Very interesting article about what America has done to the river and Louisiana

[RB TexLa]

I'll keep my comments to myself.



Sediment that used to flow down the Mississippi River is now locked up behind dams and levees. The sediment that does make it down river is channeled into the depths of the Gulf of Mexico rather than spreading through the wetlands that surround the river’s end. With no river sediment to sustain them, coastal wetlands are sinking into the sea. And the thousands of miles of canals dredged for oil and gas drilling have turned coastal areas into a patchwork quilt of wetlands that are isolated from the freshwater they need to survive or are enveloped by encroaching saltwater. Fish and wildlife that depend on these wetlands – for nurseries, nesting areas, food sources, or a rest stop during migration – are losing them at a frightening pace


Soft sediments like those found in the Mississippi delta naturally sink. For thousands of years, sinking wetlands were replenished by the same river sediment that built them – a natural process that kept some of the land above water. Today, however, locks and dams keep some of that sediment from moving down river. Levees built along the sides of the river to prevent flooding also prevent sediment from entering the river after a flood and increase the speed of floodwaters.



Up-river construction projects cut the amount of sediment carried down the Mississippi River by as much as 60 percent, says David Muth, Louisiana state director for the National Wildlife Federation, who spent 30 years working for the National Park Service in Louisiana. The sediment that does manage the journey down to the delta does not replenish the wetlands – it’s lost at sea. The Mississippi River Commission and the Corps built jetties at the mouth of the river to keep a deep channel open for ocean- going ships. However, the jetties confine the river sediment. The Corps of Engineers also dredges the river bottom to ensure the river is deep enough for these ocean-going vessels. “About 90 percent of what the Corps spends on dredging in United States is spent on the lower Mississippi River,” says Muth. The deep river bottom at the mouth of the Mississippi sends sediment out into the Gulf of Mexico, where it falls hundreds of feet down into the water and drifts away.


http://www.iwla.org/index.php?ht=display/ContentDetails/i/15269

[Mimosa]

1. Best informational article about the Mississippi and wetlands in years.

Thank you!

[postulater]

2. Thanks.