FLOOD09407 - Laserfiche WebLink

Home Browse Search

flood events in this nation's history, flooded over 6.6 million acres in the 419 counties in the study area.' The damages experienced reflected the land-use and settlement patterns within and adjacent to the floodplain. The floodplains along the main stem Mississippi and Missouri rivers and the major tributaries that were inundated generally are used for agriculture, and most areas are sparsely populated. Throughout most of the area, river towns are protected by urban levees, or they are located primarily on a bluff. Floodwaters thus inundated neighborhoods rather than entire communities. Residences, businesses, and industries did receive extensive damages in bottomland areas and along tributaries near Kansas City and SI. Louis. Development in these urban areas, however, is largely in the uplands or protected by urban levees that provided flood protection. As a point of comparison, significantly fewer people were impacted by the Midwest Flood of 1993 than were impacted by the 1927 flood on the lower Mississippi River. Floodplain land-use patterns. Above Rock Island, Illinois, the Mississippi River valley is relatively narrow and bottomlands are filted to a large extent by navigation pools -- the slack water pools that form behind navigation dams. Most of the remaining floodplain in this area is contained in wildlife refuges with limited agriculture. Along this reach of the river are scattered towns settled during the steamboat era that have developed as market centers and service areas for agricultura1 hinterlands. Industries were established in many of these towns to take advantage of river navigation and the railroads that later foltowed the river valleys. Such towns generally have been protected by urban levees or are largely out of the floodplain. Below Rock Island the valley widens out to as much as six miles. The extensive bottomlands in these areas are protected by agricultura1levees and used for crops. The leveed areas include farmsteads and a few smail farm communities entirely within the floodplain. Missouri River bottomlands, used predominantly for agriculture, are protected to varying degrees by levees. On the fringes of the bottomIands are small farm communities. In the adjoining uplands a number of larger communities are located on the bluffs above the valtey. 6 THE FLOOD OF 1993 Developed floodplains with larger urban areas such as Omaha/Council Bluffs, Kansas City, and SI. Louis are largely protected by levees. Near Kansas City and SI. Louis, several residential, industrial, and commercial areas are built on floodplains behind levees that overtopped or failed in 1993. Other residential, industrial, or commercial areas were flooded along the larger tributary streams in these urban areas. Rural subdivisions are scattered along the river, many of which began as hunting and fishing camps and evolved into year -around communities. These subdivisions provide inexpensive housing in part because of cheap land, lack of services such as sewer and water, limited land-use controls, and few building requirements. On the major tributaries, the patterns of development are much the same as along the Mississippi and Missouri main stems, although the bottomIands are narrower with fewer farmsteads. The smail towns along these tributaries often have floodprone neighborhoods, but most of the population lives in the adjoining uplands. Table 1.1 includes infonnation on land use and land cover categories for the floodplain and the flood extent for the study area. The estimates of land use and land cover were developed using satellite imagery. '" , 't!; I ..~. ~ i- t -l ,~. , '~ Population trends. In general rural counties declared disaster areas in the nine states affected by the 1993 flood are losing population. No data are availa1l'e on gain or loss of floodplain populations during this period. The only comparable data from the 1980 Census and the 1990 Census are aggregated by county or community. Population increases that have occurred are generally in the suburban counties of major urban areas such as Minneapolis/SI. Paul, Des Moines, Kansas City, and St. Louis. Loss of population in rura1 areas is the result of farm consolidation, lack of employment opportunities, and improvements in transportation. Fewer farmers mean a lower demand for local goods and services, which has a ripple effect on the local economy. Those who remain on the land drive to larger communities to shop and for many of the services previously provided by farm towns. Such trends, not unlike those occurring throughout the nation, are limiting development pressure within the floodplain. Figure I. 2 shows the population gain or loss by county