View Full Version : Out flow vs discharge

01-22-2014, 10:29 PM
What is the difference or explain to me DISCHARGE & OUTFLOW when looking at TVA water discharges on their website.

For example at Tim's Ford hourly discharge is 100 while average outflow is 700

How much water is running down the river?

Thanks Hammy

01-22-2014, 11:05 PM
My understanding is it is just a difference in terms. As many times you will find the outflow is same as discharge. But outflow can take into account other sources of water other than what is discharged. I am sure someone will articulate it better than me. But discharge usually means what is being controlled and outflow is the flow of the river that might have other water input besides what is being discharged. I am sure others will weigh in on this.


01-23-2014, 08:26 AM
I might try to find a phone number and call TVA and see if they can explain it.


01-23-2014, 09:13 AM
My guess is that average hourly discharge is the per hour discharge in cfs while the average outflow is the average over a 24 hr peroid. If you look at the previous 48 hrs of discharge, the value jumps up to 3800 cfs at times when the generator is on. So if you have 16 hours of 100 cfs and 8 hours of 2000-3000 cfs, that would average out to about 700-800 cfs per hour over the 24 hr day.

For fishing trip planning purposes, the hourly discharge is what you need to pay attention to.

01-23-2014, 09:56 AM
Thanks Jimmy. That all makes sense to me.


01-23-2014, 08:49 PM
Also remember that Tim's Ford frequently sluices water through the spill gates in addition to running water through the turbines for hydropower generation.

01-23-2014, 08:55 PM
Well if you look at the 48 hour report, it does not appear to be doing that. If Im reading it correctly.