Kettle Generating Station

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For a high level overview of this and other hydro projects see Hydroelectric Development in Northern Manitoba.

Background[edit]

Studies in the 1960s and early 1970s envisioned a four phase development at Kettle Rapids and downstream, namely the sites at Kettle Rapids, Long Spruce Rapids, Lower Limestone Rapids and Gillam Island to harness the abundant hydroelectric potential of the Nelson River.

The first phase of development was initiated in the spring of 1966 and included the following components:

  • a generating station at Kettle Rapids;
  • a High Voltage Direct Current (HVdc) transmission line from Kettle Rapids to the City of Winnipeg;
  • control works to divert the Churchill River into the Nelson River via the Rat and Burntwood Rivers; and
  • control works to regulate the outflow of Lake Winnipeg into the Nelson River.

The long range view was that the Kettle Generating Station (GS) would be the first in a series of generating stations intended for the lower Nelson River.

Location[edit]

The Kettle GS is located at the site of the former Kettle Rapids on the lower Nelson River. It is approximately 4.4 mi (7 km) west of the Town of Gillam and 1.9 mi (3 km) upstream from the Canadian National Railway's (CNR) river crossing near the town. The distance from the City of Winnipeg to the Kettle GS is over 460 mi (740 km) by air.

Map 1: Kettle Generating Station General Arrangement

Project Components[edit]

Principal Works[edit]

The station spans a total of 0.9 mi (1.5 km) across the Nelson River and consists of a close-coupled intake/powerhouse with 12 turbine generator units (units), concrete wing walls, non-overflow dam, two main earthfill dams (north and south), ancillary dams and dykes, and an eight bay gated spillway (Photos 1 and 2, Map 1). A series of dams and dykes flank the Nelson River to reduce the extent of flooding from the project (Photo 3).

Photo 1: Kettle Generating Station
Photo 2: Kettle Generating Station - View from the South Shore
Photo 3: Datnau Dam Dyke
Photo 4: Operating Spillway at Kettle Generating Station

Project Data[edit]

  • Turbine generator units:
    • Type: 12 vertical shaft fixed blade propeller turbines
    • Capacity: 1220 MW (63rd Annual Report, March 2014)
  • Powerhouse:
    • Length: 1200 ft (365.76 m)
    • Waterfall drop (head): 101.0 ft (30.8 m)
    • Discharge capacity: 155,900 ft3/s (4,415 m3/s)
  • Main dams (North and South dams):
    • Length: North Dam = 2,400 ft (730.0 m); South Dam = 1,000 ft (300.0 m)
    • Maximum height: North Dam = 164.0 ft (50.0 m); South Dam = 167.0 ft (51.0 m)
  • Spillway:
    • Number of bays: 8
    • Length (8 bays): 394.0 ft (120.09 m)
    • Discharge capacity: 360,210 ft3/s (10,200 m3/s)
  • Reservoir/forebay elevation:
    • Full supply level (maximum): 463.0 ft (141.122 m)
    • Normal minimum operating forebay elevation: 453.0 ft (138.074 m )
    • Flooded Area: 85.2 mi2 (220.6 km2)

Supporting Infrastructure[edit]

Main access to the region during construction was by the Hudson Bay Railway line (now HBR; CNR at the time) which had a rail station and siding at the Town of Gillam. A 1.0 mi (1.6 km) rail spur was added near the generating station site. A new 4.4 mi (7 km) permanent gravel road was built from the Town of Gillam to the generating station site and the Radisson Converter Station site to link these projects to the community. The Town of Gillam was not connected to the provincial road network until well after completion of the project. The community had a permanent airstrip since 1967 that was utilized as required.

Generation Outlet Transmission[edit]

The electricity generated at the Kettle GS is transmitted to the Radisson Converter Station which is located approximately 1.5 mi (2.4 km) south of the generating station. At the Radisson Converter Station the electricity is converted from alternating current (AC) to direct current (DC) and is transmitted via the High Voltage Direct Current (HVdc) Bipole I transmission line to the Dorsey Converter Station, by the City of Winnipeg. Once at the Dorsey Converter Station the electricity is converted back to AC before being fed into the provinces southern distribution system.

Construction[edit]

Principal Works[edit]

Beginning in the spring of 1966 construction was started on the access road, main camp, construction power station, and the Stage I cofferdam (Photo 5). Construction materials were sourced from locally available sites. Rock came from quarries upstream of the project site in the forebay area, granular materials came from the Gillam Esker east of the project site, and impervious materials came from local borrow areas.

Photo 5:Kettle Generating Station During Construction

Most of the construction workforce lived on site in camp while a small percentage lived and commuted from the Town of Gillam on a regular basis.

Clearing of Kettle’s forebay was undertaken immediately upstream of the powerhouse with impoundment beginning in 1970. A dam at the outlet of the Butnau River along with a series of dykes along 15 mi (24 km) of the south shore of Stephens Lake (neer Moose Nose Lake) were built to contain flooding from the backwater effect from Kettle’s forebay. The Butnau River is a tributary of the Nelson River whose flows were cut off by one of these earthfilled dams at Stephens Lake. As a result, it was diverted into the adjacent Kettle River which flows north downstream of the Kettle GS into the Nelson River. To achieve this a 2.5 mi (4 km) long, 60 ft (18 m) wide channel was built from Cache Lake to the Kettle River to redirect the Butnau River.

The first unit went into service in December 1970 and by the time the generating station was officially opened in June 1973, seven units were in service. The twelfth and final unit was up and running in November 1974. With the completion of all its units the Kettle GS became Manitoba Hydro’s largest generating station in its system. It maintained this status for nearly two decades until the Limestone Generating Station came into full service in 1992. Development of the Kettle GS resulted in Moose Nose Lake forming part of the Kettle forebay which was subsequently named Stephens Lake.

Construction Infrastructure[edit]

A temporary construction camp and associated work areas were established near the site. In 1966 and 1967, a 79 mi (127 km) 138 kV transmission line was built from the Kelsey GS to the site of the future Radisson Converter Station to provide power for upcoming construction activity. Short tie-ins from this line provided electrical power to the Kettle GS construction area and to the nearby Town of Gillam, which was about to undergo a major expansion.

Operations[edit]

Access: Access to the Kettle GS is by road via PR 280 from the Town of Gillam or the City of Thompson. The Kettle GS can also be accessed by boat from the Town of Gillam.

Workforce: The station has approximately 30 to 35 staff comprised of the following: operating staff, maintenance staff (electrical, mechanical, utility), support staff (administration, stores) and supervisory staff. The station is fully staffed every day between 0700h and 1800h. Outside of normal business hours the Kettle GS is controlled by operating staff at the Long Spruce GS. The Kettle GS operating staff are on call and would be dispatched in case of an alarm or to initiate spill. Additional support and technical services are located in the nearby Town of Gillam.

Public Safety: The Kettle GS has a portage around the site and the following public safety features:

  • downstream boat launch area;
  • a water release siren is used before adjusting discharge to warn the public in the area;
  • life rings are provided on the spillway;
  • fencing is used as a barrier to dangerous areas; and
  • warning signs are provided (in English and Cree) at sites to warn the public of: dangerous swift moving waters, steep drop off, overhead power lines, stay off Ice, falling ice, slippery rocks, and rapidly changing water conditions.

Water Regime: The Kettle GS is operated in a daily and weekly cycling pattern that allows Manitoba Hydro to match energy production to consumption patterns. For more details on operating parameters and their effects on the water regime (see Water Regime, Section 4.3.4.3).

License: Manitoba Hydro operates the Kettle GS in accordance with a Province of Manitoba Water Power Act licence. For further information, see the Manitoba Government Water Power Licensing website at: http://www.gov.mb.ca/waterstewardship/licensing/water_power_licensing.html

References[edit]

Manitoba Hydro & the Province of Manitoba, December 2015, Regional Cumulative Effects Assessment Phase II: Part II Hydroelectric Development Project Description in the Region of Interest. Retrieved April 1 2016 from, https://www.hydro.mb.ca/regulatory_affairs/rcea/pdf/rcea_phase2_part_ii_hydroelectric_development_project_description.pdf