What to do with the water come flood time has been an issue for the Corps of Engineers since the 19th century. Levees kept it off the fields until the levees broke, and the levees broke massively in 1927.
After the Flood of 1927, which inundated the Lower Mississippi Valley from valley wall to valley wall, the Corps of Engineers built retention dams on the upland tributaries to the Mississippi. The engineers designed the reservoirs that formed behind the dams to withhold water from a flooded Mississippi until it could handle it.
Over time the reservoirs came to have two functions: flood control and recreation, which operated at cross purposes. In order for them to be effective for flood control, water levels in the pools needed to be kept low so there would be room when the rains came. But the anglers, boaters, camper, and others who used the pools for recreation wanted them full, but there would be no room when the rains came.
Early in my study of the Mississippi and its tributaries, I spent a morning with a potomologist with the St. Louis District with the Corps of Engineers. His job was to determine where the water went when along the Kaskaskia River. When I first called for an appointment, he told me to go away. It was flood season and the farmers, who tilled fields along the Kaskaskia, wanted the water off their fields, but the Mississippi was full, the Kaskaskia was full and so were reservoirs. There was no place to drain the excess water to.
His complaints echoed the trade-offs the Corps has to make when it releases water to the Atchafalaya from the Mississippi, which John McPhee described in “Atchafalaya.” The crawfishers want the water high, the shrimpers want is low. Navigation wants it high to avoid dredging, the cities want it high to keep saltwater out of their sources of drinking water. The farmers want is low to keep it off their fields. When the water is very high, everyone wants it gone.
Take the issue of the Black River in Arkansas and Clearwater Lake, its headwater reservoir, in Missouri.
In modern times the Black is fast-moving Ozark stream, popular with canoeists in Missouri, a tributary to the White River in Arkansas. Together they form a continuous stream along the western edge of the Western Lowlands. The Black rushes out of the Ozark highlands into the lowlands, lays down its alluvial fan, and slows to a meander; so slow that the river and its backwaters can support a cypress swamp at Arkansas’s Dave Donaldson-Black River Wildlife Management Area.
The Arkansas Game and Fish Commission purchased the Dave Donaldson-Black River Management Area in the 1950s and 1960s in order to salvage 25,000 acres of bottomland forest and Black River wetlands from ever-expanding soybean and rice fields.
The refuge provides overwintering habitat for waterfowl and spring nesting areas for neotropical birds. Every winter resource managers flood seven thousand acres of greentree forest after the trees, primarily acorn-bearing oaks, have gone dormant to attract waterfowl, particularly mallards and wood ducks. They farm another two hundred acres with specialized crops to attract the birds. Foresters thin trees on portions yearly to stimulate new growth and diversify habitat. In 1998 managers developed the Brookings Moist Soil Unit to produce food for overwintering ducks, shorebirds, and wild turkeys. Hunters, armed with crossbows or muzzle-loading rifles, stalk the refuge for deer, squirrel, beaver, raccoon, muskrat, and mink.
Since 1958 the Corps of Engineers has regulated the amount of water that flows to the management area. In 1958 the Little Rock District of the Corps of Engineers completed the Clearwater Lake Dam Project, a flood control project authorized in 1938. Built on the Black River at river mile 257.4 in the Missouri Ozarks, far upstream from the Black River WMA, Corps’ engineers designed the reservoir behind the dam to control flooding downstream, particularly of the Arkansas cotton and soybean fields. The pay-off for Missourians was Clearwater Lake, a mecca for campers, canoeists, boaters, anglers, and swimmers.
The Corps releases more water from the reservoir during the winter duck season when it maintains a river stage of 11.5 feet at Poplar Bluff, Missouri. The engineers release less water during the growing season, March 1 to November 30, when it maintains the river at Poplar Bluff at 10.5 feet, keeping water off the fields downstream of the dam. Over the years Arkansas farmers asked for and got numerous deviations from the water control plan at Clearwater Lake.
Because there were so many repeated requests for changes in the amount of water retained in Clearwater Lake during the growing season, the Little Rock district of the Corps began working with Clearwater Lake/Black River Committee–made up of folks interested in changing the management of the reservoir–and government agencies to develop a new plan that matched the needs of basin users. In 1998 the committee endorsed an alternative water control plan that would keep water off the fields during the growing season by releasing water from the lake very slowly and maintaining the Black River at four feet at Poplar Bluff.
In 1999 the Corps completed its draft environmental assessment of the plan and sent it to other agencies for comment, including the Arkansas Fish and Game Commission. While the plan would keep water off the fields, the Commission noted that the four-foot stage at Poplar Bluff would soak the bottomland hardwoods in the Dave Donaldson Wildlife Management Area for long periods, possibly damaging their roots. The plan was shelved after study proved that the four-foot stage could damage the trees.[i]
Find an interesting discussion of the issue of how the Corps managements the reservoirs on the White River here.
[i] U.S. Army Corps of Engineers, Little Rock District, “Black River Control Plan,” http://www.swl.usace.army.mil/planning/blackriver.html; Telephone conversation with Chris Hicklin, Black River Water Control Plain, Little Rock District, July 2, 2004.