Blog |

Flows drop after a long pull on Anderson Ranch Water

Posted by admin on September 7, 2012 | No Comments

South Fork Boise River flows downstream of Anderson Ranch Dam

The Bureau of Reclamation began turning down the dial on the boating flows after the end of the Labor Day weekend.

By the end of Tuesday September 4th flows dropped from 1,850 cfs to 900 cfs. On Wednesday the 5th the flows were at 600 cfs.

Summer boating flows lasted longer and were slightly higher than the typical 1,600 cfs. In fact, the 1,800 cfs flow seems to be a “new normal.”

So why did flows stay higher through Labor Day? Continue Reading…

Tagged flows, storage

South Fork Boise Rainbows: More Wild than Native

Posted by admin on July 8, 2012 | No Comments

Map with pie charts showing extent of hybridization across the Boise River Basin

An article in a recent issue of the North American Journal of Fisheries Management takes a look at the South Fork Boise River wild trout fishery in the context of genetic background of the redband/rainbow trout residing in the upper Boise River basin.

Authors Helen Neville (Trout Unlimited Boise office) and Jason Dunham (US Geological Survey, Corvallis, OR) studied the hybridization of the redband trout due to the historic stocking of hatchery-raised coastal rainbow trout in the South Fork Boise River until the late 1970s, and compared genetic information on the South Fork trout with samples of trout from tributaries in the North and Middle forks of the Boise River.

It was the 2008 fish sampling genetic study that provided the basic information for the genetic analysis, and ultimately this report. Using the genetic analysis plus fish stocking records dating back several decades the authors concluded the following: Continue Reading…

Tagged fishing, Genetics

Opening Weekend 3,000 cfs; now down to “normal”

Posted by admin on June 1, 2012 | No Comments

After an opening weekend of fishing season where the South Fork was running at 3,000 cfs the flows have dropped to 1,700 cfs, ending May with a normal boating flow.

Some may complain about flows at 3,000 cfs or higher, but these water volumes are necessary for a healthy river. The flow spike at 6,000 cfs should have helped bring more changes to side channels and river banks, perhaps rearranging some sections of river bottom, routing sediment and creating new holding areas for fish and bugs.

Anderson Ranch Dam is 94 percent full and inflow is very close to the outflow. In fact, it looks like Anderson Ranch will not completely fill this year. Ironic, after a winter with the most stored water in the system. But it was a complicated run-off, and Continue Reading…

South Fork at 6,000 cfs: A Top Ten Rating

Posted by admin on April 29, 2012 | No Comments

On Friday April 27, 2012, releases from Anderson Ranch Dam hit 6,000 cfs. This is a flow quantity rarely seen on the South Fork Boise River. Based on records dating back to 1943 (seven years before the dam’s completion) here’s the top years where peak flows got nearly to, or exceeded, 6,000 cfs.

Since 1943 here are the years where peak flows were 6,000 cfs or better

Tagged flows

Lots of Water for 2012

Posted by admin on April 1, 2012 | No Comments

Snowpack can and probably will continue to accumulate in the Boise mountains but it’s time for a snapshot where things stand for the 2012 conditions. We have lots of water, both in the reservoir at Anderson Dam and in the mountains above. We will start with the mountains: Continue Reading…