VOA常速英语2008年-Water Diverted from Swollen Mississippi River t

The Mississippi river, which drains more than 40 percent of North America's river flow into the Gulf 1 of Mexico, is at its highest point in years, leading to concern that levees protecting the city of New Orleans could be compromised. A few weeks ago, the same conditions farther upstream caused widespread flooding in the Midwest. But, as VOA's Greg Flakus reports from New Orleans, officials of the U.S. Army Corps 2 of Engineers have taken steps to protect the city by diverting water around it.

The fortunes of New Orleans have always been tied to the river, but the river can also pose a threat.

Officials in and around New Orleans are keeping a close eye on river levels this spring as water from snow melt and heavy rains up north flow down through the Missouri, the Ohio and other rivers that connect with the Mississippi.

In order to reduce the river level around New Orleans, officials are directing some of the freshwater of the Mississippi through the Bonnet 3 Carre spillway northwest of the city into Lake Ponchartrain, a brackish-water lake that is connected with the Gulf of Mexico.

Lee Guillory, the Natural Disaster Manager for the Army Corps of Engineers in New Orleans, says this does disrupt the natural ecology of the lake, but only for a while.

"When we do a diversion through Lake Ponchartrain it does cause some temporary changes to the lake and to the fisheries in that area, but it is only a temporary measure. It also mimics 4 the natural flows that used to occur many years ago when the levees were not here. It pushes some of the salt water fisheries further out and a few more fresh water fisheries appear in Lake Ponchartrain, but it is only a temporary measure and it will return back to normal in a few months after the structure is closed and it will not cause any long term adverse 5 effects to the environment," explains Guillory.

Even with the diversion of water, the river flow is much faster than normal, which Guillory says can be a problem for boat and barge 6 operators.

"It does cause quite a few problems for the navigation industry when the river is this high because the current gets swifter, it gets wider and faster, and to maintain steerage, they have keep their speed up going downstream," he said. "Likewise, when they are going upstream, it takes additional horsepower and more tug 7 to push the same amount of load that they would push in a normal river, a slack river."

The Corps of Engineers also maintains the levees that protect the city from being flooded by a surge from a hurricane, such as happened nearly three years ago when Hurricane Katrina passed through.

But Lee Guillory says efforts to strengthen the levees to withstand a once-in-a-century storm are on track.

"The city is in fairly good shape," he said. "We have restored most of it to the authorized 8 height and depth, but we are also going beyond that and have made commitments to increase it to the 100-year-level of protection by the year 2011."

Water is the life blood of this area, but it takes constant vigilance and effort to keep it in its place.