We're Paying the Price Today for Decades of Relentless Dam Building
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Between 1950 and 1970, three new dam projects were started every single day in the world. Today, primarily in China, Turkey, Brazil, Japan and India, one new dam project begins daily with an average completion date of four years. Fifteen hundred dams are currently under construction worldwide.
Dams fragment, divert and subjugate the world's rivers. In one long lifespan, beginning with the inauguration of Hoover Dam in 1936, the engineering marvel of the 20th century, civilization has altered the most important function that makes the earth work, water. Thus, transmuting humanity into something foreign to the earth it inhabits -- a stranger to the very system which gave rise to our species.
The late Carl Sagan was among precious few visionary humans who shared the extraordinary ability to differentiate between deep thought and deep nonsense and recognized the persistence of a satisfying delusion to perpetuate the latter. Dr. Sagan wrote, "We go about our daily lives understanding almost nothing of the world. We give little thought to the machinery that generates the sunlight that makes life possible, to the gravity that glues us to an earth that otherwise sends us spinning off into space or to the atoms of which we are made and on whose stability we fundamentally depend."
Without some sense, some outline of how the earth works and our relationship to it, one is deprived of knowing, let alone of asking, the really important questions that promote regenerative life and prevent massive-scale destruction and degeneration.
It is only in blindness that ignorance can find engineering arrogance and feed the certainty of human expediency -- that millions of dams can exist worldwide strangling the lubricant of life itself. It is true that dams have created a seemingly unlimited oasis in arid and semi-arid regions of the world and have produced unimaginable population centers in water-stressed locations, made possible food production on marginal arid lands, and provided cheap taxpayer subsidized water and artificial lakes aplenty for fishing, camping and boating.
It seems a good thing, yet, what isn't accounted for is the short-term duration and ecological costs. It has created this artificial bonanza by short-circuiting the natural system of limitations much as the one time wonder of fossil fuels has short-circuited and driven the industrial revolution. The debts of temporary prosperity are all due and payable in the 21st century.
In the present state of affairs, water, energy, population, war, global economic expansionism, and failing ecological systems are sending shockwaves throughout the vulnerable global community while staggering the biosphere which keeps us among the living tentatively.
The world's water budget is a fixed volume and has remained unchanged for roughly 2.2 billion years in its present state. About 1 percent of the world's total water circulates as freshwater while oceans represent 97 percent of the world's stores and the remaining 2 percent is tied up in glaciers and polar ice caps. This finite water pie divides ever more thinly as population, agriculture and the industrial economy expands.
The uninterrupted Earth is a dynamic solar and geothermal energy system which powers the hydrologic and rock cycles. It conducts and convects energy flows from the earth's 10,000 degree iron core outward through the mantle and lithosphere (crust) generating plate collisions that move continents and trip earthquakes. Magma driven plate collisions uplift mountain ranges and setoff volcanoes recycling lava and gases on land and underwater replenishing both with life-producing minerals.
Solar energy evaporates surface water primarily from oceans to atmosphere to land as water or snow. Erosive rainfall or expanding ice in rock crevices tears down mountains as fast as they rise. The Earth's lumpy land surface is a massive drainage system. From high to low, meandering and networked creeks and rivers drive the rock and mineral cycle. A river system operates on the principle of erosion and deposition. As a river gains water volume and speeds up it erodes and picks up rock and sediment. As it loses volume and slows down it drops some of its load. Large pulses of water flush sediments onto the rivers floodplain creating fertile soil before arriving at its delta entry to the sea.
Remaining sediments combine with the heavy basalt sea floor at the shoreline which is being subducted under the lighter continental plate from volcanic spreading forces at the Mid-Oceanic Ridge. This continuous underwater volcanic ridge runs like the seams of a baseball throughout the world's oceans. Everything cycles like a big conveyor; from Mid-Oceanic Ridge pushing the sea floor towards continental plates where it subducts back into the mantle to raise a mountain or explode through a volcano over geologic time. Dams, known as nickpoints, interrupt and distort the natural transport machinery between land and sea.
Dams quiet the waters and backfill canyons forming massive lakes that produce and release vast amounts of methane from rotting vegetation underwater. The energy-deprived river unloads its rock and sediment load filling the reservoir, predicting its eventual self-cancellation by virtue of sedimentation fill. The only question is how will it end and what will civilization do when it does? What engineering-dominate options remain to further alter, manipulate or control the world?
The National Inventory on Dams shows the United States has constructed 79,000 dams large enough to require state and federal monitoring. These higher risk categories are often located near enough to population centers to pose a direct safety risk to human life and property. Worldwide, there are 800,000 similarly sized dams that are regulated and present equal challenges. Inventoried or not, total dams in the US may exceed 2.5 million and perhaps tens of millions worldwide. They interrupt and fragment the rock cycle and flow of more than 60 percent of the world's major rivers with one or more large dams.
The International Commission on Large Dams reveals 45,000 dams of the world are mega-whoppers with heights up to 1,000 feet and volume capacities exceeding many million acre feet (MAF) of water.
A recent study measured the volume capacities of 29,484 large reservoirs throughout the world. It determined their storage capacity was about 8.7 billion acre feet (BAF) of freshwater. That's enough water to make a nine foot lake out of Alaska, Texas, California, Montana, New Mexico, Arizona, and Nevada combined. This immense artificial above-ground storage is counter intuitive to nature's freshwater storage system which stores only .016 percent of all the circulating freshwater in all natural lakes, rivers, streams, creeks and atmosphere combined -- preferring instead to store 80 percent to 90 percent of the world's circulating freshwater underground free from evaporation and sedimentation.
Still more revealing is the loss of artificial reservoir stores through evaporation. Although evaporation rates vary from region to region, a 1998 U.S. Geologic Survey (USGS) study of California's reservoirs in all nine major hydrologic regions recorded 2,342,800 AF of evaporation, about .06 percent of California's 40 MAF of reservoir storage. Using a back-of-the-envelope estimation applying .06 percent evaporation rate to the world's 8.7 BAF of reservoir stored water yields 522 MAF of evaporation which is about 2.5 years of total California rainfall and 16 years of California water draws for agriculture. That's water that doesn't infiltrate as groundwater to feed wells or perennial streams, or grow food, or evapotranspire through wetlands, grasslands, woodlands, and forests, or provide water for wildlife (aquatic and terrestrial) and the billion humans on the planet who don't have access to unpolluted water.
The World Commission on Dams estimates that 3.1 billion acre foot of freshwater is withdrawn (as opposed to total stores) from lakes, rivers, and aquifers annually. That equals the total discharge of 7 Mississippi Rivers, or 22 Columbia Rivers, or 221 Colorado Rivers. Here again it would cover with 3 foot of water the above mentioned seven states totaling 1 billion surface acres and is 93 times the amount of water drawn from all California reservoirs by agriculture annually -- a lot of water. The 3.1 billion acre foot number is still more revealing when one considers that over and above storage and withdrawals, most nearly 65 percent of all rainfall evaporates before it can become part of either surface or groundwater stores.
Aside from warming atmospheric conditions, and considering only current global population additions (80 million per year), the equivalent of adding a new Germany annually, and factoring rising water consumption rates which triple with each population doubling, all of human enterprises will consume and significantly pollute 90 percent of all the available freshwater by 2025 leaving a scant 10 percent to support the earths dwindling water-dominant ecosystem.
Are we playing against ourselves?
When 1964 American Nobel Prizing-winning physicist Charles Townes down-played his break-out laser technology with reporters he demurred, "When I hear that kind of thing, it reminds me of what the beaver told the rabbit as they stood at the base of Hoover Dam: 'No, I didn't build it myself, but it's based on an idea of mine.'"
In the 1960's, the age without limits, this telling remark reflects how little was known and understood about the natural world and the accumulative impacts of dams. Since the idea of the beaver wasn't to dam major rivers but build small organic dams on its many tributaries. And then these temporary ecosystems evolved and produced abundant life. They reduced flooding and erosion, enhanced groundwater penetration, created the valley's precious topsoil and fed a radiant food web including decomposing bacteria, amphibians, fisheries, insects, birds, herbivores and carnivores. Comparing a beaver to Hoover Dam is like comparing life to death. Aldo Leopold, the legendary and visionary U.S. Forest Service land manager of the 1920s, 30s, and 40s said dams make the land sick and provide only a temporary prosperity followed by tremendous vulnerability. This ecological reality is incontrovertible -- all dams have an end date.
California leads the list with dams near self-cancellation. Within the next generation, 85 percent of all U.S. dams will have degenerated to the point of exhausting their operational lifespan of fifty years requiring decommissioning or massive repairs and upgrades. Now consider that every sweet spot in every geologically sane canyon that might reasonably hold a dam already has an aging dam, what then?
Let's pause for just a moment and ask some relevant questions. What will it cost to maintain, repair, upgrade, and build new dams to replace those that fail or are decommissioned, and restore dysfunctional watersheds impacted by dams? Let me proffer a worldwide estimate to maintain the current population of 6.7 billion without any further additions.
Factoring ecological restoration, maintenance, repair, decommissioning, and replacement cost of the world's developed water infrastructure as it's currently engineered would likely be a cost greater than all the energy expended on all engineering projects from the beginning of civilization and this cost would recur every fifty years or so. Now factor in a population adding 1 billion every thirteen years?
Is it even possible at this stage of civilization to convince people to care about a time on earth that many will not have to live in?
These statistics and trajectories have no caution value to a species front-row seated as the primary agent of geologic change on Earth. For example, in three long lifespans, Europeans have altered a continuous American wilderness into a networked, layered, and interwoven mass of asphalt-spreading, carbon-coughing, concrete-lining, pipeshed-connecting, aqueduct-flowing, levee-bunkering, grid-generating, wireless-transmitting, urban-sprawling, mall-cloning, river-damming, and resource-consuming experiment in human unconsciousness.
Dams provide that tempting illusion of prosperity whose short-term gains literally vandalize the future of civilization and natural terrestrial and aquatic biodiversity. This reality remains an abstraction to a developed and developing world breast-fed on cheap energy, cheap water, and unconscious consumption of finite resources.
The tenant of the economic element states clearly that the natural state of soil, rainfall, creeks and streams, forests, valleys, wetlands, deserts, mountains, etc. have no intrinsic value in and of themselves. And only those aspects that can be justified as an economic benefit to mankind first (logging, mining, damming, intensive agricultural production, urban development, or recreation) are redeemable and can be supported in so far as they produce artificial wealth through income generation. Commodification of elements cycling and recycling from the basement of time, as its sole recognized value displays an arrogance not intended by nature or nature's god.
If the current growing population of 6.7 billion is considered a benefit to mankind, than dams are beneficial. If the vulnerability of dense populations downstream of dams is a benefit to mankind, than dams are beneficial. If agricultural production on arid lands that require large volumes of water that salinate the soil and demand large inputs of fossil-fuel based fertilizers and pesticides that runoff and pollute groundwater is considered a benefit to mankind, than dams are beneficial. If the displacement of 80 million people from their homelands to accommodate dams is a benefit to mankind, than dams are beneficial. If the destruction of life-supporting ecosystems and fishery resources is a benefit to mankind, than dams are beneficial. If the inequitable sharing of benefits and costs is a benefit to mankind, than dams are beneficial. If debt burden, cost overruns, deferred maintenance costs and the impoverishment of people is a benefit to mankind, than dams are the most beneficial engineering endeavor of human history second only to nuclear weapons. If that's the guess then God help us, because common sense hasn't.