Illinois American Water, supplier of drinking water to more than 250,000 metro-east residents, is making emergency preparations to deal with the dwindling level of the Mississippi River.

Without the move, the water supply could soon dry up for communities in Madison and St. Clair counties.

"Right now our team is making an investment of about $400,000 at the East St. Louis water treatment plant which will allow access to water at a much deeper level of the Mississippi River than our usual intakes can reach," Illinois American Water spokeswoman Karen Cotton said Thursday. "A protective wall is also being built to protect the temporary intake which we expect will remain in place until the spring."

Citing security concerns, Cotton would not say how deep the current intakes reach or how much deeper the temporary lines will go. But she said that company leaders believe the additional reach will guarantee water keeps flowing to metro-east taps even if the Mississippi drops to record setting low water levels.

According to the U.S. Coast Guard, the Mississippi River water level at St. Louis is about 2 feet below normal. But it is expected to fall to about 6 feet below normal in the next two weeks as the annual winter restriction of water flow from the Missouri River takes effect. The lowest recorded level at St. Louis is 6.2 feet below normal recorded in 1940.

Because the Missouri usually gets low in the winter, the U.S. Army Corps of Engineers restricts its flow into the Mississippi River from November until the spring when snow melt upstream replenishes the water supply.

It's been a tough year for Illinois American, Cotton said. Even before the level of the Mississippi River became an issue, the company spent a busy summer repairing water mains damaged because of dry soil created by the drought. The company also faced extremely high demand on its supply because lawn destroying dry weather and high temperatures.

According to the city of St. Louis' annual water report, water on the west side of the Mississippi River comes from both the Mississippi and Missouri rivers. So St. Louis should have access to water regardless of whether the Missouri river is opened up.

Farther downstream, the low level of the Mississippi River has threatened the water supply in parts of Louisiana, according to a story in the New Orleans Times-Picayune.

Salt water from the Gulf of Mexico has been allowed to creep up the river because of the decreased fresh water flow downstream, according to the Times-Picayune. Leaders there believe the salt water will reach river water intakes within three weeks if nothing is done. The Corps of Engineers is considering construction of an underwater sill to block the salt water which sinks to the bottom of the river because it is heavier than fresh water.

Things don't seem likely to get better on the river system anytime soon.

According to an Associated Press report Thursday, the Midwest is again slipping into drought conditions after some temporary relief at the end of the summer. About 96 percent of Nebraska and 78 percent of Kansas are in extreme or exceptional drought condition, the two worst categories. Nearly 63 percent of land in the lower 48 states is in drought condition.

U.S. Department of Agriculture spokesman Eric Luebehusen said light showers are all that can be expected in the Mississippi Valley over the next week.

"Otherwise, dry, warm conditions are expected across the remainder of the contiguous U.S., affording most drought areas little -- if any -- relief over the next five to seven days," Luebehusen wrote in a Wednesday climate report.

The last time Illinois American had to temporarily extend its reach into the Mississippi River was in 1989-90 when water levels in St. Louis reached near 6 feet below normal.

Contact reporter Scott Wuerz at swuerz@bnd.com or call 239-2626.