## Stream Flows

The rate of flow of a creek, river or flood is measured by quantity over time. This is often referred to as discharge: “the rate at which a volume of water passes a given point in a given amount of time”.

There are two basic units of water measurement from a water management perspective.  For water that is in motion, cubic feet per second (cfs) is the unit of measure.  For water that is stored or impounded, the acre-foot (af) is how water is measured.

For rafting, we need water to be in motion so we use cubic feet per second (cfs) to take measurements.

## What does it mean?

A cubic foot is like a box of water measuring one foot by one foot by one foot. The USGS defines cubic foot per second (cfs) as “the flow rate or discharge equal to one cubic foot of water per second or about 7.5 gallons per second.”

### Fun Facts:

* 1 cubic foot = 7.4805 gallons.
* 1 cubic foot per second = 7.4805 gallons flowing by a particular point in 1 second.
* 1 cfs = 1.983 acre-feet per day = 646,320 gallons = 2447 cubic meters of water.
* 1 cfs is equivalent to 448.8 gallons of water flowing per minute.
* 1 cfs will produce 724 acre-feet of water per year.
* 1 cfs = 38.4 miner’s inches of water.