The Isabella Reservoir Pool Restriction

At the November 21, 2014 public meeting in Kernville regarding the Isabella Dam project, the Corps posted the following slide (dated November 17, 2014) indicating the pool restriction would be in effect from late 2020 until June 01, 2021:

However, the Corps' Final Environmental Impact Statement, released in October 2012, states the pool restriction will be in effect during "a four-to-six-month window from Fall 2020 to early Spring 2021." (Final EIS at pp. 2-5, 2-10, 2-13, 2-24, 3-16, 3-30.) 

Spring begins in late March, so KRB analyzed the historical April 01 storage data for the Isabella reservoir. The result is that over the last 50 years, storage in the reservoir on April 01 has averaged 204,827 acre-feet.

If, contrary to November 17 slide above, "early Spring" is when the Corps is targeting to lift the pool restriction, then around April 01, 2021 storage in the reservoir will be at 72,237 acre-feet, or less.

The reservoir has a storage minimum. 30,000 acre-feet are required to remain in the reservoir for lake recreation. Thus, while the April 01 average storage available for river release has been 174,827 acre-feet, on or around April 01, 2021 only 42,237 acre-feet will be available. The pool restriction accordingly limits useable water to 24% of the historical average.

Fast forward to the summer of 2021. The watermaster has never released boatable flows with storage in the 72,000 acre-feet range. There is no guarantee the watermaster will release inflows from that season's snowmelt at boatable levels during the summer of 2021, as opposed to using those inflows to fill the reservoir. There may not be sufficient inflows to release at boatable levels should the Southern Sierra experience drought the previous winter. And, of course, project delays could keep the pool restriction in force beyond early Spring 2021. 

KRB continues to believe the Isabella Dam project's pool restriction will unavoidably damage the 2021 summer boating season on the Kern below the reservoir, and the Corps should mitigate that damage with a regime of "bubble" releases.

KRB Comments on Isabella Project updated

We found the missing four years of storage data for the Isabella reservoir. Here's the full result. And here's our updated comments. 

The USACE project mandates that storage on June 01, 2021 be capped at 72,237 acre-feet.

Over the last 50 years, the average storage in the reservoir on June 01 has been 302,904 acre-feet.

The reservoir has an "unusable" minimum of 30,000 acre-feet.

Thus, the project means useable storage on June 01, 2021 will be at 15% of average. (42,237/272,904.) The snowpack will have been substantially, if not fully, depleted. And the watermaster has never provided boatable flows with 70-some thousand acre-feet of storage. Thus, the project means there will be no summer boating season on the Lower Kern in 2021 — and perhaps a year or two after that if there are substantial project delays or if the project is followed by a season or two of drought. 

This is the adverse effect on whitewater boating the project entails. The Corps should mitigate it, in our opinion, with some regime of "bubble" rec releases. 

KRB's comments to USACE regarding rec mitigation for the Isabella Dam project

Last week, KRB sent its comments to the U.S. Army Corps of Engineers regarding mitigation for the Isabella Dam project's adverse effects on whitewater boating on the Kern below the reservoir.

Our primary request is for USACE to require the watermaster provide us "bubble" rec releases in return for the enormous private benefit this public project confers on his clients. 

KRB asks that boaters email the Corps to express (1) concern about the adverse effects the project will entail in 2021 (no summer season on the Lower Kern) and (2) support for some regime of bubble releases as mitigation — or boaters can simply email the Corps and express support for the comments submitted by Kern River Boaters. 

The Corps is in the process of finalizing its final recreation report on the project, so email these two addresses soon:

isabella@usace.army.mil

Hunter.Merritt@usace.army.mil

Edison asks to be excused from its Form 80 rec filing requirements on KR1

FERC requires its hydroprojects to report every six years on project-related recreation by means of "Form 80." Southern California Edison has applied for exemption from Form 80 reporting for the Kern River No. 1 project, which dewaters the Cadillacs, Lucas Creek, Richbar & Cataracts runs.

KRB brought this to the attention of American Whitewater three-and-one-half months ago, but AW has yet to take any action. So KRB filed this comment in opposition of Edison's request for exemption with FERC yesterday.