Category Archives: Yellow Falls GS

Yellow Falls Generating Station, Mattagami River

Yellow Falls

Yellow Falls

Yellow Falls Generating Station (formerly Island Falls) is a 2-unit “run-of-river” hydroelectric generating facility being developed by Boralex with a nameplate capacity of 16 megawatts (MW) located on the Mattagami River, approximately 18 km south of the town of Smooth Rock Falls, Ontario.

The intake and powerhouse that will house the two 8-MW turbine-generator units will be combined in a close-coupled arrangement near the west bank of the river. A spillway equipped with three vertical-lift, fixed roller gates and one set of stop logs will be built adjacent to the powerhouse.

Two sections of dam, one on the east side of the powerhouse and one on the west, at approximately 15 metres high will be built. A substation that steps up the generation to 115 kilovolt (kV) will be built at the end of the westerly dam. Approximately 21 kilometres of 115 kV overhead transmission line that mainly routes along Red Pine Road will be installed to connect the generating facility to existing Hydro One 115 kV circuit H9K.

As part of the project, approximately 14 kilometres of existing access road will be upgraded, and 7 km of new road will be built along with two new bridge installations. The gross head of the facility will be approximately 15 metres. The total discharge of the plant at capacity is approximately 160 cubic metres per second.

It is estimated that this facility will be capable of producing 87,000 megawatt-hours of renewable energy annually; enough electricity to power approximately 12,000 average Ontario homes.

Location: Smooth Rock Falls, Ontario
River System: Mattagami River
Nameplate Capacity: 16.0 MW
OPA Contracted Capacity: 16.0 MW
Developer: Boralex
Technology: Run-of-the-river, hydroelectric
Turbines: Two 8-MW turbine-generator units
Target Commercial Operation Date: Q3 2016

Project Progress
as of December 31, 2013

  • Stakeholdering activities continued
  • Design and procurement activities continued


Boralex –