge has always rested on sand, thirty feet short of the underlying bedrock. With hundreds of thousands of vehicles crossing the bridge daily and hundreds or even thousands on the bridge at any given time, the risk of any failure being catastrophic is simply too great to continue to push the limits.
If peak oil results in the economic failure that most analysts expect and if it occurs within the next ten to fifteen years, which is almost guaranteed, it could not come at a worse time when looking at the aging infrastructure around us. Over 80% of our current, major, functioning infrastructure was built in the quarter century beginning in 1950 or earlier. Over 50% of that infrastructure will have exceeded its designed service life by 2025. By the middle of this century almost all of that infrastructure currently in service will have reached or exceeded its designed lifespan. In this same timeframe, unfortunately, the national and global economy will probably be in a period of severe contraction due to the impact of global peak oil. It is unlikely in a contracting economy that infrastructure, regardless of it's age, will be replaced or, perhaps, even properly decommissioned. Efforts will be made to keep that infrastructure in service as long as possible, or longer. But peak oil will hit, the global economy will go into terminal decline at the very time when most of our infrastructure seriously needs replacement or decommissioning.
Major infrastructure is increasingly dangerous as it ages beyond its designed service life, even with proper maintenance. Every dam represents a serious danger to those living or working downstream from it. Every major aging bridge crossing any waterway is an increasing risk to those who continue to use it when it has surpassed its reasonable age of serviceability. But by the middle of this century virtually all of our major infrastructure will reach that age, and will probably do so without proper maintenance performed on it possibly for decades.
If a bridge gets too old and too unsafe to use ultimately it can simply be closed off and left to fail. Unless something happens to be under it at the time of collapse it probably won't be a catastrophe. Dams and levees, however, are another matter. They don't pass over water. They hold back water, tremendous volumes of water. If those structures failure the sudden unleashing of all that water will be catastrophic, regardless of where that structure is. Over ten percent of our dams and levees hold back water from major population centers, many from cities of millions of people, like the risk posed to Mosul by the Saddam dam. When they fail, which they will if not eventually decommissioned or replaced, the results will be unquestionably catastrophic. Unlike bridges, dams and levees represent an ongoing and increasing risk regardless of whether we are "using" them or not. They can't simply be blocked off and left to fail with no resulting loss of life or property. A bridged blocked off no longer has traffic crossing it to be at risk. A dam blocked off still holds back billions of gallons of water capable of inundating the land downstream and potentially destroying anything or anyone in its path.
If we enter the anticipated era of declining global economy with a general and, more importantly, leadership mindset that still believes the invisible hand of the markets will right all problems, our infrastructure woes and the risks involved will continue to worsen. That belief in the ability of the markets to correct themselves is based on an assumption that the state of normalcy to which the markets will eventually return is one of growth. That assumption is, however, based on endless consumption of resources supported by an endless and reliable supply of energy. Once we pass peak oil neither will possible. The state of decline, for all practical purposes, will be permanent.
The first victim in any budget cuts is almost always the maintenance budget. The first priority for business, and probably government as well, in a declining economy will be to do whatever is necessary to keep profits up while sales are declining, again based on an assumption that overtime sales will return to a pattern of growth. This invariably means cutting costs. Profits invariably mean growth, the willingness of a society to pay more for goods than their real value (the profits) in a belief that that value will increase with time. In an environment of perpetual economic decline this will not be possible. The longer any business or nation tries to hold on in a belief that things will get back to normal the more assured is their eventual collapse.
The cutting of maintenance budgets in a downturn is, like all other cost-cutting measures, assumed to be a necessary and temporary adjustment. It is assumed that when things turn around that deferred maintenance will be caught up. But when there is no turn around, no correction, no return to normal growth on the horizon, the maintenance deficit and the risks implicit in that deficit continue to worsen. When the infrastructure with which those risks are being taken, for which maintenance is being "temporarily" deferred, is already near, at or beyond its designed service life those decisions put society in general at serious risk. This is critically so with dams, levees, bridges and other water management infrastructure.
Facing the reality of peak oil and the implications for our economy and society is no longer an option, no longer something that can be denied or avoided. There is far too much risk to society in a do-nothing, laissez-faire approach. Doing nothing simply increases the risk and threat. We need to face that reality, face the implications, make the decisions and begin the corrective action necessary before peak oil is upon us and before the global economy slides into a state of perpetual decline. The resources, particularly financial, will simply not be available to take the appropriate action if we wait for that event to push us into action.
I am not optimistic that we will do what needs to be done. All of the historical evidence suggests that we will not. One can only hope and add one's voice to the demands for appropriate and timely action.
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