3 July 2024
What occurs when a dam is got rid of from a river? We’re about to determine at the Monongahela River at Elizabeth, PA. On 10 July, climate and river allowing, the US Military Corp of Engineers (USACE) will start disposing of Locks and Dam 3, often referred to as the Elizabeth Locks and Dam. Inbuilt 1907 is likely one of the oldest such buildings within the U.S.
This animation from USACE displays how it is going to be achieved.
Preferably the removing of a dam would repair the river to a extra herbal state however Pittsburgh’s 3 rivers are a sequence of swimming pools — like lakes — created for navigation by means of a lot of locks and dams.
The dam at Elizabeth is 12.6 miles upstream from Locks and Dam 2 at Braddock and 23.8 miles downstream from Locks and Dam 4 at Charleroi. When the primary hole is made within the Elizabeth dam it is going to take 3 days for the water stage to stabilize right into a pool 36.4 miles lengthy stretching from Braddock to Charleroi. No, the Monongahela River is not going to revert to a herbal state however there shall be different results.
As demolition continues on the remainder of the dam, its removing will unencumber sediments similar to silt, clay, sand and gravel that experience constructed up in the back of the dam for greater than 100 years. Taking into account Pittsburgh’s business previous, the sediments might include toxins similar to heavy metals and PCBs. My wager is that this may occasionally most commonly have an effect on the pool all the way down to Braddock.
In the end the turbidity will relax and the Monongahela River will succeed in a brand new commonplace.
How a lot will the dam removing have an effect on the Mon at Duck Hole? We’ll have to observe and notice.
Location of Locks and Dam 3 is at the Google map beneath. Learn extra in regards to the venture at The Waterways Magazine.