The Lewis River Hydroelectric Projects - PacifiCorp

Lewis River Interpretive & Education Plan
However, power generation is not the only factor. Ultimately, the operation of
the Lewis River Facilities is a complex choreography of water storage, power
generation, and water release. The basic needs driving the system are:
• Electricity generation needs (this includes meeting the needs of the
consumers via the grid, maintaining sufficient water behind the dams to
support spinning reserves, and maximizing profit/minimizing loss based
on fluctuating electricity costs).
• Environmental needs (PacifiCorp is required as part of its license to
maintain at least a minimum flow rate in the Lewis River below Merwin
Dam during all times of the year for fish spawning, incubation and rearing.
• Recreation needs (PacifiCorp provides recreation sites for the public, and
minimum reservoir heights are required to make these recreation sites
usable).
• Flood management needs (this consists primarily of maintaining “storage”,
or reserve space, in the reservoirs to buffer high input or “runoff ” during
the winter).
• Maintenance needs (the company must take into account regular and
unscheduled maintenance needs in planning water releases).
In addition to all these parameters, PacifiCorp water managers must also factor
in the future, including weather forecasts and energy cost estimates to create
daily water release schedules. These provide hour-by-hour plans for operation of
the river system and generation.
Daily water release schedules are provided to the main control center (which
controls facilities not only on the Lewis River but also on the Rogue, Klamath,
and other rivers) which has the responsibility of operating the units to meet the
schedule.
Working 8-hour shifts, 24 hours per day, control room operators implement
the schedules (the actual control work is done by computers, but it can be
done manually if necessary). Because of constantly changing conditions and
electricity demands, schedules may need to be changed, with some generators
brought online earlier or later than scheduled, or some plants run that were not
scheduled at all. A typical workday for a control room operator includes multiple
phone calls to and from site operators, adjustment of schedules, and constant
monitoring of facility readouts.
Sea Reach Ltd • 146 NE yamhill Street • Sheridan, OR draft 3 • November 2008 • page 75