What is considered a "high" flowrate for a waterway?
What is considered a "high" flowrate for a waterway?
(OP)
Hello all,
I previously posed this in another area, but I quickly found that this area is a better forum for such a question...
Can someone please explain/provide information of what they would consider a low flowrate, a medium flowrate and a high flowrate for a waterway in cfs?
I was told that a creek has a 10 year flow rate of 250 cfs, and I am trying to get an idea of how fast that is in my head as I do not deal with waterflows every day.
thanks to all who respond.
I previously posed this in another area, but I quickly found that this area is a better forum for such a question...
Can someone please explain/provide information of what they would consider a low flowrate, a medium flowrate and a high flowrate for a waterway in cfs?
I was told that a creek has a 10 year flow rate of 250 cfs, and I am trying to get an idea of how fast that is in my head as I do not deal with waterflows every day.
thanks to all who respond.





RE: What is considered a "high" flowrate for a waterway?
You could use Manning's equation to determine the approximate flow rate at any given depth.
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: What is considered a "high" flowrate for a waterway?
Columbia River - 400,000 cfs - top width 1,800 feet - 26 ft deep might be considered "large"
Provo River - 1,200 cfs - top width 47 feet - 4 ft deep might be considered medium
your creek is probably considered small
all three might have the same velocity...
RE: What is considered a "high" flowrate for a waterway?
where:
Q = flowrate in cu. feet per second
V = velocity in feet per second
A = area in square feet
Realistically, the best way to calculate the velocity would be using Manning's Equation (as PSmart suggested) or, if you don't really care for hand calculations, you can use FlowMaster (by Bentley Systems) or any other simliar software).