Lock and Dam No. 11

Lock and Dam No. 11
Hawkinson Aerial Photography, LLC · CC BY 2.5 · source
Name	Lock and Dam No. 11
Location	Clayton County, Iowa / Grant County, Wisconsin
River	Mississippi River
Operator	U.S. Army Corps of Engineers
Opened	1937–1939
Type	Fixed weir and gated dam with lock

Lock and Dam No. 11 Lock and Dam No. 11 is a major navigation and water-control facility on the Mississippi River between Dubuque, Iowa and Galeton, Wisconsin near Princeton, Iowa and Potosi, Wisconsin. Built by the United States Army Corps of Engineers during the New Deal era, it forms Pool 11 and supports inland barge traffic, flood risk management, and regional recreation. The site is proximate to Upper Mississippi River National Wildlife and Fish Refuge, the Mississippi Flyway, and transportation corridors such as U.S. Route 52 and Iowa Highway 3.

Overview and Location

Located on the Upper Mississippi River mainstem, the facility sits downstream of Lock and Dam No. 10 and upstream of Lock and Dam No. 12, forming Pool 11 that extends near Dubuque, Iowa, Keokuk, Iowa, and Prairie du Chien, Wisconsin. The project spans state lines between Iowa and Wisconsin, adjacent to county seats like Clayton County, Iowa and Grant County, Wisconsin. It lies within the geographic context of the Driftless Area, the Midwestern United States, and the broader Ohio River Basin watershed. Nearby towns and features include Guttenberg, Iowa, McGregor, Iowa, Bellevue, Iowa, and the Upper Mississippi River Valley National Heritage Area.

History and Construction

Authorized under federal river improvement programs of the early 20th century, construction commenced under the auspices of the U.S. Army Corps of Engineers and New Deal agencies active during the Great Depression. Work phases overlapped with projects overseen by the Public Works Administration and employment policies of the Works Progress Administration. Construction techniques reflected contemporaneous practice used at contemporaneous projects like Lock and Dam No. 10 and Lock and Dam No. 5, drawing on engineering traditions from firms and institutions such as American Society of Civil Engineers members and alumni of Cornell University and University of Minnesota engineering programs. The facility was completed in the late 1930s, contemporaneous with federal infrastructure ranging from Boulder Dam projects to Tennessee Valley Authority works, and has since undergone periodic rehabilitation funded by congressional appropriations and managed by the U.S. Congress committees overseeing transportation and waterways.

Design and Specifications

The project comprises a concrete lock chamber paired with a movable gated dam and fixed weir components, following design paradigms developed by U.S. Army Corps of Engineers districts and influenced by innovations tested at Harbor Works and river projects along the Ohio River and Illinois River. The lock accommodates standard Mississippi River barge tows comparable to locks at Lock and Dam No. 15 and Lock and Dam No. 19; its dimensions and lift are consistent with Upper Mississippi navigation standards promulgated by federal engineering guidance from the U.S. Department of the Interior. Structural elements reference materials and methods associated with American Institute of Steel Construction specifications and concrete practice taught at Massachusetts Institute of Technology. Auxiliary systems include electrical, mechanical, and control installations comparable to those administered at Lock and Dam No. 14 and the Keokuk hydroelectric complex.

Operations and Navigation

Operated continuously by the U.S. Army Corps of Engineers, the lock supports commercial freight movements that connect the Port of New Orleans inland waterways network to Midwestern markets such as Chicago, Illinois, St. Louis, Missouri, and Minneapolis, Minnesota. Traffic includes agricultural commodities transported by companies linked to the Chicago Board of Trade and industrial shipments destined for facilities in Milwaukee, Wisconsin and the Twin Cities. Lockage procedures follow operating rules coordinated with regional navigation charts produced by the National Oceanic and Atmospheric Administration and river forecasts from the National Weather Service. Seasonal hydrology influenced by snowmelt in the Upper Midwest and precipitation patterns tied to the El Niño–Southern Oscillation affects scheduling, commercial tow sizes, and emergency management coordinated with entities such as the Federal Emergency Management Agency.

Environmental and Ecological Impact

The impoundment that forms Pool 11 interacts with habitats of the Upper Mississippi River National Wildlife and Fish Refuge, affecting species including migratory waterfowl using the Mississippi Flyway, navigational fish such as paddlefish, and sportfish valued by anglers from Iowa Department of Natural Resources and Wisconsin Department of Natural Resources jurisdictions. Ecological concerns mirror those at other river projects like Lock and Dam No. 2 and involve sediment transport, wetlands loss, and invasive species such as Dreissena polymorpha and Phragmites australis. Mitigation and adaptive management involve collaborations among federal agencies including the U.S. Fish and Wildlife Service, academic partners such as University of Wisconsin–Madison researchers, and conservation NGOs like The Nature Conservancy.

Recreation and Public Access

The site provides boat access, fishing areas, and observation points frequented by visitors from regional urban centers such as Cedar Rapids, Iowa and Quad Cities. Facilities and interpretive amenities are maintained in coordination with local tourism bureaus and park systems including State Historical Society of Iowa initiatives and county conservation boards. Nearby recreational corridors connect to trails and attractions like the Great River Road, Effigy Mounds National Monument, and regional birding sites attracting visitors during peak migration seasons documented by organizations such as Audubon Society chapters.

Category:Locks on the Mississippi River Category:Dams in Iowa Category:Dams in Wisconsin