Draft EIS_072312.pdf - Middle Fork American River Project ...

20120723-4002 FERC PDF (Unofficial) 07/23/2012
Table 3.3.5-3. Whitewater boating opportunities on the peaking reach (Source:
PCWA, 2011a, as modified by staff).
Reach Class a
Tunnel Chute Run (Middle Fork
American River from Indian Bar Rafter
Access to Ruck-a-Chucky recreation
area)
Mammoth Bar and Murderer’s Bar runs
(Middle Fork American River from
Ruck-a-Chucky recreation area to
Murderer’s Bar)
Confluence Run (North Fork American
River from confluence with Middle
Fork American River to Oregon Bar)
204
Boatable
Range
(cfs)
Optimum flow
(cfs)
II–IV 800–2,500 1,000–1,250
I–II 500–2,500 800–1,200
II–III 350–2,500
800–1,500
a American Whitewater website,
http://www.americanwhitewater.org/content/River/state-summary/state/CA/.
Oxbow powerhouse is typically operated to follow daily power demand and to
provide whitewater boating flows in the peaking reach. Except during high-flow times of
the year, releases from the Oxbow powerhouse cause daily fluctuations in flows in the
peaking reach of up to about 900 cfs (about 75 to 1,025 cfs). Daily peaking duration can
be short (a few hours) or long (most of the day). In addition, the magnitude of off-peak
flow can vary and there can be multiple peaks and declines in flow over the day. The
peaking reach is boated privately and commercially; however commercial boating
accounts for the vast majority of use (17,110 out of 25,683 boaters in 2007). During the
summer (June through Labor Day), project operations at Oxbow powerhouse are
voluntarily modified 18 to accommodate commercial whitewater boating which require
high flows (about 900+ cfs) for a minimum of about 3 hours, typically beginning at 9:00
a.m. to 10:00 a.m. If normal peaking operations at Oxbow powerhouse (based on power
demand) are not projected to provide high-flow releases within the whitewater boating
window (e.g., 9:00 a.m. to 12:00 p.m.), then the Oxbow powerhouse release pattern is
modified to accommodate whitewater boating.
18 The existing license requires PCWA to coordinate with California Department
of Parks and Recreation and commercial whitewater boating representatives to make
voluntary releases from Oxbow powerhouse that are suitable for whitewater boating from
June through Labor Day.