March 25, 2020 -COVID-19 Update: Pacificorp has issued this press release  announcing closures of most of their recreation areas.  Information on the status of their recreation facilities are available at

P3 fish screen and canal

Prospect No. 3 is one of four hydroelectric developments operated by PacifiCorp in the Rogue River basin. The other three developments, Prospect Nos. 1, 2, and 4 are operated under FERC License No. 2630 and are not subjects of this application. Each of the four developments diverts water from a separate tributary to the Rogue River. Prospect No. 3 diverts water from the South Fork to the Middle Fork Rogue River. The project boundary includes land within the Rogue River-Siskiyou National Forest.

Project Name Prospect No. 3
LIHI Certificate No. 109
LIHI Certificate Term
December 31, 2014 –
December 31, 2019Extended to May 31, 2020
Owner PacifiCorp Energy
State Oregon
Location Located at river mile 10.5 on the South Fork of the Rogue River, Oregon.
Installed Capacity 7.2  MW
Average Annual Generation 35,050 MWh
Facility Type Run-of-river
FERC No. P-2337 issued 2019, expires 2059

Prospect No. 3 is a run-of-river project which received a new 40-year FERC license on September 27, 2019. With the new license minimum flows were increased from 10 cfs to 30 cfs from March through October, and 20 cfs from November through February (or inflow if less) and new ramping rates of 0.2 ft/hour were imposed.  Additional protection, mitigation, and enhancements measures are being implemented under the new license.

Project works include a 172-foot-long, 24.7-foot-high concrete diversion dam including weir boards, with a 98-foot-long ogee crest. The South Fork dam creates a 1-acre impoundment with a gross capacity of 10-acre-feet at an elevation of 3,375 feet. The project has a fish ladder located at the diversion dam and a fish screen and downstream fish-bypass system are located on the canal just below the diversion intake.

The project has a 15,894-foot-long conduit system that consists of two concrete-lined canal sections, a 66-inch-diameter, approximately 1-mile-long woodstave penstock, a 5-foot-wide by 6.5-foot-high, 699-foot-long, concrete lined horseshoe type tunnel, a canal to penstock transition with a 473-foot-long side channel spillway, and a 66- inch to 68-inch-diameter, 3,274-foot-long, riveted steel penstock.

The Prospect No. 3 powerhouse contains one vertical Francis generating unit with a rated capacity of 7.2 MW. A concrete tailrace structure approximately 20 feet by 20 feet by 5 feet extends from the powerhouse. An 887-foot-long  siphon can divert up to 150 cfs water from the Prospect No. 3 tailrace to the Middle Fork canal, which empties into the North Fork Reservoir that is part of the Prospect Nos. 1, 2, and 4 project.   Prospect No. 3 generates an annual average of 35,050 MWh transmitted via a 6.8-mile- long, 69-kV transmission line to the regional grid.


P3 powerhouse

Prospect No. 3 Powerhouse

Prospect No. 3 Penstock


Certification History

March 24, 2020: The Low Impact Hydropower Institute (LIHI) has received a complete recertification application from Pacificorp Energy for the Prospect No. 3 Project located on the South Fork of Rogue River in Jackson County, Oregon. The complete application can be found below.

LIHI is seeking comment on this application. Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc.) will be most helpful, but all comments will be considered. Comments may be submitted to the Institute by e-mail at with “Prospect No. 3 Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Avenue, Suite 6, Lexington, MA 02420. Comments must be received at the Institute on or before 5 pm Eastern time on May 23, 2020 to be considered. All comments will be posted to the web site and the applicant will have an opportunity to respond. Any response will also be posted.

July 27, 2015: LIHI Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has determined that the Prospect No. 3 Hydroelectric Project (FERC No. 2337) continues to meet the LIHI Certification Criteria. The effective certification date for the Prospect No. 3 Project is December 31, 2014 for a five (5) year term, which will expire on December 31, 2019, with the following  condition:

Satisfied 2019. Condition 1.  The current FERC license for the facility will expire in early 2019, before the end of the term of the new LIHI certificate.  LIHI certification does not imply any judgment or recommendation on what the terms of future FERC licenses should be.  If the facility owner receives a new FERC license before the end of the new LIHI certification, the facility owner shall provide LIHI with notification of that fact within 30 days of the relevant FERC Commission Order and describe all differences between the pervious and new licenses that are relevant to the LIHI criteria.  LIHI staff will review those differences and decide whether any changes will be required to the current LIHI certificate.  LIHI reserves the right to modify its certification of the facility to maintain consistency with future FERC requirements and the agency recommendations therein.

February 3, 2015: The Low Impact Hydropower Institute received a complete and timely application for a new term of Low Impact Certification for the Prospect No. 3 Hydroelectric project on November 20, 2014.  Please see the application files below.

July 8, 2013: The Prospect No. 3 Hydroelectric project has been certified as low impact for a five-year term, effective December 31, 2009 and expiring December 31, 2014.

May 22, 2013: UPDATE: PacifiCorp Energy submitted an application for the certification of its Prospect No. 3 Project on December 21, 2009. It was posted to the website on December 31, 2009. An application review was submitted on September 15, 2010, and the report concluded that the Prospect No. 3 project complied with all criteria except for Water Quality. This failure was due to the project’s absence of a 401 Water Quality Certification, but as a result of recent approval from ODEQ, the certification for Prospect No. 3 will likely be considered at the LIHI Governing Board meeting in June 2013.

April 12, 2013: ODEQ issued a letter concluding that data in the report verify water associated with Prospect No. 3 meets the state water quality numeric criteria.

December 31, 2009: PacifiCorp Energy submitted an application for the certification of its Prospect No. 3 Hydroelectric Project. Application was posted to website and public comment period was opened.


2020 Recertification

2014 Recertification

2009-2013 Certification