Interpreting some hydropower data. What does DSF mean in this context?

Question

This is the historical feed of the Keystone dam for October 2014:

• www.swt-wc.usace.army.mil/chartbin/KEYSOct14.shtml

Here is the real time feed:

• www.swt-wc.usace.army.mil/ops_hydropower/KEYShydro.html

I am having trouble understanding the "Releases DSF" Power/Total columns. What do these mean? I understand that DSF is day-second-feet but that is a unit of volume NOT flow rate. The real-time feed shows the flow rate in CFS (cubic feet/second). The dam is rated at around 70 MW. Do you think that the column in the historical data is mislabelled as Power when it should be Energy (MWh)?

I understand that Power = Height of Dam x Flow Rate x Efficiency and this makes sense in the real-time feed. However, I am having trouble reconciling the historical data with the real time data.

Bottom line: I want to know the power / energy generated at the dam historically and in real time.

Answer 1

I think the DSF releases are both measures of releases. Neither is a measure of power. They are both a measure of the amount of water released, in day-second-feet, as you say.

The total column is the measure of the total amount of water released (in DSF). The power column is the amount of water released in order to generate power (in DSF). The difference between those two numbers is the amount of water (in DSF) released down the spillways (rather than to generate power), as part of overflow prevention, maintenance, or other activity.

On the realtime feed, the column labelled power looks like mean power to me in MW: the dam rating is 70MW, and the power column maxes out at 70.267, so that does indeed look like MW. So that's the average over the quarter-hour. Multiply by 0.25 to get MWh.

_{footnote rant: Feet? Seriously? Feet? Who uses feet? What's wrong with these people?}