Happy New Year! October 1 marks the beginning of a new water year. Water year 2007 will run from October 1, 2006 to September 30, 2007. The reasons we use this off-kilter calendar are practical, if you think about the weather. In many parts of the west, the summer and early fall are usually dry, with little rainfall. In Portland, we can usually count on fall rains starting in October.

 

Comparing precipitation by a water year starting October 1 helps hydrologists predict when peak flows might occur. Peak flows are important for several reasons. The abundant water refills—or recharges—the watersheds. Water fills the Bull Run reservoirs. Steelhead and coho salmon return to spawn when rivers and streams have more water. Farmers use the water to irrigate their crops. Hydoelectricpower the region uses depends on the yearly recharge of water.

 

Early surveyors of the west such as John Wesley Powell understood that measuring water supply according to the water year would help potential settlers understand how much water a watershed could produce. We’ve been using water years since Powell’s landmark exploration of the Colorado River watershed in 1869, and the "water year" is now defined in the U.S. Code of Federal Regulations (Title 43—Public Lands).

 

So, happy New Year!

 

Doug Bloem

Environmental Specialist