Attachment to Low Impact Hydropower Questionnaire
Question 2: Applicant’s name, contact information and relationship to the Facility. If the Applicant is not
the Facility owner/operator, also provide the name and contact information for the Facility owner and
operator.
Answer:
Applicant is:
Clatskanie Peoples Utility District
469 N Nehalem St.
Clatskanie, OR 97016
(503) 728-2163
Applicant is the power purchaser and by agreement with the Owners has the responsibility and
authority to file this application.
The Facility owner/operator is:
Boise Kuna Irrigation District, Nampa & Meridian Irrigation District, New York Irrigation District, Wilder
Irrigation District and Big Bend Irrigation District
c/o Boise Project Board of Control
2465 W. Overland Rd.
Boise, ID 83705
(208) 344-1141
Question 6: Regulatory Status:
Answer: FERC license No. P-4656, licensed March 27, 1989. License expires February 28, 2039. License
is held by the Facility owners. In addition a state water permit for the generation of hydroelectric power
is held by the Boise Project Board of Control for this Facility, water right No. 63-10240.
Question 8: Area occupied by non-reservoir facilities (.e.g. dam, penstocks, powerhouse)
Answer: The reservoir and dam are property of the United States Bureau of Reclamation. The penstocks
and powerhouse occupy a small bench on the south side of the Boise River below the dam. That area is
less than 5 acres. The transmission line is on a Reclamation right-of-way and is owned by Reclamation.
It occupies approximately 26 acres.
Question 9: Number of acres inundated by the Facility.
Answer: This Facility is an add-on to an existing dam and reservoir. The Facility does not have the
ability to inundate any additional lands not already inundated, so the Facility does not inundate any
acres by itself. The area inundated by the pre-existing Bureau Reclamation operations is approximately
3100 acres.
Question 11: Please attach a list of contacts in the relevant Resource Agencies and in non-governmental
organizations that have been involved in Recommending conditions for your Facility.
Answer:
United States Bureau of Reclamation
Pacific Northwest Regional Office
1150 North Curtis Road, Suite 100
Boise, Idaho 83706-1234
(208) 378-5012
United States Fish and Wildlife Service
1387 South Vinnell Way, Suite 343
Boise, ID 83709
(208) 378-5321
United States Forest Service
Boise Field Office
1249 South Vinnell Way, Suite 200
Boise, ID 83709
(208) 373-4227
United States Army Corps of Engineers
Boise Field Office
304 N. 8th St., Room 140
Boise, ID 83702
(208) 345-2155
Idaho Fish and Game
600 S. Walnut
Boise, ID 83712
(208) 334-3700
Idaho Parks and Recreation
5657 Warm Springs Avenue
Boise, ID, 83716
(208) 334-4199.
Idaho State Historical Preservation Office
210 Main Street
Boise, ID 83702
(208) 334-3847
Idaho Department of Environmental Quality
1410 N. Hilton
Boise, ID 83706
(208) 373-0502
Idaho Department of Water Resources
The Idaho Water Center
322 East Front Street
PO Box 83720
Boise, Idaho 83702
(208) 287-4800
Question 12: Please attach a description of the Facility, its mode of operation (i.e., peaking/run of river)
and a map of the Facility.
Answer: The Arrowrock Hydroelectric Facility is a run of river facility with daily shaping allowed in FERC
license. The primary project components include: 1) two 58-inch diameter steel penstocks, 2) a 70-foothigh powerhouse, 3) two 7.5-MW Francis turbine generating units, 4) a 55-foot-wide, 125-foot-long
tailrace discharging into Lucky Peak Lake, 5) and electrical transmission infrastructure including
generator leads, switchyard, and transmission interconnection with the Idaho Power Company system.
A series of ten outlet conduits extend through Arrowrock Dam. Clamshell gates installed on the
downstream end of each conduit are used to control water releases through the dam. There is also an
overflow spillway on the dam which is used occasionally to release water for flood control. The Project
will receive water via two 58-inch diameter steel penstocks that divert flows from the downstream end
of two of the ten existing outlet conduits to the hydroelectric facility. The remaining eight outlet
conduits will continue to discharge directly into Lucky Peak Lake. Therefore, only a small portion of the
water discharged through the dam will be diverted through the turbines.
The powerhouse and tailrace are located on a basalt bench (elevation 3040) immediately downstream
of Arrowrock Dam. The tailrace will be lined with concrete to minimize water leakage and percolation
through the basalt. Water volumes will range from 350 to 810 cubic feet per second per turbine.
Butterfly shutoff valves with flow-through design are being installed on the turbine inlets. A control weir
(approximate elevation 3022) has been constructed at the downstream end of the tailrace to ensure
draft tube submergence.
A map of the Facility on file with FERC is attached.
Question 16: Did the added or increased capacity include or require a change in water flow through the
facility that worsened conditions for fish, wildlife, or water quality, (for example, did operations change
from run-of-river to peaking)?
Answer: Releases from the Arrowrock Dam are made by the Bureau of Reclamation for flood control
and irrigation purposes. The project is allowed to shape the flows that the Bureau of Reclamation
determines to release on a daily basis only. Thus if the Bureau of Reclamation determines to release a
certain amount of water on a particular day, the FERC License allows the Owner to shape as much of
that pre-determined daily release during peak hours as possible. The purpose of this limitation on
shaping was to prevent injury to bass spawning and recreation uses in the downstream reservoir – Lucky
Peak Lake. The Arrowrock Hydroelectric Facility is not a load following or peaking facility. It can only
use what the Bureau of Reclamation determines to release. Because the project flows exceed the
capacity of the Facility between April and August of each year, no daily shaping is expected to take
place. From November to March daily flow shaping is expected to occur only about 10% of the time.
In addition the Facility cannot operate at heads below 70 feet net head and thus cannot operate when
the risk of entrainment of fish is the greatest.
The USFWS issued a Biological Opinion for this project because of the presence of a listed threatened
species - bull trout - in the Arrowrock reservoir. The Bureau of Reclamation previously consulted with
the USFWS on the dam and reservoir operations and received their own Biological Opinion. The USFWS
Biological Opinion for the hydroelectric Facility concluded “the potential for the Project to result in
entrainment beyond that anticipated under Reclamation’s existing operations will not result in effects to
bull trout in Arrowrock Reservoir that could be meaningfully measured, detected, or evaluated.” USFWS
(2008) p. 26.
C. Fish Passage and Protection
2) Historic records of anadromous fish
During historic times, the Boise River was home to some runs of anadromous fish, likely Chinook salmon.
In the 1860s mining began on Mores Creek, a tributary to the Boise, and settlement of the lower Boise
soon followed and the anadroumous fish populations went into decline and disappeared from many
parts of the Boise River system. By the late 1800s dams were in place on the Boise River below
Arrowrock. Arrowrock itself was completed in 1915. Anadromous fish had disappeared from the Boise
River by this time. Since then the Hells Canyon Complex were built on the Snake River and a series of
dams were constructed on the lower Snake and Columbia Rivers. The Lucky Peak Dam was constructed
by the Corps of Engineers as a flood control facility, immediately downstream of Arrowrock dam so that
it backs water up onto the face of Arrowrock dam. It has no upstream fish passage. The NOAA Fisheries
2005 Biological Opinion for the Bureau of Reclamation’s Upper Snake Project, which includes the Boise
River and Arrowrock reservoir operations, stated that Chinook salmon have been extirpated in the
Snake River and its tributaries above Hells Canyon. Thus, by the time the Facility was built in 2008-2010
no anadromous fish occupied the area around the Facility.