Lock and Dam No. 21st
| Lock and Dam No. 21st | |
|---|---|
|
|
| Basic data | |
| Places: |
Quincy , Illinois Marion County , Missouri |
| Geographical coordinates: | 39 ° 54 '22 " N , 91 ° 25' 56" W |
| Construction time: | 1933-38 |
| Weir | |
| Type: |
Segment weir roller weir |
| Maximum storage height: | 2.7 m |
| Dam length (moving part): | 385.6 m |
| lock | |
| usable length: | 182.9 m |
| usable width: | 33.5 m |
Lock and Dam No. 21 ( Lock and Barrage No. 21 ) is one of 29 barrages that allow navigation on the Upper Mississippi . Erected between 1933 and 1938 by the United States Army Corps of Engineers , the combined structure is located in Quincy , Adams County , Illinois . On the opposite right bank of the river is Marion County , Missouri . In 2004 the Lock and Dam No. 21 Historic District included in the NRHP .
Barrage
The barrage includes a 426.7 m long stone dam on the Missouri side and a 385.6 m long adjustable part, which consists of a ten-part segment weir and three dam rollers .
The water level is 9 feet (2.70 m). The purpose of the weir is not flood protection, but 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.
Individual evidence
- ↑ Extract from the National Register of Historic Places - No. 04000181. Retrieved July 26, 2012