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

20120723-4002 FERC PDF (Unofficial) 07/23/2012
• Allow the public access to project waters and adjacent lands for recreational
purposes, unless precluded due to public safety or facility security concerns
(article 17).
• Maintain project-related roads cooperatively with the Forest Service (articles
18 and 19).
• Provide training to employees regarding identification and management of
cultural resources and laws and related procedures for protecting potential
cultural resources if they are discovered during routine operation and
maintenance or construction of capital improvement projects (some aspects of
this measure are voluntary, and others are required by regulations).
2.2 APPLICANT’S PROPOSAL
2.2.1 Proposed Project Facilities
2.2.1.1 Duncan Creek Diversion
PCWA would retrofit the diversion as follows: (1) modify the existing intake
structure into a self-cleaning, wedge-wire intake; (2) construct a buried conduit from the
modified intake to the existing tunnel portal and seal the existing tunnel intake with
stoplogs; (3) install a remote controlled slide gate to control inflow to the tunnel; (4) raise
the dam abutment by 3.5 feet to avoid overtopping during floods; (5) modify the instream
flow outlet to maintain proposed increased instream flows, facilitate bedload transport,
and establish first priority for water flowing into the wedge-wire intake; (6) modify the
existing low-level outlet through the dam for dewatering the diversion pool in addition to
dewatering the wedge-wire intake collection channel (7) implement of security
improvements; (8) install new communications uplinks; and (9) install a self-contained
solar/thermal electric power supply system.
2.2.1.2 French Meadows Dam Outlet Works Modification
PCWA would modify the existing instream flow outlet at the dam to maintain the
proposed increased instream flows.
2.2.1.3 Hell Hole Storage Capacity Expansion and Outlet Works
Modification
To accommodate the Hell Hole development storage capacity expansion and outlet
works modification PCWA proposes to: (1) modify the existing 350-foot-long Hell Hole
dam ogee spillway for the installation of 6-foot-high pneumatically operated steel
spillway crest gates resulting in an increase in storage capacity of about 7,600 acre-feet;
(2) construct a small concrete control building on the east abutment of the dam between
the dam and spillway to provide power (propane powered emergency electric generator
with an outdoor propane tank) for spillway crest gate operation; (3) install a short spur
powerline to provide power for a proposed new control building; (4) construct a new
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