There is more water behind Anderson Ranch Dam this year than at this time a year ago.
There is much more water behind Anderson Ranch Dam than in an average year. Usually in the winter the water should be draining from the reservoir but this year and last year the water coming into the pool has been enough to match the 300 cfs outflow.
It’s still the middle of winter and lots more snow needs to pile up in the mountains, but early indications are the snowpack is average or better, but more importantly there is A LOT of water in Anderson Ranch Reservoir. And it’s got to come downstream at some point in 2011.
So for our first update for 2011 we present a state of the river report, looking at the coming water year. Long time South Fork Boise aficionados recall the normal flow regime is 300 cfs in the winter (Oct through March), followed by the 600 cfs for the shoulder season, usually a period in September but also importantly in April and May for the mainstem river spawning. Then during the summer it’s around 1,800 cfs in a steady push of water for downstream irrigation and salmon water budget contributions.
This year looks like it will be different because the water is stacking up, more than in recent years. Here’s what we know so far…
South Fork of the Boise during the salmon fly hatch.
Thinking back to summer, big flows, big fish on dry flies.
The Bureau of Reclamation and the US Geological Survey are teaming up on a study of the South Fork Boise River. Work began in the past few months with the goal of a better understanding of the spawning habitats.
Flows on Sunday were 1,600 cfs. Then on Monday the flows dropped to 1,000 cfs. After less than 24 hours flows dropped to 600 cfs.
Finally some summer temperatures in southwest Idaho!
After the cool, wet May and (most of) June, the summer weather pattern is starting to take hold and the last of the mountain snow is making it way to feed Idaho’s great rivers. And on this blog we watch the upper South Fork Boise River has it has the heavy influence on the releases from Anderson Ranch Dam and the blue ribbon trout stream.
Last weekend snow blanketed the Boise Front with 16 inches recorded at Bogus Basin. Trinity Mountain in the Upper South Fork Boise River picked up about four inches, but it’s the cool weather before and after that has kept more water stored in the mountain snow than in Anderson Ranch Reservoir.
