Lock and Dam No. 9

File:Mississippi River Lock and Dam number 9.jpg Mississippi River Lock and Dam number 9.
Location	Taylor Township, Allamakee County, Iowa / Seneca, Crawford County, Wisconsin, near Lynxville, Wisconsin, USA
Coordinates
Construction began	1936
Opening date	July 1937
Operator(s)	United States Army Corps of Engineers
Dam and spillways
Impounds	Upper Mississippi River
Reservoir
Creates	Pool 9
Total capacity	470,000 acre·ft (0.58 km3)
Catchment area	66,610 sq mi (172,500 km2)

Lock and Dam No. 9 is a lock and dam located near Lynxville, Wisconsin and Harpers Ferry, Iowa on the Upper Mississippi River around river mile 647.9. The lower portion of Pool 9 was formally named Lake Winneshiek. The normal pool elevation behind the dam is 620 feet (189.0 m). It was constructed and placed in operation in July 1937. The site underwent a major rehabilitation from 1989 and 2006. The dam consists of concrete structure 811 feet (247.2 m) long with five roller gates and eight tainter gates. Earth embankment 9,800 feet (2,987.0 m) long with a grouted overflow spillway 1,350 feet (411.5 m) long. The lock is 110 feet (33.5 m) wide by 600 feet (182.9 m) long. Lock and Dam No. 9 is located 12 miles upstream from Prairie du Chien, Wisconsin.

External links

• U.S. Army Corps of Engineers, St. Paul District: Lock and Dam 9
• U.S. Army Corps of Engineers, St. Paul District: Lock and Dam 9 brochure
• Lock and Dam No. 9 Fishing Forum
• USGS Reach 1, Pool 9
• Survey number HAER WI-50 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville vicinity, Crawford County, WI
• Friends of Pool 9 - Nonprofit organization dedicated to keeping the pool clean, managing annual volunteer cleanups, particularly of backwaters