Environmental Pool Management Riverine Systems
Upper Mississippi River, Missouri, United States
Improving ecological conditions through water management. In the early 1990s, state and federal natural resource partners on the Upper Mississippi River asked the U.S. Army Corps of Engineers (USACE)–St. Louis District to modify lock and dam operations at Lock and Dam 24 in Clarksville, Missouri; Lock and Dam 25 in Winfield, Missouri; and Melvin Price Lock and Dam in Alton, Illinois, to improve ecological conditions. To accomplish this, the St. Louis District increased the growth of aquatic vegetation during the summer while maintaining the authorized 9-foot (2.7-meter) navigation channel and staying within existing operating limits, a technique now known as environmental pool management. Over 30–40 days, the decrease in surface water elevations for about 160 kilometers exposes mudflats along riverbanks, around the perimeter of islands, and on the interior sloughs of islands, establishing optimal growing conditions. In 2015, the district began targeting 90 days of operation during the growing season, resulting in over 110 days of plant growth each year and reestablishing a perennial vegetation community of native arrowhead (Sagittaria latifolia) last seen in 1993. Monitoring efforts reveal improved sediment consolidation, fish and wildlife habitat, and critical pollinator habitat. With environmental pool management, the district has achieved ecosystem benefits while maintaining a safe and dependable navigation channel.
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