Say from the Mississippi to San Diego?
When the snow melts every spring towns along the Mississippi are inundated with water that just flows into the Gulf of Mexico anyway.
What a great stimulus the building of it would be for the economy and it would actually benefit the whole country.
Well, there are the Rocky Mountains, for one thing. And it would be hard to pipe the water more than a few miles from the main canal.
Just a few, off the top of my head:
The bottom of the canal would have to have sufficient slope to get from the Mississippi to the west coast. I’m not sure we have that.
The canal would have to either be cut through the Rockies, or pumped over them. I don’t think it’s feasible to do either one.
Every stream which this canal crossed would have to be diverted over or under the canal. Think of what that might mean for large rivers, especially considering how wide they are at flood stage.
Disruption of barge traffic on the Mississippi - there is such a thing as minimum flow in a river; without this minimum flow, the barges wouldn’t be able to operate. There goes a huge chunk of commerce.
Evaporation - losses can be as much as a foot of water per day. How to get the water across the desert without losing all of it to evaporation?
This would be some serious terraforming. Much, much too expensive for the United States to undertake.
It would be a logistical nightmare for several reasons. The southwest is several thousand feet higher in altitue than the Mississippi river valley. You’d have to blast through a couple thousand of feet of bedrock. The agricultural industry of the midwest depends on the mississippi river’s waters, as well as the barges that transport goods and raw materials up & down the river. The canal would be thousands of miles long and would probably take years to dig. Being thousands of miles long, most of the water it transports would evaporate. You would have to pump any water you use a half mile vertically to the ground surface. I don’t think what little water you could bring from the mississippi to Arizona would offset the cost of digging such a canal.
I thought of something else - maintenance. The states which the canal goes through are not going to want to spend their money on it - why should they, when it doesn’t benefit them? And California’s broke.
I was just reading about projects like these.
The answer always seems to be people are afraid of what might happen. I was just reading a book about diverting the Ob and other rivers that flow into the Arctic Ocean. A lot of them revolve around putting it into the Aral Sea which is a total mess.
While it should be do-able and not hard, no one knows the effect of the diversion on the Arctic. Half the scientist says it would increase ice, half of them seem to think it would make the water saltier and decrease the ice in the arctic. So you may be solving one problem by creating another. And the Aral Sea is a mess because of the rivers being diverted for cotton.
Other plans like restoring Lake Tchad seem on the surface rather easy but who knows what would happen.
Take a look at the Colorado River, it was damed up and provides life for Las Vegas, Phoenix and Los Angeles, among others. This seems ideal till you realize Los Angeles and the surrounding area can only support three to five million people without bringing in water. That is in the AREA not the city. LA itself has 4 million and the area is close to 20 million. Las Vegas and Phoenix should be no bigger than between 50,000 to 100,000 people. But Phoenix is the fifth largest city in the USA and Las Vegas has over half a million in the city limits alone.
So far the dams on the Colorado work but what it has done is given us two million plus sized cities and another big city where they don’t really belong. If anything happens to bust the Colorado River dams or whatever the reason, we’d have massive problems, 'cause simply Phoenix and Las Vegas shouldn’t be that large.
Oddly enough Las Vegas, Los Angeles and Phoenix, are still attracting industry dependent on yet even MORE water, while Buffalo, Cleveland, Detroit and other Great Lake cities with an over-abundance of water lose industry.
So it’s no simply a matter of supply and demand always
How do they get all that water from Lake Mead all over the Southwest?
Who is talking about the Rockies? A route through Texas, New Mexico, Arizona and through southern CA wouldn’t get close to the Rockies.
Like the existing FEDERAL highway system, the canal would be maintained by the Federal government. Besides, all the states along the way could take some of the water. It wouldn’t be just for CA.
Evaporation doesn’t seem to be as issue along the California aqueduct between the Colorado River and southern CA.
There are lots of mountain ranges in New Mexico and Arizona. My hometown, Las Cruces, is nearly a mile above sea level. And we are in one of the lower parts of the state.
It would seem much simpler just to have the people in the southwest move to the midwest. If the Phoenix area is lacking water, regulate usage or increase the price of water to reflect its scarcity. If you don’t want to deal with that you can always pack up and move to Michigan.
To elaborate: there are mountain ranges running the entire length of the continent. In the US, they are called the Rockies. In Mexico, they are called the Sierra Madre. In New Mexico and Arizona, they have a few other names. Where one ends and another begins is largely an arbitrary distinction made by some mapmaker. But the Continental Divide runs right through New Mexico, and even our flatlands are at high elevations.
I mentioned the Rockies. But no matter how you get there, you still need to go through some pretty high territory.
http://birrell.org/andrew/reliefMaps/250652560v2.mediumRes.jpg
Evaporation (and leakage) are significant problems with the California Aquaduct system and even more so with the Colorado Aquaduct. And the o.p. doesn’t seem to grasp that water only moves downhill unless pumped (at great cost) back up; check out the elevations of your course and you’ll find that you’re going up and down repeatedly. Large irrigation systems are dependent upon irrigable land being downhead of the irrigation source, or having a local source of groundwater that is relatively accessible.
In any case, attempts to control or redirect rivers have been some of the largest and often failed engineering projects ever attempted, including the Old River Control Structure (to control the divergence of the Mississippi and Atchafalaya Rivers), the Marala Headworks and Chashma Right Bank Irrigation Project in Pakistan, the Aswan High Dam, and the Great Man-Made River Project in Libya, all of which have had substantial cost overruns on their multi-billion dollar price tags and unanticipated detrimental environmental impact. The long-term viability of all of these projects is questionable at best; see John McPhee’s The Control of Nature for a discussion of the ORCS and its ultimate disposition.
Stranger
You still haven’t addressed the problem of crossing other rivers. There are several basins in the way, including the Arkansas and the Rio Grande.
Or of the slope: say you started in Saint Louis, which is about 460 feet above sea level. To end up at sea level in San Diego, 1600 miles away, your average slope is 0.00005 feet per foot. This is much too small. The minimum slope for pipe is 0.005 feet per foot, for canals it is more like 0.2 feet per foot.
Let’s say the canal comes through Las Cruces, which as mbh says is 5280 feet above sea level. The bottom of the canal has to be, oh, 300 feet above sea level. The sides of the canal can’t be straight up and down, they have to be on a slope - let’s say 3:1. That makes the sides of the canal extend out about 3 miles in either direction. That’s rather unwieldy don’t you think?
The lowest point on the continental divide trail, which any canal must cross, is 3,900 feet near Columbus, New Mexico.
The elevation of the Mississippi River is 686 feet (209 m) in Minneapolis, where it joins with Minnehaha Creek.
So at a minimum you’d have to lift your canal water 3,214 feet to get it over the divide.
Plus, water is seasonal. The Missourissippi only floods for a few weeks every spring, when the snows melt, but the big cities you’re talking about bringing the water to need it year-round. You’d have to build not only a huge canal, but also a huge reservoir.
Elevation issues are one thing… how about distance? You’re talking about a canal 1600 miles long, not counting any turns it might have to make. For comparison’s sake, the Panama Canal is 50 miles long. The Erie Canal is around 350.
Some of these problems wouldn’t exist if we build a pipeline, rather than a canal. It works for oil in Alaska, even through mountain ranges.
The elevation problem would still exist. You’d either have a pipe buried thousands of feet deep, or a lot of pumping stations to pump the water vertically. Not only expensive to build, but expensive to maintain.
The TransAlaskan pipeline is half the length and is funded by private enterprise.
The real reason?
Money.