Posted by: Michael Caswell
« on: May 18, 2022, 10:11:26 am »Sent in by a member -
"Lowering water levels in a dam is done for one of two reasons only. Either to lower the water from known seep locations near the top of the embankment or to reduce OVERALL hydraulic pressure on the structure itself.
Lowering water level by 1 foot reduces pressure by about 9% and since water weight and earthen wall density are both constants of the hydraulic pressure formula, lowering water by 2 feet would simply double that reduction.
So our section of the "Canal pool" needed 9% less pressure to be "safe" and the Glens Falls Feeder needed almost 20% lower dam pressure to insure failure potential was reduced to acceptable levels."
"Lowering water levels in a dam is done for one of two reasons only. Either to lower the water from known seep locations near the top of the embankment or to reduce OVERALL hydraulic pressure on the structure itself.
Lowering water level by 1 foot reduces pressure by about 9% and since water weight and earthen wall density are both constants of the hydraulic pressure formula, lowering water by 2 feet would simply double that reduction.
So our section of the "Canal pool" needed 9% less pressure to be "safe" and the Glens Falls Feeder needed almost 20% lower dam pressure to insure failure potential was reduced to acceptable levels."