Lock and Dam No. 12
| Lock and Dam No. 12 | |
|---|---|
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| Weir | |
| Type: |
Segment weir roller weir |
| Maximum storage height: | 2.70 m |
| Dam length (moving part): | 258.8 m |
| lock | |
| usable length: | 182.9 m |
| usable width: | 33.5 m |
| Lock and Dam No. 12 Historic District | |||
|---|---|---|---|
| National Register of Historic Places | |||
| Historic District | |||
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| location |
Bellevue , Iowa Jo Daviess Ct. , Illinois |
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| Coordinates | 42 ° 15 ′ 41 " N , 90 ° 25 ′ 13" W | ||
| surface | 41.2 ha | ||
| Built | 1934-1938 | ||
| architect | Edwin E. Abbott | ||
| NRHP number | 04000172 | ||
| The NRHP added | 2004 | ||
Lock and Dam No. 12 ( Lock and Barrier No. 12 ) is one of 29 barrages that allow navigation on the Upper Mississippi . Built between 1934 and 1938 by the United States Army Corps of Engineers , the combined structure is located between Bellevue , Iowa and Jo Daviess County , Illinois . In 2004 the Lock and Dam No. 12 Historic District included in the NRHP .
Barrage
The barrage includes a stone dam on the Illinois side and a 258.8 m long adjustable part, which consists of a seven-part segment weir and three barrage rollers .
The water level is nine feet (2.70 m). The purpose of the weir is not primarily to protect against flooding, but to damming the Mississippi for shipping.
lock
The lock is 182.9 m long and 33.5 m wide. Next to it is a second, but not completed, smaller lock chamber.