SURVIVE THE STORM: Beware of low-water crossings

Published: Mar. 28, 2019 at 4:44 PM CDT
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Tornadoes, high winds, huge hail—those are the things that usually come to mind first when we talk about severe or dangerous weather. Each deserves the respect and attention we give them, but none of them are historically as deadly in the Ozarks as flooding.

In the last 25 years, 80 people have died in flood waters across the Ozarks—and most of them have died in vehicles swept off low-water crossings.

Some people underestimate the depth and the power of the water. They try to drive across, only to be carried downstream. For others, they are caught by surprise—hitting the water at night after topping a hill or rounding a corner.

Water can rise incredibly fast during heavy rain and knowing which of the thousands of low-water crossings in the Ozarks are flooded usually comes down to someone seeing and reporting them. Meteorologists at the National Weather Service hope to change that with a new program.

Using high-resolution mapping data from the United States Geological Survey—or USGS—runoff from rainfall in any given area can be traced. For instance, rain falling at the KY3 studios goes into Fassnight Creek, then Wilsons Creek, then the James River, into Table Rock lake, eventually down the White River, into the Mississippi River and finally into the Gulf of Mexico. Rain falling north of Kearny Street in Springfield goes north into the Sac River, Stockton Lake, Truman Lake, Lake of the Ozarks, The Osage River, Missouri River, Mississippi River, and then the Gulf. By knowing how the water will flow, the drainage area of any given low-water crossing can be mapped. Put in rainfall data from doppler radar and satellite, and it may be possible to predict what crossings will flood before they flood.

This will allow the National Weather Service to issue flood warnings that are more specific, and notify local, county, or state officials about a crossing that is expected to flood so they can put up signs or barricades.

The huge challenge, to start, is the sheer number of low-water crossings just in southern and central Missouri: over three thousand. Each of them must be mapped and catalogued by county officials, then assimilated into the National Weather Services’ computer program. There are 205 crossings on Missouri State routes, and those are already in the system. Otherwise, it is up to officials in each county to map their crossings. Newton County is complete, and the National Weather Service hopes others will soon follow.