TCFS--Thousand Cubic Feet per Second
TCFS is a measure of water flow in which one
thousand cubic feet of water passes a measuring point in a second. You may
convert from flows measure in MAF/yr to flows in TCFS by multiplying by
1.38. For example, a flow of 10 MAF/year corresponds to a flow of 13.8 TCFS
or 13,800 cfs (cubic feet per second).
In his Preface to The Snake River: Window to the West, Palmer (1991)
uses this measure to help us think of creeks and rivers of different sizes:
| 100 cfs | could be considered a creek |
| 300 cfs | in a small channel will float a canoe and might be as wide as a four lane highway |
| 1,000 cfs | a flow of 1 TCFS would be a small river |
| 2,000 cfs | a flow of 2 TCFS can float large rafts even in a wide riverbed and might be seen in summer flows at Grand Teton National Park in Wyoming |
| 5,000 cfs | a flow of 5 TCFS or more would be a large river |