Allegheny River Lock and Dam No. 4 facts for kids
Quick facts for kids |
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Allegheny River Lock and Dam No. 4
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Location | 1 River Avenue, Harrison Township, Allegheny County, Pennsylvania |
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Built | 1927 |
Architectural style | Moderne |
MPS | Allegheny River Navigation System MPS |
NRHP reference No. | 00000398 |
Added to NRHP | April 21, 2000 |
The Allegheny River Lock and Dam No. 4 is an important structure on the Allegheny River in Harrison Township, Allegheny County, Pennsylvania. It includes a special gate called a lock and a dam. This system was built between 1920 and 1927. It officially opened in 1927.
The U.S. Army Corps of Engineers built this lock and dam. Their goal was to make it easier for boats to travel along the Allegheny River. This lock and dam is part of a larger system of similar structures.
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Where is it Located?
This lock and dam is about 24.2 miles upstream from where the Allegheny River meets other rivers in Downtown Pittsburgh. That meeting point is near Point State Park. It is also about 6 miles downstream from where the Kiskiminetas River flows into the Allegheny.
How the Lock and Dam Works
The Allegheny River is divided into different sections, like steps, by locks and dams. These sections are called "pools." Lock No. 4 connects two of these pools.
- Upstream, Pool No. 4 has a water level of about 745.4 feet above sea level. This pool stretches about 6.2 miles upstream to Lock and Dam No. 5.
- Downstream, Pool No. 3 has a water level of about 734.5 feet above sea level. This pool extends about 9.7 miles downstream to Lock and Dam No. 3.
Lock No. 4 helps boats move between these two pools. It can lift or lower boats by about 10.9 feet. This allows them to travel safely along the river.
The dam itself is a "fixed-crest dam." This means its top is at a set height. It helps keep the water in the pool above it at least 9 feet deep. This depth is important for boats to navigate. The dam also helps provide water for nearby towns. However, it does not control floods.
What Travels Through the Lock?
Many different goods are shipped through Lock No. 4. In 1998, about 1.8 million tons of materials passed through. These included important items like coal, oil, sand, and gravel. Other goods were steel, chemicals, and even food items like flour.
A Historic Landmark
The Allegheny River Lock and Dam No. 4 is recognized as an important historical site. It was added to the National Register of Historic Places on April 21, 2000.