southforkboise.org blog
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The above illustration is from the report Genetic evaluation of population structure and individual movement of rainbow trout in the lower South Fork Boise River and associated tributaries and the report (pdf) is available by clicking on it.
Make plans to attend an open joint meeting of TU and Boise Valley Fly Fishermen on Thursday, November 12, 2009 at the Boise Public Library to see a presentation on the genetic profile of the South Fork Boise River (SFB) fishery as well as hear a panel discussion of agency and angling community perspectives on Southwest Idaho’s greatest fishing water. Doors open at 6:30 p.m. and the program will begin at 7:00 p.m. Enter in the doors on the 8th Street side at the southwest end of the building.
Helen Neville with the TU national science team based in Boise will present her findings based on the laboratory analysis of the genetic information sampled from more than 300 rainbow trout, and compare that information with dozens of wild trout populations in the North and Middle Fork Boise Rivers.
Idaho Fish & Game, the Boise National Forest, Bureau of Reclamation, TU and BVFF worked together in 2008 to sample the SFB fishery and adjacent tributaries to gather genetic information on redband or rainbow trout. The information presented November 12 will provide a foundation by which a conservation strategy for the SFB fishery could be developed.
Contraindications in the Upper Watershed
The first month of the 2010 water year is done and there is one interesting development in the South Fork Boise River. During October the flows upstream of Anderson Ranch Reservoir were higher than last year (see alternating graph above). The blue line (it’s hard to see) was higher through the month owing to the big storm that blew across the northern Rockies in early October. Trinity Mountain supposedly has 25 inches of snow. So, as that snow melted the meter at Featherville recorded a higher flow than October 2008.
A cooler and wetter October actually helped fill Anderson Ranch Reservoir. The amount it trivial compared to a normal spring run-off of snowpack, but today Anderson Ranch has 268,000 acre feet stored about 5,000 acre feet more than at the beginning of the month. Usually October is a month where the 300 cfs flows from Anderson Ranch Reseer starts to pull on the storage. This year it was different.
IDFG crews are on their marking run this week on the South Fork Boise River. They were to complete the first phase during Tuesday and Wednesday, and then come back next week for the recapture run.
See the little blue tick mark, just below the red line? That’s where we are as far as water in Anderson Ranch Reservoir so far this water year (water years start October 1st, just like the Federal Fiscal Year).
We start this water year near the average and pretty well ahead of last year. And the Snotel site at Trinity Mtn. had 25 inches of snow this morning. Much of that should melt this month, and soak the ground pretty well. Good start to the fish and float opportunities in 2010.
Flows drop to 300 cfs
Flows from Anderson Ranch Dam are now at the wadeable 600 cfs.
Anderson Reservoir is draining at the same rate as last year.
Flows should step down at about the same time as last year in the coming weeks. Look for 600 cfs soon.
The Boise River reservoir system overall is carrying more water than at this time last year.
Flows from Anderson Ranch Reservoir are now at the “normal” summer discharge. Anderson Reservoir will now slowly begin to empty, and the drawdown will increase through the summer.
