Bureau of Reclamation Banner
Reclamation Home             Reclamation Offices             Newsroom             Library             Projects & Facilities

Grand Coulee Dam: Third Power Plant Overhaul Project

Project Update | Tentative Schedule | Complete Projects

Transcript PDF 57 kb

On the western hillside above Grand Coulee Dam, workmen in neon green t-shirts straddle a partially built transmission tower hundreds of feet high. The crew, barely visible against a maze of power lines and steel structures, are building six new towers that will support 18 power lines coming from the Third Power Plant across the Columbia River.

The new towers are part of a year-long effort to install new 500-kV overhead transmission lines and high voltage towers. The lines stretch from the powerplant, across the Columbia River, over the visitor center area, and then proceed uphill to existing lines that transfer power into the Bonneville Power Administration’s regional grid network. (Video by Kirsten Strough, Visual Information Specialist)


The six generating units in the Third Power Plant (TPP) have been in service since the mid-1970s. Age-related wear is beginning to create problems which have resulted in increased power outages and reduced reliability. The overhaul project will ensure continued operation of the powerplant and allow Reclamation to provide a reliable source of hydroelectric power to the region.

Reclamation is preparing for the overhaul outages by identifying specific repair needs, performing detailed analysis, performing design work, and seeking contracts for work to be completed prior to overhaul. A considerable amount of the Planning and Design work is being accomplished in partnership with Architect-Engineering companies under contract with Reclamation.

These efforts will result in improved reliability of equipment that is needed to support the overhaul, will identify ways to minimize outage durations, and will reduce the likelihood and magnitude of increases to outage time.

Project Summary
Photo Gallery | Base Scenario Animation
Third Power Plant Generating Units Overhaul Activities EA Addendum
Third Power Plant Generating Units Overhaul Activities EA & FONSI
Grand Coulee's Third Power Plant 500-Kilovolt Transmission Line Replacement Project FONSI
Grand Coulee's Third Power Plant 500-Kilovolt Transmission Line Replacement Project EA (BPA)
Project Update - Third Power Plant (TPP) Status Report – November 08, 2013
500 kV Cable: The contract was awarded to Wilson Construction for $18.5M. The new overhead lines were commissioned in December 2012 and the oil‐filled cables have been removed. Spacers on the jumpers in the 500kV spreader yard still need to be installed and will be installed in an ongoing basis until April 2014 when conveniently planned with an existing and corresponding scheduled outage. The project was substantially completed in December 2013 when transmission was first achieved.

Shaft Seals: The $1.6M contract was awarded to SM seals in June 2010. The seals have been received, inspected and stored awaiting installation during the G‐22, G‐23 and G‐24 mechanical overhaul.

Mechanical Overhaul of Units G-22, G-23, G-24: The $102M contract was awarded to Andritz Hydro, Inc. Onsite work began in March 2013 and is scheduled for completion by December 2017. Unit G‐24 has been disassembled and refurbishment has begun on the various components. The project has experienced issues requiring a three month extension to the Contract; mechanical components found to have significant wear and require additional refurbishment include wicket gates, draft tube concrete surfaces, and outer head cover.

Overhaul of Units G-19, G-20, G-21: The uprate study of units G19‐21 has been completed. Meetings with BPA Customers and various decision makers has started to occur. A decision on uprating is anticipated from BPA sometime in early 2014, at which time the scope, schedule, and budget for the work on these units will be further defined. A Project Value Planning Study will commence in June
Tentative Schedule
Activity Start Finish
Overhaul Units G22-24 March 2009 December 2017
Design March 2009 January 2010
Procurement January 2010 May 2011
Construction March 2013 September 2017
Overhaul G-24 March 2013 September 2014
Overhaul G-23 September 2014 March 2016
Overhaul G-22 March 2016 September 2017
Overhaul Units G19-G21 January 2018 December 2025
Design January 2014 TBD
Procurement TBD TBD
Construction January 2019 December 2025
Overhaul G-19 TBD TBD
Overhaul G-20 TBD TBD
Overhaul G-21 TBD TBD
Complete Projects
Material Storage Building (MSB): The $5M project was awarded to Graham Construction.  The building is complete.
NEPA for MSB and TPP Overhaul: The NEPA was completed and the EA has been issued.
TPP Crane Control Replacement: The $11M project was awarded to Dix, Inc. for cranes Ederer 2 (275 Ton) and Ederer 4 (50 Ton) inside the powerhouse and the Forebay Gantry Crane (275 Ton) outside of the powerhouse. The project is complete.
Fixed Wheel Gate Chamber Modifications:  The $4M project was awarded to Knight Construction, Inc.  The project is complete.
TPP Elevator Overhauls: The project was awarded to ThyssenKrupp, Inc. for $1.5M.  The project is complete.
Excitation Systems:  The project was awarded to ABB, Inc. for $17M.  The project is complete.
Governor Upgrades:   The project was awarded to American Governor, Inc. for $1.5M.  The project is complete.
Transformer Replacement (G19 & G20):  The $26M contract was awarded to Gardner-Zemke, Inc.  The project is complete.
Brian Clark
Project Manager
Grand Coulee Power Office
(509) 633-9693



Last Update: February 11, 2014 12:14 PM