Bridge River

Bridge River recreation site

The Bridge River is a mid-sized stream approximately 120 km long, flowing south-east from the snowfields of the Coastal Mountains and joining the Fraser River near Lillooet.

The Bridge River hydroelectric complex consists of three dams and stores water for four generating stations. The system uses Bridge River water three times in succession to generate 492 megawatts, or 6 to 8 per cent of British Columbia's electrical supply.

BC Hydro operates recreation areas on Seton Lake Reservoir (Naxwit Picnic Area, Seton Beach, Seton Viewpoint, Seton Dam Campground and the Bridge River Picnic Site) and on Carpenter Reservoir (Gun Creek campground, pictured above).

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For details about the area, follow the links below:

Access and directions

Need directions? View a map of BC Hydro recreation areas, including specific directions to Bridge River picnic site, Gun Creek campground, Seton Dam Campground and Naxwit picnic area.

Bridge River powerhouses

Work on Powerhouse No.1 was postponed until 1946 due to the depression and war years. However, growing power requirements of the post-war era gave the project great urgency.

The building was rushed to completion and the first generator was installed in1948. Three more generators were added at intervals until 1954. The plant's total output of 180 MW was the largest source of power in the province at that time. While a second tunnel was being bored to carry water from Carpenter Reservoir, work on Powerhouse No. 2 commenced.

Four generators were installed by the end of 1960. Water for the turbines of both powerhouses flows from the tunnels under Mission Mountain into steel penstocks, which drop a vertical distance of 329 m (1,078 feet) down the hillside.

Bridge No.1 has four penstocks-one for each turbine. Bridge No. 2 has two penstocks, which split into four just before they enter the powerhouse.

The Bridge River Powerhouses have a maximum generating capacity of 480 MW and an average generating capability of 2670 GWh per year - more than enough to supply the City of Surrey.

Carpenter Reservoir

Terzaghi Dam

When Bridge Powerhouse No. 1 on Seton Lake Reservoir was completed and ready for water in 1948, a low temporary dam was built across the Bridge River to direct the water flow into the penstocks. Later, with the construction of Bridge Powerhouse No. 2, Terzaghi Dam, 55 m (180 feet) high, was built about 2.4 km (1.5 miles) downstream. Completed in 1960, this dam impounded 23,725 cubic metres (838,800 acre-feet) of water in Carpenter Reservoir at an elevation 651 m (2,136 feet). The dam was renamed in honour of Dr. Karl Terzaghi, founder of the science of soil mechanics and chief consultant for the design and construction of the dam.

Bighorn Creek campground

The Bighorn Creek campground is permanently closed due to flood risks. In May 2003, a significant debris flood from Bighorn Creek descended on the campground and destroyed five of the 15 campsites.

The flood carried about 7,000 cubic meters of mud and rock on to the site. This was the second flood event in five years. Bighorn Creek upstream of the campground is unstable and more debris flows can be expected in this area in the future.

The Gun Creek campground is located within the historic Bridge River Valley. Facilities at this 13-site camp-ground include pit toilets, picnic tables and fire rings. Fishers can try their luck in Gun Creek.

During the early 1900s pioneers staked mineral claims and formed mining communities throughout this region. The remains of one of these mining towns lie beneath Carpenter Reservoir.

Bill Davidson, the President of Minto Gold, planned and built the townsite in 1934, following the start-up of the Minto Gold Mine. For several years Minto Gold was one of the most productive mines in the valley. However, a flood on Gun Creek in 1950 left the town inundated and severely damaged. 

After the completion of the Terzaghi Diversion Dam in 1954, the waters of Bridge River were backed up and Carpenter Reservoir was created, flooding the town of Minto. For detailed information on Minto and other Bridge River mining communities, we recommend a trip to the Bralorne Pioneer Museum.

Lajoie Dam

The westernmost stop on our tour is the Lajoie Dam. Construction of the dam was carried out in two steps. First, a low earthfill structure was completed in 1949 to store water for the Bridge plants.

Second, the dam was raised to its current height of 87 m (287 feet) in 1955. Completion of these steps impounded 15,130 cubic metres (534,300 acre-feet) of water at elevation 750 m (2,460 feet) to form Downton Reservoir.

The reservoir was named in honour of the pioneer surveyor Geoffrey Downton who, in 1912, first recognized the enormous potential for power development utilizing the drop in elevation between the Bridge and Seton River systems.

A powerhouse with one generator was completed at the foot of the dam in 1957, with a capacity of 22 MW and an average generating capacity of 170 GWh per year - more than half the electricity needed to supply all the homes in the city of Kamloops.

Find out about recreation area closures and restrictions.

Safety

Hydroelectric production creates special concerns for visitor safety. Dam intakes cause strong surface and underwater currents. Reservoir users should not swim or boat near dam discharge facilities, power canals and penstock areas. Carpenter and Downton Reservoirs have numerous underwater hazards. Swimmers and boaters should watch for stumps and floating debris, particularly in shallow water along the shoreline. Obey all posted signs.

Visitor information, guidelines

  • Pets must be on a leash at all times. Pets are prohibited on Seton Beach from April to October.
  • Open fires are not allowed in the day-use areas. Some tables are equipped with metal stands to support barbecues. Follow the campfire safety rules.
  • Overnight camping is permitted in designated sites only. No overnight camping is available at Seton Beach, Seton Viewpoint or Naxwit Picnic Area.
  • Trails are closed to all motor vehicles.
  • The Bridge River Picnic Site, located at the western end of Seton Lake Reservoir, is located between Seton Portage and Shalalth. Road access is difficult and visitors should be aware of local conditions whether arriving via the Mission Mountain Road from Lillooet or the Highline Road from D'arcy.

History and hydroelectric operations

The Bridge River is a mid-sized stream approximately 120 km long, flowing south-east from the snowfields of the Coastal Mountains and joining the Fraser River near Lillooet.

The Bridge River hydroelectric complex consists of three dams and stores water for four generating stations. The system uses Bridge River water three times in succession to generate 492 megawatts, or 6 to 8 per cent of British Columbia's electrical supply.

Hydroelectric development of the system began in 1927 and was completed in 1960. Its waters (Downton Reservoir) initially pass through the Lajoie Dam and powerhouse and are then diverted through tunnels and penstocks from Carpenter Reservoir to the two powerhouses on Seton Lake Reservoir.

Finally, the water flows from Seton Lake Reservoir, through the Seton Powerhouse and into the Fraser River.

Hydroelectric operations seasonally change water levels on Carpenter and Downton Reservoirs. From July until early November water levels rise due to spring runoff and from late November to June water levels decline as energy demands are met.

Seton Lake Reservoir water levels remain relatively constant throughout the year.

BC Hydro balances the need for power with the requirements for fisheries, environment, flood control and recreation when managing its reservoirs.

Environmental requirements are considered as part of BC Hydro's day-to-day work. BC Hydro meets or exceeds legislation and works closely with regulating agencies to minimize impacts on fisheries resources.

Dams and generating stations have impacts on fisheries and BC Hydro is working to reduce these impacts through research, capital projects (such as the fish ladder at Seton Dam) and operating initiatives (conducting fish salvages when flows change to avoid fish stranding).

Hydroelectric facilities are managed in a way that is sensitive to the communities in which BC Hydro operates. In the Bridge River area, BC Hydro has regular meetings with local communities, including First Nations, to exchange information and manage common issues.

BC Hydro operates recreation areas on Seton Lake Reservoir (Naxwit Picnic Area, Seton Beach, Seton Viewpoint, Seton Dam Campground and the Bridge River Picnic Site) and on Carpenter Reservoir (Gun Creek campground).