doi:10.2489/jswc.71.4.91A FEATURE St. Johns Levee and Drainage District attempt to mitigate internal flooding Lois Wright Morton and Kenneth R. Olson hen the Mississippi River reaches Figure 1 87.9 m (290 ft) above sea level A riverboat on the Mississippi River can be seen passing the outlet of Main Ditch, W near New Madrid, Missouri, which drains through the 454 m frontline levee gap at New Madrid, Missouri, to the bottomlands adjacent to the river and Mississippi River. farmland, roads, ditches and wetlands begin to flood. Concurrently, at the lower end of the New Madrid Floodway the rising Mississippi backs up into Main Ditch (figure 1), the 454 m (1,500 ft) gap in the frontline levee designed to drain the Floodway and St. Johns Levee and Drainage District to the river (figure 2). When this occurs, the Main Ditch gates Copyright © 2016 Soil and Water Conservation Society. All rights reserved. on the setback levee (figure 3) are closed Journal of Soil and Water Conservation to protect the St. Johns Bayou basin from Mississippi River backflow. However, with the Main Ditch gates closed, precipitation within the basin has no outlet as it drains to the Main Ditch channel. This causes tributary streams to back up and flood a substantive portion of agricultural lands and the town of East Prairie, Missouri. For example, the 19 cm (7.5 in) of rain during the first three days of May of 2011 backed up local floodwater in the St. Johns Bayou Whenever heavy snowmelt and pro- GEOLOGICAL HISTORY 71(4):91A-97A basin all the way to East Prairie. longed rains occur in the upper Mississippi Historically the path of the Mississippi The construction of the Commerce to and Ohio river valleys, the people of this River just south of Cape Girardeau Birds Point to New Madrid levees (figure region watch the river gage numbers turned southwest into the current state 2) artificially separated lands within St. with concern for high water river pres- of Missouri. It then traveled more than www.swcs.org Johns Bayou basin and the New Madrid sure threats to their levee systems and 40 km (25 mi) to the west (Olson and Floodway from their natural drainage internal flooding of low-lying areas from Morton 2014a) before turning south paths to the Mississippi River. While drainageways. Table 1 illustrates how dif- toward Morley, Missouri, where it joined much of the farmland behind these levee ferent Mississippi River high water events with the ancient Ohio River waters systems are protected when the waters of affected the acreages that were flooded in draining through the Cache River valley the Ohio and Mississippi rivers exceed St. Johns Bayou basin and New Madrid (ancient Ohio River valley) (Olson and flood stage, thousands of hectares (thou- Floodway in 1997, 2008, and 2011. The Morton 2014b). The historic confluence sands of acres) of bottomlands are flooded United States Army Corps of Engineers near Morley, Missouri, was 47 km (30 mi) through the gap in the lower New Madrid (USACE) has responsibilities for many north of the current confluence of the Floodway frontline levee. In addition, the aspects of the Mississippi River including Mississippi and Ohio rivers located south closure of the setback levee gates at the flood control, river navigation, and flood- of Cairo, Illinois (figure 2). gap results in many more thousands of plain ecosystems. In recent years USACE The Mississippi River realigned at the hectares (thousands of acres) in St. Johns flood mitigation planning in the Bootheel end of the Great Ice Age. After the last gla- Bayou basin being internally flooded. of Missouri has attempted to reduce the cier advance, the melting ice flooded and number of days communities are isolated altered the course of many channels and by floodwaters, limit crop and non-crop streams including the Mississippi and Ohio Lois Wright Morton is professor of sociology, in the College of Agriculture and Life Sciences, losses, and reduce damage to critical infra- rivers (Olson and Morton, 2013a, 2013b). Iowa State University, Ames, Iowa. Kenneth structure by adopting flexible strategies The 9.3 km (6 mi) stretch of the Mississippi R. Olson is Professor Emeritus of soil science that reconnect the hydrology of the flood- river just north of Commerce, Missouri, in the College of Agricultural, Consumer, and Environmental Sciences, University of Illinois, plain to the river. is historically unique (Olson and Morton Urbana, Illinois. 2014a). This stretch of the Mississippi River valley is very narrow and lacks the wide JOURNAL OF SOIL AND WATER CONSERVATION JULY/AUGUST 2016—VOL. 71, NO. 4 91A alluvial bottomland typically found along Figure 2 the Mississippi River. Once the ancient Map of St. Johns Bayou basin and New Madrid Floodway, Missouri. The systems of Mississippi Valley was no longer connected levees that protect agricultural lands from Mississippi River flooding have altered the to the Mississippi River, the alluvial bot- natural internal drainage of both these basins. Map by Mic Greenberg. tomlands south of Commerce and Benton, Commerce Commerce Farmer levee LATITUDE 37 0' Missouri, became a swamp called Tywappity Horseshoe N Breach Lake Bottom (figure 2). 57 61 The Mississippi River, during this 77 Benton Miller Mound prehistoric period, migrated rapidly by City City 55 eroding the outside of river bends and Morley Legend St. Ohio depositing sediment on the inside of the John’s River North Birds-Point New Ditch bend. Abundant oxbow lakes mark old Madrid Floodway Cut Ditch Cairo positions of the channel that have been Kentucky Illinois disconnected from the river. This historic 60 61 Parkland and meandering is apparent in the floodway wetlands Scott Commerce to Missouri area County and St. Johns Bayou basins where topo- drains directly into Birds Point Birds 77 levee Mississippi Point 1 graphical maps reveal swirls and curves St. John’s Charleston Wilson City Bayou Drainage Copyright © 2016 Soil and Water Conservation Society. All rights reserved. District 60 from previous oxbows across the landscape. Journal of Soil and Water Conservation 60 Interstate 57 Wyatt 57 highways Sikeston Mississippi Levees Mississippi County THE BOOTHEEL OF MISSOURI 77 County 105 Gully Breach 60 fields St. John’s The Bootheel is the wettest region in the County boundaries Gully Bayou fields Drainage Anniston state of Missouri with annual rainfall averag- Roads District Floodway ing 1.4 m (55 in). As a result of its proximity East 75 Railroads 55 Prairie 61 to the Mississippi River, the region expe- Water, lakes, 80 rivers, ditches 60 Pinhook riences frequent headwater and backwater Blast site 80 Wolf 1 Birds Point Site Island flooding (table 1). Headwater flooding is of 2 New Madrid Ten Mile sand- Big Oak Tree Pond caused by drainage of rainfall from sur- 3 bagging Conservation Big F Ferry Madrid Area 102 Oak rounding uplands. Backwater flooding County New Madrid Tree County Seat 71(4):91A-97A occurs during seasonally high water events County State Park City or village when snowmelt and rain from upstream 3 Mississippi River Pumping New Gate 102 station Madrid tributaries raise Mississippi River levels and Dorena create backup into riverine bottomlands. 4 km Gap F 94 55 2.5 mi 2 Seven Island Hickman When Spanish explorers in the 1700s passed Conservation www.swcs.org through the area, these southeast Missouri Area lowlands supported 1 million ha (2.5 million LONGITUDE 89 7' 30'' ac) of bottomland hardwood and swamp forests with an occasional slightly higher dry zone of bottomland, which by the late Table 1 1800s could be planted to cultivated crops Floodwater heights in 1997, 2008, and 2011 and corresponding area flooded in New The soils are rich and fertile, but settlers Madrid Floodway and the St. Johns Bayou basin. had difficulty harvesting hardwood timber Flooding in New Flooding in St. from wetland soils and swamps. Farming Mississippi River Madrid Floodway St. Johns Bayou Johns Bayou the cleared timber soils was difficult, and Date height (m) basin (ha) basin height (m) basin (ha) the land remained relatively cheap until March 16,1997 90.4 26,780 90.0 10,152 farmers developed strategies for draining it. April 15, 2008 90.0 23,342 89.8 14,106 The draining of the Tywappity bottomlands May 1, 2011 90.7 28,000 90.1 16,000 south of Benton and Commerce, Missouri (figure 2), was accomplished by clearing and burning of trees and stumps, construct- COMMERCE, MISSOURI, FARMER about 3 km (2 mi) south of Commerce ing drainage ditches to aerate the soil, and LEVEE AND DRAINAGE (figure 2). This breach occurred when a then cultivation. By 1975 only 40,000 ha DISTRICT BREACH sand boil undermined the earthen levee (100,000 ac) of original forest remained in During the Great Flood of 2011, the shortly after the New Madrid Floodway both the St. Johns Bayou and the adjacent Commerce farmer levee located between was opened on May 2 to relieve the pres- Little River Levee and Drainage District the USACE Commerce to Birds Point sure on the floodwalls and levees near the located to the north, west, and south. levee and the Mississippi River breached confluence of the Ohio and Mississippi 92A JULY/AUGUST 2016—VOL. 71, NO. 4 JOURNAL OF SOIL AND WATER CONSERVATION Figure 3 flood stage and opening to permit drain- The New Madrid Floodway setback levee gate is used to drain the St. Johns Bayou age through the Main Ditch when the basin to the Main Ditch and under flood conditions prevents Mississippi River backup Mississippi River was low (figure 1). The water from flowing into the basin. Main Ditch to the river currently drains approximately 120,000 ha (300,000 ac), including 40,000 ha (100,000 ac) of the floodway and 80,000 ha (200,000 ac) of St.