ojmGA
Civil/Environmental
- Mar 18, 2024
- 1
I’m designing a small detention pond that will outflow into existing drainage system. The system runs for 1500 feet with 6 curb-inlets and outfalls into an existing detention pond. The line that I must tie into is an 18”. I will install a new curb-inlet where my 18” outlet pipe will tie in. The system transitions from 18” to 42” pipe. I’m using the crown of the 42” pipe at existing detention pond as my HGL control.
The resulting 100 Yr HGL looks very good (well below the curb-inlets)
until we get to the proposed new curb/inlet and on to the OCS. It jumps to 4 ft above proposed inlet and 4.5 feet above the 100 year water level for the proposed detention pond. The cause of course is the small 18” pipe that I have to tie into.
My question: is that level acceptable for the 100Yr HGL ?
The 25Yr HGL is 6” below the Inlet,
and very near the 25 Yr water level.
Any comments welcomed.
jmGa
The resulting 100 Yr HGL looks very good (well below the curb-inlets)
until we get to the proposed new curb/inlet and on to the OCS. It jumps to 4 ft above proposed inlet and 4.5 feet above the 100 year water level for the proposed detention pond. The cause of course is the small 18” pipe that I have to tie into.
My question: is that level acceptable for the 100Yr HGL ?
The 25Yr HGL is 6” below the Inlet,
and very near the 25 Yr water level.
Any comments welcomed.
jmGa