I'm confused with the info I'm receiving on bridge clearance on the Chicago River and would appreciate some clarification.
I've heard that there's this Lockport Pool reference of 576.2 which matches up with the posted height of the bridge. Meaning that if the pool is at this level, then the 20 ft bridge has 20 ft clearance.
Then there's reference to a 2 foot correction which is very confusing and the river gage, equally confusing. And then there's the reference of up stream or down stream, and I have no clue which is which.
Seems like if the Chicago River flows backward down the Mississippi, at some point someone has to add water to the river to reverse the flow.
However, bottom line, how can I be SURE that I'll clear the lowest bridge on the Chicago River, at 17 feet. My air height is 16'4".
I've heard that there's this Lockport Pool reference of 576.2 which matches up with the posted height of the bridge. Meaning that if the pool is at this level, then the 20 ft bridge has 20 ft clearance.
Then there's reference to a 2 foot correction which is very confusing and the river gage, equally confusing. And then there's the reference of up stream or down stream, and I have no clue which is which.
Seems like if the Chicago River flows backward down the Mississippi, at some point someone has to add water to the river to reverse the flow.
However, bottom line, how can I be SURE that I'll clear the lowest bridge on the Chicago River, at 17 feet. My air height is 16'4".