Guest Opinion: Dr. Tim Ball
Petula Clark sang, “Don’t sleep in the subway, darling. Don’t stand in the pouring rain.” More helpful advice would urge, “Don’t live in the floodplain, darling. Don’t you know it’s pouring rain?” It’s called a floodplain for a reason. The dangers of flooding mostly involve people living in dangerous places. Why are people allowed to live in these regions without being forced to accept full responsibility for their actions? They are encouraged by governments and insurance that enable bad practices, questionable, and unnecessary behavior.
There was a time when living near a river was important for transport, water supply, waste removal, and even food supply. We don’t need to live close to rivers or at least within the area identified as the floodplain. If you live there, flooding is inevitable, even if flooding protection is in place. In fact, the protection creates a false sense of security. Inevitably the protection will fail through neglect, accident, or water levels that exceed the design capacity.
Engineers design flood control structures based on the frequency of events. Usually, it is for the one in 100-year event. Most think this means if you have such an event then another one will not occur for another 100 years. It is known be a few names the return period, recurrence interval, repeat interval, or expected frequency. It is defined by
Where n = number of years: m = number of occurrences of flood events
There are several problems with this approach, many now producing headlines about global warming and climate change.
The first involves the changing patterns of precipitation. There are very few records of precipitation, and most are less than 100 years long. The greatest range of variation of precipitation occurs in the middle latitudes in association with the changes in the latitude and amplitude in Rossby Waves along the Polar Front. Much longer time periods of precipitation are now occurring. These are not because of man-made climate change but the natural mechanism. The IPCC don’t consider these because of the restrictions of the definition of climate change to only human causes.
Second are the ongoing changes to the river as flows vary with changing precipitation. These are superimposed on the natural changes in a river as it evolves from youth to maturity to old age.
Third are man-made changes in the river basin that alter the pattern of runoff spatially and temporally.
All these issues confronted the Assiniboine River Management Advisory Board I was appointed to Chair. We were charged with creating a total basin management strategy. (Figure 1)
Figure 1
The first challenge was to come to grips with the great range of flow. Like most Great Plain’s rivers, it varied considerably. Fortunately, what triggered the demand for a management strategy was a swing in 6 years from the lowest to the highest flow in the then 94-year record. Figure 3 only covers from 1906 to 1973 but illustrates the range of maximum and minimum flows. Sedimentary evidence indicates much longer and larger scale wetter cycles. For example, Figure 2a, 2b, and 2c are cross-sections through a dune located half way along the current Assiniboine River near Brandon. They show three distinct well-formed paleosols formed through prolonged wetter spells.
Figure 2a (Source: Author).
Figure 2b Top of Dune – Two paleosols visible
Figure 2 c Middle dune paleosol.
The flow rate was important along the river, but also because the Assiniboine is the major tributary of the Red River of the North. The Red consistently causes urban flooding problems at Minot, Fargo in North Dakota, and Winnipeg. The City of Winnipeg built a massive diversion channel called the floodway that takes water out of the River south of the city and returns it north of the city (Figure 4). It effectively doubles the river capacity over the length of the diversion channel. It was built based on the modern record of flooding. The recurrence frequency considered a one-in-100-year flood including the 1950 event that triggered demand for flood control.
In fact, precipitation pattern changes much more frequently and widely than any 100-year record could accommodate. They ignored the historical evidence of the 1826 flood that was three times larger and reports of an even bigger flood in 1776, which coincides with the Little Ice Age. The 1826 flood was approximately a one-in-400-year event. Another flood of this magnitude occurred in 1996, and the floodway was inadequate, and though it alleviated to some extent, it forced them to expand the floodway.
Figure 4
There is a reason government provide flood insurance in the US. Private insurance companies won’t get involved because living in flood prone areas is asking for trouble, a self-inflicted wound, and governments often create or aggravate the problems by such actions as changing the surface.
In climate, most are aware of the urban heat island effect (UHIE), but that tends to focus on the temperature. An important cause of the temperature change is the changed surface and altered rates of runoff and evaporation.
The greatest surface changes are in the city center: an area called the Central Business District (CBD) with almost 100% impervious surface. Even the suburbs are at least 50 percent impervious surface. Figure 5 shows an average suburban lot and impervious surfaces.
Figure 5: Average suburban lot and impervious surfaces
Extensive drainage systems are designed to carry water away quickly. The water stays around in the countryside and evaporates slowly or is used by plants and transpired slowly, both processes creating cooling.
Figure 6. Rates of Runoff Urban/Rural
Figure 6 shows how these changes alter the peak at which the water reaches the river channel. The channel develops to accommodate a certain runoff rate so when water arrives too quickly flooding potential is increased.
Most rivers flood. The channels they create are for average natural flow, but if precipitation increases the channel will fill. The first stage is “bank full” when water reaches the top of the banks. Once water flows over the bank, it is in “first flood stage” and covers an area called the first flood plain. (Figure 7)
Figure 7: Thalweg is deepest part of a channel. Levees form from silt deposited during flooding.
Nobody should be allowed to build in that floodplain. Dikes to contain the river should not be allowed either because when breached catastrophic flooding occurs. Also, they prolong the flood because they prevent water returning to the river.
It is an event that occurs naturally in the old age stage of river development as a broad flat floodplain develops. Once the first flood stage occurs, water flowing along the edges of the river is slowed, and sediment is deposited creating levees. They deflect small tributaries from entering the river, so they flow parallel in a distinctive pattern known as a yazoo stream (Figure 8).
The precipitation patterns over long periods change much more than anything measured in the modern instrumental record. There is no need to build in the areas flooded shown in the following pictures of Calgary (9) and High River (10) Alberta, and Tewkesbury (11), UK.
Figure 10
Figure 11 shows the church builders knew long ago where the dry, as well as the moral high ground was located. Now with our faith in engineering, we are more arrogant and think we can ignore the long term patterns of nature. So, we need a new song, “Don’t live in the floodplain darling”.
Convert those floodplain areas within all cities, especially in the centers. They need more parks to give people access to nature, ameliorate the impact of the UHIE, and save the costs of dealing with the loss of lives and damage to property that floods inevitably bring. It doesn’t matter if the record is inadequate or if you only built for a 100-year flood to save money. When the 100-year event aggravated by changes to the urban area or the inevitable 400-year event occurs, it overwhelms and traps people who don’t understand recurrence frequencies. You can use the floodplain, but only with the ability to let nature use it for its designed purpose when she chooses.
It is known be a few names the return period, recurrence interval, repeat interval, or expected frequency. It is defined by ??
Should that be….” It is known by a few names ” ??
I remember hearing of at least one town in Illinois, I think, that was moved, lock, stock, and barrel, off a flood plain to higher ground a while back.
Well the whole city of Valdez Alaska was wiped out by the 1964 earthquake and tsunami, where a lot of the land just sloughed off into the gulf of Alaska, in a big underwater landslide; the beach just went out to sea, so to speak. A 9.x I seem to recall.
They burned down whatever remained of the city buildings and houses, and moved the whole damn town a few miles to a piece of land that the geologists said was actually somewhat stable. The entire first city land was basically geological mush.
You can actually (or you could) drive through some of the roads of the old city. It’s a beautiful region; but not for building on.
Such disasters are being supplanted with a much more selective breeding process; with events like dummies walking off cliffs while playing with their finger toys; or walking under moving trains.
Some guy Darwin, wrote a whole book about such things.
g
In figure 6, did you really mean ” STEAM ” , or should it be ” STREAM ” along the top and side ??
I live in Calgary and was here for the flood.
A few years back we went house hunting, some of the houses had the appliances in the basement fixed to the ceiling. When I asked about it the answer was “this is a flood plain, in the ‘remote’ case there is a flood, this will prevent them from ‘potential’ damage”.
We left immediately after.
I mean, who in their right mind buys in a flood plain? And then blames the government and ask for help when it floods because the insurance doesn’t cover it?
It is funny when people’d idiocy blames Climate Change.
farmers used to routinely build their houses and barns on the hill-side and leave the river bottom for crops. during winter the livestock grazed the river bottom, which is the warmest location. In the spring the livestock were moved up the hillside ahead of the floods, and the croplands got a new layer of topsoil during the flood. farmhouses on the hill were never lost to floods.
then the bottom land was bought up for city development.
That is quite interesting… also the fact that farmers were smarter than city politicians (bet the cows too 😉 )
Thanks
Flood plains generate a huge amount of tax money but only when they are developed. Governments should be required to put every dollar of that tax into insuring those developments against catastrophic flooding. If that were the law then the governments would disallow those developments. Developing flood plains is a positive forcing for creating governmental greed.
Because governments do allow those plains to be developed and because they are not required to insure those developments using tax dollars, they go after the tax base to fund disaster recovery, reaching well out of the zone of ignorance to touch the ear of the federal sow headed by the president who, with great heroism, assigns more tax payer dollars in the form of disaster relief funds.
In disconsolate circles outside the Washington DC beltway we call this a scam, a sham, and government waste. But at least we’re not confused as to why these flood plains are developed. Because modern governments believe they exist to address human suffering, these plains are an asset. There is no real down side.
In 1927, the Mississippi flooded for over 500 miles, displacing hundreds of thousands. Oops, can’t talk about that, it was before Death by CO2!
I live in Calgary and was here for the flood.
A few years back we went house hunting, some of the houses had the appliances in the basement fixed to the ceiling. When I asked about it the answer was “this is a flood plain, in the ‘remote’ case there is a flood, this will prevent them from ‘potential’ damage”.
We left immediately after.
I mean, who in their right mind buys in a flood plain? And then blames the government and ask for help when it floods because the insurance doesn’t cover it?
It is funny when people’s idiocy blames Climate Change.
I also live in Calgary. I live up in the North where it can’t flood. But yet my home insurance has gone up by 400% since then. That pisses me off!
Minot, ND floods because the Souris River, which starts up in Canada, loops down into the U.S. at Minot, then heads back up into Canada. The stateside section often thaws before the downstream Canadian portion, and the water can’t drain because of the downstream ice.
So why do Minoters live down in the valley and risk flooding? Because it’s warmer and a lot less windy than atop the hill.
The only problem is sunk cost. The city is already in the floodplain, and someone would have to pay the current residents to move. A Fifth Amendment probem in the US, as it woujld count as a “public use”.
Just don’t rebuild after a flood !!
It was proposed here. People freaked out
Francisco:
Yeah – and about 20 years ago the Alberta government developed a “Flood Plain Map” for the City of Calgary but angry residents and a host of others protested making it a “working document” because it would affect the availability of insurance so the document was quietly left at the working paper stage. However it is still available on the Internet. Surprising that the Insurance Companies haven’t reacted but perhaps there is too much income from policies to worry about a 1 in 100 event that will probably have government backing anyway (and of course it did), Downtown Calgary is built on a gravel bar at the confluence of two rivers. Who’d a thunk that wud be a problum? (sic)
Of course that is common. The City I grew up in was flooded three times before I turned 20, the last time before major dams were built on the Columbia River for flood control and hydro power through the US/Canada Columbia River Treaty.
Well, after the flood, the costs certainly are “sunked”
Just stop insuring the structures.
I’m sure that insurance companies would like nothing better than to deny coverage where there is risk and collect cash for coverage where next-to-none – what a brilliant revenue plan. But most of us live in IN THE REAL WORLD (“I’ve seen fire, I’ve seen rain”). I expect that the odds of a house burning down or having a serious car crash are probably much higher for most people in most places on any given day than the odds of being wiped-out by a 25-year, 100-year, or 500-year flood event, a tsunami, a lahar, or a landslide – even in “prone” areas. The cost of moving the vast majority of the world’s population to “completely safe” places (to the extent that those exist) seems absurd. Let’s see – move Pittsburgh PA? Manhattan? Hong Kong? London? Sydney? Vancouver BC? Most of Florida? While I wouldn’t want to build on a river bank/likely future meander, or a cliff, if people want to do that and pay into appropriately priced/sized risk pools to recover losses – fine. Nobody should be forced to “subsidize stupid”; low-risk property owners shouldn’t be bled to cover fools and scams. Risk pools and programs like FEMA should be informed by really good science, then be transparent and fair. Let the free market sort out the rest.
When you think about it, It is absolutely silly for the engineered levees of a river to be at the same height on both banks. Equitable, maybe, but totally silly.
Pick a side of the river you want to flood least. Raise the levees on that side. And raise the property taxes levees with them. Lower the property tax levies on the lower levee banks.
if the land is restricted to farming, no one really cares if it floods. the flood will bring in new soil, ready for the summer crops.
Unfortunately, in this day and age, it will also bring a toxic soup of chemicals, whether agricultural or industrial from up the river.
Raising the levees just determines how deep a swimming pool you will have after the flood. Take N’Orlins for example.
Hurricanes go up to 50,000 feet or so, so they are going to go right over your levees and fill up your swimming pool.
And building a lake on the other side to come in after the levees are undercut, and break, is another modern City engineering marvel.
Oh I forgot; the French did it originally; N.O. that is, and it’s a big nono !
G
My house is just outside the high water boundary of the largest lake west of the Mississippi river; called Tulare Lake, in Tulare County in California’s central valley. So I have to have ” flood insurance “. My mortgage company requires it, and now in this age of government mandated “you must buy this product” freedom, FEMA requires it. And they sell me the insurance too. A great scheme, invented by Emperor Obama.
What do you mean, you’ve never heard of Tulare Lake ?? You can’t miss it.
The entire Lemoore Naval Air Station, and the city of Hanford California are right in the middle of Tulare Lake.
The water of Tulare lake is probably now about 10,000 feet deep or even deeper, because all that water is now out in the Pacific Ocean; probably in Monterey Bay, in the Monterey canyon.
They drained it all down the San Joachin River into San Francisco Bay about 100 years ago; a sort of hundred year unflood project. Well somebody discovered you could grow feed corn and cotton on the bottom of Tulare Lake, If you just got rid of the water; so they did that so they could put the largest Naval Air Station in California on the bottom of that Lake.
But MY house is outside the high water boundary, and it is built on a four foot high stone and concrete wall.
Also the entire central valley of California has been laser leveled, so you can flood the entire region with just one inch of water. But that would take more water than ever falls on California in a hundred years.
There is another reason not to worry too much.
Scientists at Fresno State University, regularly test the soil in the central valley trying to detect traces of H2O. When H2O is identified on the central valley floor, somebody lays claim to it, and they run it into a huge canal and run it down to grow desert pupfish around the goof courses in Southern California.
If any of that stuff falls on my land, well I have a moat goes around my land to drain the precipitation off and into the central valley canal system. So it never gets really wet on top of my bridge across the moat.
This year, I am also going to buy earthquake insurance, since my land is on the North American Plate, where the Sierra Nevada mountains grow. I think it’s about 70 miles ‘right over there ‘ to the west where Parkfield CA is, and you can stand with one foot on the NA plate, and the other on the Pacific plate, and feel the San Andreas fault slip sliding under your legs.
Actually, I’m more worried about that Monkey puzzle tree that is slowly turning my house over by growing up under the rock wall, and lifting it. So I have to engineer a bridge over the roots, to let that tree grow for another hundred years or so. I’ll also have to enlarge the scallop out of the roof for the tree trunk to pass through.
g
I was just thinking about that this morning. I grew up under the glacier in Wisconsin and am now living under the ocean in the Powder River Basin.
Thanks Dr. Tim, nicely done.
I would add, based upon recent flooding issues experienced in Detroit, but not across the river in Canada, proper drainage maintenance is required also. Let alone the flooding in the UK attributed to not dredging when needed from silt build up in their rivers.
Budget shortfalls and eco-activism can contribute to flooding too.
if you don’t dredge the river it will silt up until the bottom of the river is level with the tops of the levees. if you haven’t built the levees higher by then, you will get a flood.
as in most things in life, you get a choice of 3. dredge, higher levees, or floods.
Only in the slower lower sections of the river.
As long as the river is fast running, the silt will wash down the river till it hits slower water.
It’s one of the reasons that dams silt up so fast as they’re often built where the water normally runs fast down from higher elevations. Build a dam where water is forced to stop and the silt settles out reducing the dams water holding capacity.
Lower river and especially estuarine rivers form that snaky path. Rivers like the Mississippi river fill up with silt until during a flooding event they cut their banks and form a fresh new river channel.
The old channels left behind form oxbows.
Many of the bayous around southern Louisiana, Mississippi and eastern Texas are frequently formed when a river or local stream floods and builds up the delta. When the water recedes, the water flows quickly cut new channels, though it can be very difficult to tell a main channel from older ones.
It is also very easy to get lost in the bayous, and quite unpleasant jumping overboard in confirmed alligator territory to push boats out whatever muck stopped the boat and plugged the motor. One needs to clear motor cooling passages with water or really get stuck in back in the bayous. Lots of fun!
Not that this changes anything said above, as that is all accurate. I added a few quibbling details to a quite complex subject.
Like building your house under an approach or departure to a runway and complain about the noise or at the beach subject to tropical cyclones.
It seems there are are a lot of 100 yr and 500 yr floods that now occur at regular intervals leaving people wondering why their homes are submerged every 15 years. Maybe they need to revisit what is possible.
I will say here in Raleigh NC they have done a pretty good job of restricting growth or requiring homes on marginal floodplain lots to be built on stilts or infill. Then they approve a large hard-surfaced shopping center upstream and after a hurricane or extremely heavy thunderstorm, cars are submerged and first floors of homes in the effected areas since the runoff happens so quickly.
I have a number of huge white oaks that can flatten my house. Should I cut them all down on the anticipation? This is a good question, but maybe the answers aren’t as easy.
Cut them down and replace them/ Do not do all this at the same time; keep your fingers crossed.
People often claim that they were flooded out by a 100-year event when they weren’t. It’s just wishful thinking and an excuse by lazy/cheap city planners. It was too expensive to build for a 100-year event, they only built for a 10-year event. After all, who is going to be able to tell the difference?
…”requiring homes on marginal floodplain lots to be built on stilts or infill.”
Adding fill to a floodplain displaces an equal amount of water and thereby increases the flood elsewhere. It doesn’t matter whether the fill is residential, retail or municipal infrastructure.
I lived near the Shenandoah River in Virginia as a wee lad. Floods were regular occurrences, at least every 5-7 years. The same people would just re-build in the same places after each flood. Seemed pretty silly to me then and now. My dad built our house up on the hill overlooking these riverfront properties, probably 200m higher. Needless to say we never even got close to getting flooded out, but it sure was fun walking down to the river to fish (Actually I would mostly stick to pond and lake fishing; I preferred bass over trout or catfish).
I now live in Western Washington, on Whidbey Island. But I work in Mount Vernon, in the Skagit Valley, which is one big flood plain. Of course they’ve built levees. Most of the valley is farmland, the tulips are world famous. But there are still a fair number of residential areas that have probably flooded before, and will again. The levees will only make the flooding worse down or upstream where there are none.
Huge?
White oaks? Definitely not red oak or chestnut oak or post oaks?
I doubt you need to worry. White oaks are not known for just falling over, even in clay soils. Red oaks may do that all of the time, but not white oaks. In Raleigh, you might even have live oaks around, recognizable by the huge branches that run parallel to the ground.
Now if a hurricane wanders near or a tornado, well those weather events can change an oaks mind.
I live on a well drained hillside 700 feet above sea level in Kailua-Kona, Hawaii. There is very little risk of flooding or land slides. One minor complication is that my house is on the slope of an active volcano which erupts on average, every two hundred to three hundred years, and last erupted in 1801. No location on earth is risk free. If you can insure against a risk, fine; otherwise, be prepared to assume the risk yourself and hope for the best. I don’t believe it is the proper function of government to protect people from the risks that they willingly take upon themselves.
Similar arguments could be made against living in earthquake zones. ‘You can use the [tectonic zone], but only with the ability to let nature use it for its designed purpose when she chooses.‘ Or the tornado zone. Or the hurricane zone. Or the volcano zone. Or the malaria and tsetse fly zones, for that matter.
Everywhere has its existential natural hazards. We can’t avoid building near them and living with them. We just need to engineer our lives and infrastructure to deal with them.
If living near some river requires dikes or diversion channels, then so be it. If we don’t pay attention to their maintenance, then the fault is ours when disaster happens.
The eradication of the screw worm from the Western US and Central America is a fine example of the engineering fix. It works but it needs constant attention. One wonders if such a project would even be possible today, given the sacralized natural environment. Headline: Driven from its natural range by human meddling, the screw worm fly is now endangered. It’s not too impossible to believe, is it.
Is the term ”Screw worm” a a politically correct term for a Liberal in the US?
Depends.
Is screw a noun, verb or adjective?
The major flood in Winnipeg was in 1997, not 1996.
https://en.wikipedia.org/wiki/1997_Red_River_Flood
That was during the winter of 1996/97. That was the year of the semi biblical rain event in Northern California and Southern Oregon mainly. Good snows had come early to the mountains of Northern California. All the ski resorts were looking forward to a great season. Then around December a warm rain came in. It then rained for around 30 days and nights. The warm rain started melting all of that snow, and much flooding followed all through the upper Sacramento Valley. Lakes were forming. That was during a La Nina event and also at the time close to the solar minimum.
This link:-
http://www.chroniclelive.co.uk/news/north-east-news/flooding-cause-government-would-keep-10580092
did the rounds here in the UK last December. Dellingpole and Booker picked up on it but the MSM preferred to blame “climate change” for the flooding events that conveniently were occurring during COP21.
In the most egregious example of poorly chosen suburban development California built “Silicone Valley” right o top of 200 FEET of topsoil that had made that portion of California Agriculture one of the most productive in the world. As population grew, urbanization spread to the Central Valley in an additional waste of prime deep topsoil superior in every way to other locations in the world of agriculture. For a period California was by itself the 2nd largest producer of rice in the World and a provider of something like 75% of all “table crops” grown in the United States. All because those valleys are the result of millennia long deposits of flood plain silt. Truth is that San Francisco and LA are built right where they should be. It’s the sprawl that wasn’t thought through very well.
Silicone Valley refers to Hollywood cleavage. The place where all the start-ups and venture capitalists roam is Silicon Valley. The element, not the implant.
well pat, at my age I sometimes lose the battle with spell check
“well pat, at my age I sometimes lose the battle with spell check”
And cleavage, apparently 😉
Determining the true regularity of rare events is, statistically speaking, a very difficult problem. You are dealing with the tails of probability density functions, and this is a scary thing to deal with as the type of distribution can only be guessed at (is it Gaussian? Cauchy? How thick is that tail?)
In other words, estimates of “100 year events” should be viewed skeptically.
Is this flood 1993 Mississippi River consider a 100 year event. I was flying from Montreal to LAX at that time. The pilot tip his wing both left then right. Both sides of the plane had a perfect view of what now looked like one of the great lakes. http://mo.water.usgs.gov/Reports/1993-Flood/
Tim. This is proof positive of Co2 induced climate change, a study grant should be given without delay to prove that flood plains, barrier islands and reclaimed coastal areas prone settlement have only flooded since Co2 increased above 280ppm. lol
n my city, the local council is setting up to move people from what they call an “Inundation” area which is the area of the city that will be unlivable when the sea level rises to 1 metre in 2115. Based on an exaggeration of the IPCC’s predictions of sea level rise. The catch is that there is no sea level rise acceleration recorded as yet but unfortunately as most of the people in the affected area have swallowed the global warming hype, they cannot argue against the facts””.
It looks to me that the council will get away with it and these people’s property values will erode steadily to nil within the next few years. Values have already taken a big initial hit in this zone.
My take on it is that this is an Agenda 21 initiative, and the council is returning these “wetlands” to their “natural state” and getting away with it.
https://www.facebook.com/n/?groups%2Fccrugroup
I think the above link will take you to the general discussion on face book.
Agenda 21 in my city is described to some extent by my blog.
Cheers
Roger
http://www.thedemiseofchristchurch.com
“Inundation” area
=============
sounds like a great way to get your property taxes reduced. pickup some waterfront for a steal.
so why not simply jack the houses up and fill underneath if and when the water comes in? Surely 1 meter of fill is a whole lot cheaper than needlessly tearing down neighborhoods.
Hell, when I first moved in, my back yard was the lowest property in the neighborhood. I advertised “free fill wanted”. Truck after truck came by from local excavation sites and dumped their loads in my backyard for free, rather than haul to a remote dumpsite.
I raised my backyard 1+ feet for the cost of the rent of a bobcat for the day to level it, and now when the “monsoon” rains come in the winter, the yards on either side flood, while I’m high and dry. Like swimming in shark infested waters. You don’t need to swim faster than the shark, only faster than your buddy.
LOL
In most US jurisdictions, what you did is illegal. Local ordinances usually forbid you to alter the drainage on your property so that it increases flooding on your neighbors’ property. Usually gets you a civil suit as well.
The particular IPCC prediction that was factored into the Queensland state planning policy runs as follows. Average temperature rise 3°C by 2100. For each degree, there will be a 5% increase in precipitation, so 15%. Apart from a few hills, the whole urban region I live in is pretty much coloured blue, and now includes areas that did not flood in a 200 year event in 1998, or in another 200 year event that occurred in 2000.
The recent Brisbane floods were claimed to be the worst on record because of the damage costings. The 1970s flood was 4 feet higher but less damage because back then no one was silly enough to build on a flood plain.
I like that: two 200-year events occurring just 12 years apart. Like I said before: people making excuses for bad planning.
Bad planning, bad science, or just plain bad luck? The “best laid plans” will never be perfect. There’s no 100% reliable crystal ball. There are very nice “floating houses” being built in Holland these days. Change is the only constant. Cope 🙂
The scary thing for me is Most of the bulk food storage is along low lying land near ports. I am in Brisbane, the food here is located along a river flood plain. Massive refrigeration storage depots about 2M above sea level. Not very bright. I think this is repeated Worldwide. If you’re not a prepper you should be.
Nice sentiment. Not gonna happen because the cities already are where they are. At best, duture construction and reconstruction can be mindful. Just like in Florida, all new or repair conateuction must meet the latest hurricane codes. And hurricane insurance has been jacked up considerably. Don’t let perfect be the enemy of good enough.
Which is why our new windows are rated @180MPH.
No wonder the affordable 3 and 2 is a thing of the past.
The Sun is as quiet as a mouse, quietist for a hundred years they say. Solar wind very low, now Google “Cloud Project” and see results. These floods are going to continue for a long long time, and then the COLD.
jimheath
That’s why I trust the watermelons are a bit right – can even watermelons be 100% wrong with 100% of their output? – and we get no cooling, at least,
Cold kills.
More cold kills more.
Auto
nice article. very educational.
Build smarter. In the picture of Calgary, there are two residential towers beside the river on the left side of the picture (just left of the green oval like shape beside the river). Those towers are new and were built flood proof, which meant the under ground garage was waterproofed, the drains in the floor have flowback prevention valves, the electrical was on the 4th floor of the building, etc. Those buildings experienced no damage and only had power turned off because the city turned in off.
No back up generators on the 4th floor? I recall seeing portable generators providing power to a number of buildings in Calgary after the power was shut off because the underground system was still unuseable. I notice that Home Depot stores typically have their own back up generator on site. Yet most building developers don’t think that far ahead. Curious that Home Depot does. The one closest to me in central Alberta (100 km away) has recently upgraded their gen sets from a single large Generac to Two different units (I have forgotten the name). So not only do they have back up power, they have backup to their backup.
From what I heard, there were backup generators for computer systems in the larger companies, but not enough for full building power. As for residential, I don’t know of one buidling in Calgary that has a full backup capability.
Here developers have to provide 3 phase backup power for lift stations because water and treatment plants have back up but that one step didn’t.
where has common sense gone, felled by climate change and computer models ??
As folks have moved away from nature and into urbanity, as real education (learning and integrating actual subject matter) continues to fail, as statist bureaucrats drone on and on about how only their bigger outfits (with our earnings) can help us, people actually believe (guilt) that we are the cause of all that extra rain and snow because we favored civilization.
Well, I live on a hillside in an 1850’s post and beam farmstead originally built on a field rock foundation which allowed all that rain and snow melt to just flow on down the hill. Before the oxen hauled the stones, the farmers planned what they were building and where. I lifted the house two decades ago and poured in a concrete foundation, but also added extensive perimeter draining (flows down the hill, around the place and further down the hill). Of course the river bottoms flood in Spring – as they always have. There, it is mostly a problem for our brook and brown trout neighbors. They’ve had it figured out for a long time and didn’t need climate ‘science’ or a computer model.
Thanks again, Dr. Tim
As a retired engineer I agree totally with your analysis. You are Spot On, Dr. Ball. Thank you.
Here in Australia many people live in the bush (forest) surrounded by trees plus undergrowth and bush-fires regularly come through. No problem if you are your family survives, just go back to the same or a similar location and rebuild (to get burnt out again later). The media praises you for being heroic and also praises the fire-fighters for risking life and limb (the latter rightly so) without noticing the stupidity of these bush dwellers- or ignoring this little fact because it sells either newspapers or TV advertising time.
Interesting points are made, but every spot on this planet (even high ground) is geologically active in the long haul. Predicting rare events (100-year, 500-year) is a fool’s game. Regular occurrences like annual floods are another matter – but even in those cases, “clean up and carry on” may be the most practical policy.
Adapt, adapt, adapt – and cope with reality. Look at Holland. Look at Venice. Some very clever “floating home” designs have been developed for new structures in places with high water conditions on a regular, periodic basis.
The cost of “relocating” everyone (or denying land use) because some event MIGHT happen (like a flood or lahar event) is ridiculous. All life involves risk-taking.
Ellen,
I agree generally with your outlook, and would blend in some of RobP’s pragmatism (up-thread).
Everywhere has something going on and it doesn’t have to be geological. The social dysfunction of some scattered, remote communities, with high alcoholism and suicide stats could prompt the call to not live there. Don’t live downstream of a dam. Don’t build under a volcano, don’t live in Tornado Alley, don’t live below sea level; avoid forest fire “interface” zones.
And then, there are all the bizarre misfortunes that befall individuals, but don’t get the big headlines. I was flooded out by peripatetic beaver plugging a culvert.
Nonetheless, an interesting article from Tim Ball.
Ideally active flood plains should remain agricultural land dedicated to annual crops. Perennials and woody plants often do not do well when flooded.
Levees should be built to slow the river and maximize temporary water impoundment to increase sediment deposition on the active flood plains which enriches and renews topsoil.
The number, size, and cost of buildings on floodplains should be minimized, and they should be constructed on elevated ground (possibly the levees themselves) whenever possible.
Permanent structures, office buildings and residential buildings should be relegated to elevated terraces.
Insurance companies could drive this. In California they have chosen not to provide fire insurance to buildings with wooden shingle roofs located in high-risk areas (outside city limits), and because of the widespread risk of earthquakes in the state, building with unreinforced masonry is simply banned.
Sediments delivered by floods contribute to soil; mankind has benefited and thrived on fertile floodplains and river deltas for ages. Plans should be based on and reflect realistic first-rate local geomorphology, with practical risk/return analysis. Abandoning all shorelines and floodplains to avoid all risk seems way out of proportion.
I highly recommend the reading of “dirt – The Erosion of Civilisations” by David R, Montgomery to understand how mankind has always, it seems, braved the wrath of Mother Nature.
Relevant to this discussion is this from his Rivers of Life chapter:
Good reading explaining lots of other ways we mistreat our local environments with short-sighted thinking.
Having worked with flood and drainage districts for many years, here in western Washington state, I could not agree more with the Ball’s points. I go around telling anyone who’ll listen that urbanizing the floodplain is a universally stupid idea.
* The floodplain is the river’s hydraulic shock absorber; what is called “the river” is in fact merely its meandering, low-flow channel.
* There are only two kinds of earthen levee: those that have broken and those that will, and the higher you build them, the more catastrophic the eventual breach will be.
* Floodplains (usually farmland) are developed because the land is cheap and the short-term profits and tax revenue consequently high. But if the same local governments that permit it had to pay for the enormous cost of flood damages themselves, instead dunning the federal taxpayer, floodplain development would stop TOMORROW.
Tim Ball, a well written article on an appropriate topic. It helps in the discussion of whether to consider some flood plain people as climate refugees or should be considered just short sighted people.
I would add that one should not build a structure at the level of the flood plain or if one does then build it high up on stout stilts well above the highest (worse case) flood level. The stout stilts need very serious foundations able to withstand: a) water flow pressure; b) being hit by massive floating objects in the water flow; and c) weakening due to seepage into the ground around the stilt foundations. One would also need to make sure to have redundant diesel generators and ample fuel tanks.
John
It true that we should not be developing more properties on floodplains.
People at one time had good reason to want to live adjacent to major rivers.
But with piped supply of water and transport by road and rail, those days are gone.
HOWEVER – that doesn’t mean that we should simply abandon land and properties that have been historical effectively drained by man. And certainly not that we should abandon people in such regions to the whims of environmentalist obsessives who wish to return the built world their fantasy idyllic wilderness governed only by the forces of nature.
A recent study concluded that 9 out of 10 of the properties that flooded in Somerset, UK – did so because of inadequate drainage. i.e. that had the systems of drains and pumps been maintained as intended then the flood would have only affected an extremely small number of low lying properties.
They also concluded that this lesser flood would have been shorter in duration.
In summary, we can see that had there not been a cessation of regular dredging and maintenance then critically – their would have been NO news stories about Somerset in 2014.
And with no news story – there would have been no disaster to blame on terrifying global warming and rising sea levels.
No disaster in Somerset – would therefore have been a disaster for the eco-left.
And so their plans have worked out better than even they could have ever dreamed:
http://www.westerndailypress.co.uk/Better-pumps-dredging-stop-floods/story-27574691-detail/story.html
Very nice lecture on how rivers work and what they are there for. I filled sandbags for the 1950 flood which was a doozy. I remember with fondness the endless supply of sandwiches and coffee that women citizens delivered to the trailers at a number of spots were bagging operations were taking place.
My first engineering job was with, IIRC, the Water Control Branch of the Manitoba Department of Agriculture in the design and early construction phase of the Greater Winnipeg Floodway in 1961(2?). Dr. Ball, you probably knew a fellow by the name of Locke and another by the name of Frank Render (whom I graduated with). I believe they were at the Ministry for many years. I worked in the hydrology part of the data gathering. A prime job was, in addition to putting in wells with piezometers along the right-of-way, was to measure all the farmers’ wells within a swath on either side of the planned channel in preparation for the inevitable claims that they needed a new well because of the floodway. Actually, the farmers’ wells didn’t change noticeably and we didn’t expect them to, but when claims came in we already had their records pre and post and had with a number of them already advised them to drill a modern decently installed well that they needed with or without the floodway.
At the time, the GWF was the second largest excavation project in the world after either Suez or the Panama canal. There is no question that it was a technical and economic success, but, of course any large engineering works need maintenance and upgrading. I didn’t follow its biography much after I left Winnipeg in 1965 (I was back to complete an MSc a few years later but then gone again).
Also, in other work with the Ministry at the time, I did a groundwater exploration project in the Souris area in southwestern Manitoba (town supply and stock watering) and discovered a buried main channel of the Missouri River when over 100,000years ago, before the continental glacier covered the ground, this river actually flowed north. It was identified by the gravel being a brown quartz with petrified wood fossils and “opaline wood” – wood cells replaced with opal. It had been traced along its route through North Dakota and into Saskatchewan where they lost it when, apparently it made substantial bend. I was drilling holes to shale bedrock about 30 to 50 feet when suddenly we nearly lost the whole drill string and had to put the brakes on as it ultimately went down about 200 or more feet into the distinctive gravels and the sweetest water in Manitoba. When the glacier blocked flow northward and things froze up, the old Missouri waited until it melted and made Lake Agassiz which was bigger than all the Great Lakes put together. This major part of the Missouri then was captured by the headwaters of another south-eastward flowing tributary of the Mississippi, the modern Missouri, and the water flowed southward leaving much of the old channel buried.
I also was the guy that got sent out all over southern Manitoba to sites where farmers and municipalities planned to drill wells. It was the law that they follow certain procedures because of bad experiences with washed out artesian wells. One job was actually plugging a runaway artesian well in western Manitoba, a thing I didn’t have a clue on how to do. I took the driller (name of Tillepaugh) and his rig to see what we might do. We got there to find a sizable little lake in the hollow field where the farmer had had the hole drilled and it was centered by the ugliest swirling waters I had ever seen. I said to Tillepaugh, what in hell are we going to do with that! He hummed and hawed and then said maybe we can plug it with a telephone pole, the hole will narrow with depth. We’ll need a dozer and chains to tie on while I back the rig to the hole with the telphone pole and we’ll need a cement truck full to pour the cement in the instant we stem the flow enough. We had to time it well because the pole won’t hold it back for long and it could shoot up into the air kill us if it gets away on his. It worked like a charm with dozens of farmer spectators shaking their heads that it wouldn’t. We gerry-built a chain hook-up to the hydraulic drive for the drill stem and raised the pole up along the mast of the rig. We rammed the telephone pole down and the waters quieted and then with troughing from the cement truck, poured the whole truckload down the hole and let it set for the day. We probably left a story or two behind us.
Gee, your article tapped into some nice old memories.
🙂
Nice memories. From one Eng to another.
Actually the floodplain is as much a part of the river as the channel. It’s just a part that may not be in use at any particular time.
“Nobody should be allowed to build in that floodplain. Dikes to contain the river should not be allowed either because when breached catastrophic flooding occurs.” Nailed it – but who listens when land use is a political matter given that land in non Green Belt areas is in short supply, as it is in most developed nations.
BTW: The EU banned dredging (which had been mandated for centuries as a flood control requirement in certain locations) as a means of flood control. With the Cumbria floods, guess what contributed the most to their massive flooding problem? With the best of intentions and all that…..unintended consequence.
Actually they didn’t ban it, they just required that the dredged silt be treated almost like hazardous waste and not be used for embankments or for dumping at sea unless so treated. But it had the same effect as banning.
The Rio Grande in Albuquerque New Mexico is instructive
When white settlers arrived, the river had natural levees that would breach from time to time in high discharge floods. Bottom land near the river (floodplain) was mostly used for pasturage. Over time, the city center developed and spread into floodplain lands
Following major flooding and damage in the 1940s, the U.S. Corps of Engineers channelized the river within permanent levees, and the river silted-up its channel (no longer able to discharge excess silt over the levee tops). The river bottom actually became higher than the elevation of bottom lands outside the levees, and the bottom lands became waterlogged. So the USCOE built drainage ditches to drain the bottom lands, which allowed for residential and commercial development back in the drained lands.
The artificial floodplain contained by the artificial levees is now overgrown by cottonwoods, willows, and invasive water-loving trees and shrubs (tamarisk, mesquite, salt cedar, and others). The tree-hugging locals lovingly refer to this as the “Ancient Bosque Forest”, clueless to the fact that it did not exist prior to 1940. More ironic, the City of Albuquerque has to pump groundwater for municipal supply because the surface flow to the Rio Grande was completely “appropriated” before any significant population existed in the area – appropriated by farmers downstream in the Elephant Butte-El Paso region. The Bosque “forest” today consumes at least 25% of the stream flow by evapotranspiration, which is lost to both the city and the downstream farmers.
This fabulous mess was brought to you by the Federal Government, using your tax dollars to solve problems that were created by government mis-management – – and by local foolish uses of floodplains.
You ‘d think that a town named High River would be a clue not to move there. High River, Alberta, was flooded in 2013 because of a … wait for it … high river!
High River, like many Cities and Towns along waterways, grew without benefit of planning or engineering. It originally was a low spot in the river bank with a good gravel bottom that allowed fording of the river when it was low. An enterprising group built a ferry to take people and goods across the river at higher flows with a house for the ferry folks. Gradually a community grew up around the ferry and became High River. Parts of the City has flooded many times. During the last flood, one of the worst hit areas was behind a dyke, once flooded, the water couldn’t get out again.
Very good article. I am still reading, but two immediate points.
Fig 7 looks very much like the southern shore of the Ottawa river.
Fig 8 reminds me of the source of the phrase “Up the Yazoo”.
You can build in a flood plain, provided you build on a barge.
http://www.motherearthnews.com/nature-and-environment/unsinkable-shelter-on-a-barge-zmaz82jazgoe.aspx
I’ve been alive long enough to have learned, through experience, that 100 year floods happen every 20 – 25 years. Yeah, they’re not supposed to, but they do. They always do.
A 100 year flood is meant to be a once-in-a-lifetime event If they are now coming at 25 year intervals, it’s a once-in-a career event for hydrologists – which is much the same thing…
Very good article, Dr. Ball. Three items to consider:
FEMA and other US agencies also use “annual exceedence probability”. For example,
http://pubs.usgs.gov/gip/106/pdf/100-year-flood-handout-042610.pdf
The word that describes the (lack of) change in the long-term hydrologic record is “stationarity”. The stationarity tar pit is wide, deep, but very inviting.
https://www.researchgate.net/publication/268283405_Modeling_and_Mitigating_Natural_Hazards_Stationarity_is_Immortal
The tar pit includes hydrologic statistics. For a start, there is the adopted methodology for estimating the “100 year” event using log Pearson III statistics:
http://acwi.gov/hydrology/Frequency/B17bFAQ.html
http://water.usgs.gov/osw/bulletin17b/bulletin_17B.html
Professor Leopold, one of the fathers of limnology, taught me that the 10-year flood plain was the level that flood two or three time in 10 years. A 100-year flood plain floods two or three time in 100 years. In Wheeling, West Virginia the is Wheeling Island, the site of many homes, businesses, a football stadium, and a large casino. The island floods quite often, which is logical since the island was built by floods that deposited all of that mass. This means floods much higher than the island on a regular basis.
Hey this looks like a great place to build a settlement. What do the natives call it? “High River”. I wonder why? Looks just like a little creek to me. 100+ years later we are still building and living there.
Silly Earthlings (Marvin the Martian)
After seeing the City of New Orleans rebuilt in place after being all but destroyed in many areas, I have little hope that you warnings will be heeded, Dr. Ball.
After all, if people are too stupid to move a wrecked city to a new locale after being wrecked, even when the city is below sea level and sinking further every day, even when the city is in the most hurricane prone stretch of coastline on the entire continent, and perhaps the entire world, and even when the city is astride one of the largest rivers in the world, which is higher even that the sea that it also sits below.
Yes, people are way too stupid to take good advice, even when they just witnessed firsthand a small taste of the disaster that can be expected to reoccur on a regular basis.
How timely. Today’s LA Times….a bastion of AGW hype….had an article on “our country’s first Climate change refugees” from Newtok, Alaska, a small (350 people) village on the banks of a river. It goes on lamenting how federal assistance is slow helping these people move to safer, higher ground. “To truly make a lasting client change legacy, Obama must take seriously the issue of climate relocation”. The real issue is the same anyplace you have moving water next to land…..erosion. The village has already relocated from its’ first location due to erosion and now it must move again. The article gave an image of townspeople wallowing in melted permafrost during the melt season due to “Climate Change”. It also says we should be making plans for “thousands more from along America’s most fragile shorelines will embark on a great migration inland as their homes disappear beneath the water’s surface.” Reality should be catching up with and surpassing the hype soon.
Great. Another reason for lefties to employ to encourage the use of the force of government to tell people were they can and can not live. Its bad enough that lefties are working diligently to force people into high density housing.
Again – I think a lot of folks need to curb their “inner Chicken Little” and put this risk into perspective. Adapt, find solutions, dredge if need be, keep moving. I’m in my mid-sixties and I’m originally from Pittsburgh PA (now living in western Washington State). I was raised listening to first-hand accounts of the Pittsburgh Flood of 1936 and the Johnstown Flood of 1937; scars remained on the landscape and landmark buildings. There was also extensive flooding in the U.S. east in 1951. All regions and places experience severe events: floods, hurricanes, tornadoes along with tsunamis, earthquakes and volcanoes. Such is life. I worry that our young have become so obsessed with perfect-planet theory (“sustainability”) that plans have become cripplingly and foolishly risk averse.
2011 floods in Brisbane, Australia.
http://www.abc.net.au/news/specials/qld-floods/
‘Aren’t we lucky to have water views from our backyards?’
Known flood levels in the same area since the early 1850’s:
http://www.bom.gov.au/qld/flood/fld_history/brisbane_history.shtml
From the Brisbane City Council’s web site:
Even when an area is a known flood plain, they still build on it then scream when a flood occurs (plus blame AGW as well).
The fools that call them drongos are no idiots (an Australianism)
We may also reach this logical town planning through socio-cultural processes, just like that picture of Tewkbury church on a slight rise. The last time I bought a house I said (loudly) don’t show me anything in a Watermeadow Drive or a Riverside Walk. And the guy next to me laughed, and said ‘I said much the same thing’. The message is getting out there, that riverside properties are problematic to live in, impossible to insure, and difficult to sell. (Unless builders do the sensible thing, and build these properties on stilts, with the car port under the house.)
R
It is hard to control floods in the plains.
Better to do it in the higher grounds.
An excellent read for flooding/flood management:
http://www.amazon.com/Rising-Tide-Mississippi-Changed-America/dp/0684840022/ref=sr_1_sc_1?ie=UTF8&qid=1453812200&sr=8-1-spell&keywords=missiippi+flooding+1927
The 1/100 event planning does not mean that there will be only 1 such event every 100 years or that such events will be 100 years apart.
It was an estimate based presumably on data thought to be pertinent at the time.
The Victorian London sewers were designed to cope with .5″ rainfall in 24hrs. A generous overestimate at the time.
Urban growth and a penchant for paving over driveways and gardens have scotched that, even within the core area.
As for the 1/100…………..lol
My house lies in a designated flood plane, so this article is of some interest to me. There are several important points to make. First, the Red River of the North and its tributaries flow north. They flow from where it’s warmest, to Hudson Bay, where it’s a lot colder. This causes spring ice jams, making flooding more frequent than in most of the US where rivers flow from cold to warm. Second, I choose to live where I live. I enjoy being close to the water. I accept the risk. I made my basement floor a bit higher than the last large flood. It was in 1954, before several flood control dams were built. (I note that flood control dams don’t prevent floods – they create them. Hopefully they move the floods to more suitable locations. I’m in such a ‘suitable’ location, though the dam would be overflowing long before I would get my feet wet.) I constructed the lowest wooden parts of the house to be 8 feet above the designated hundred year flood level. I don’t keep anything in the basement that I can’t afford to lose. I don’t waste my money on flood insurance. Finally, in order to build the house, I needed permits from FEMA, Corps of Engineers, the state DNR, County, and Township officials. it took more time to get the permits than it took to build the house. I don’t need more people than that telling me where I can, and can’t live. I should also note that in the winter I live along the Guadalupe, in what some call the most flood prone area in the US. Last spring, a nearby location went from a normal river level of 5 feet, to a flooded level of 34 feet, all between 10:00 PM and midnight. I chose to be some 370 feet above that.
You must be part of the 0.1%. People with brains that use them.
As a wee lad sitting at my great uncle’s knee during a visit to his Central Texas ranch I learned some important lessons. (Summarized and edited for clarity and a “G” rating)
1) Build high. It doesn’t take a Ph.D. to determine the extent of the worst flood the soil and flora indicate.
2) Build the house and the barn on the sorriest, least productive soil on the property rather than the best view. That leaves the rest for producing your food and fiber. Further explanation provided was that this same soil is probably eroded of the topsoil, well draining, and well oxidized (stable), but may be corrosive to steel.
3) Dig to the rock (if present) before pouring the slab, then it really won’t crack. (nice metaphorical reference too).
4) Don’t buy/build where there is not good water available via a drilled well or surface supplied by springs which may be stabilized/protected or perrennial streams.
Wisdom from the poorly educated, but supremely intelligent.
Many years later sitting in “Soils”, “Forest Soils”, “Range Management”, etc. the simple lessons of my uncle remain the most basic and applicable. The undergrad and grad level classes just gives the why and how the obvious to the observant is.
The State of Texas is making some moves in this direction. So is my present state of residence, Louisiana. After you’ve flooded out once = no more insurance for flooding. An area may still be developed, but the developers are bidden by law (for what it’s worth) to disclose past flooding and the fact that flood insurance is unavailable for the zone.
So there are some good policies coming into play which should discourage development of flood prone areas.
…Flooding And Planning: We Don’t Need To Live Near Rivers Anymore…
Actually, we do. That’s where all the transport links have been built.
Here is a fascinating bit of research that should be of interest to anyone wanting to learn about pre-historic mega-flood events along the Mississippi River in North America. It looks like some pretty solid work, although they use the pages 2k temp reconstruction, presumably because the authors believe it’s the best available for the continent. The sediments were radiocarbon dated. I suppose one can’t compare these prehistoric flood events to modern day Mississippi River flood levels due to the fact that the entire watershed has been altered so much (levees, dredging, dams, etc) by the Army Corps of Engineers to mitigate flooding since the 1930’s.
http://www.pnas.org/content/112/20/6319.full?sid=86fd14fe-f84b-4eab-ae92-5d106148a74c
The Missouri River carries a lot of grain. As does the Mississippi.
Planning has become a euphemism with a genocidal connotation.
Ditto. As critical areas ordinances are expanded in our area, land use is being denied. There’s no sufficiently “safe” or “sustainable” place for humans to inhabit. FEMA and the Corps of Engineers are working hand in glove with environmental groups to “restore” our area to pre-industrial conditions, as if there is some perfect state of affairs. The local college’s environmental school teaches that “there is nothing more natural than nature,” whatever that means when it’s at home. (All human actions and impacts are unnatural. Surprise!)
Once the first flood stage occurs, water flowing along the edges of the river is slowed, and sediment is deposited creating levees. They deflect small tributaries from entering the river, so they flow parallel in a distinctive pattern known as a yazoo stream (Figure 8).
From several studies done by the Wyoming Game and Fish Department, I would guess that the wide flat floodplains along most creeks, streams, and small rivers in most of the U.S. were originally developed by the beaver. According to the Wyoming Wetlands Society:
“Prior to European settlement, beaver were found in high densities throughout North America, but were nearly exterminated by 1900 to meet the demands of European fashion (primarily for felt hats). Populations before European settlement are estimated to have been as high as 600 million, occupying nearly every watershed in North America from northern Alaska to central Mexico.”
It’s only after we eliminated the beaver from most watersheds that sediment levees and yazoo streams had much of an impact on river flow. Eliminating the beaver has probably had more effect on local climate than deforestation.
Flood plain residents are as crazy as ocean cliff dwellers.
This is at Pacifica, California where the San Andreas fault meets the Pacific Ocean. That should count for two entries on the stupid list.
And to the northeast of you, across that expensive channel, the maxim should be “Don’t live in the Delta, daryling.”
http://www.canada.com/vancouversun/story.html?id=00c485c3-108e-414c-8443-d1511ece692d&k=27525
Which is a flood plain, maps made by early ship visitors using telescopes show many small low islands where many people live and work in Richmond, YVR on the smaller Sea Island, (The Fraser River forks in the area, a main fork on the south side of Lulu Island, another on the north side – which itself forks around Sea Island.)
Mostly diked today, pumps have been beefed up since I walked on the west dike decades ago and noticed not much margin as winter winds pushed high December tides against the dike.
If an area of land is called a FLOOD PLAIN, why are people so surprised that it occasionally subject to flooding?