W. A. C. Bennett Dam facts for kids

Quick facts for kids W. A. C. Bennett Dam
The W. A. C. Bennett Dam, taken from the viewpoint
Location within British Columbia
Location	Hudson's Hope, British Columbia, Canada
Coordinates	56°01′00″N 122°12′02″W / 56.01667°N 122.20056°W / 56.01667; -122.20056
Construction began	1963
Opening date	1968
Owner(s)	BC Hydro
Dam and spillways
Type of dam	Embankment dam
Impounds	Peace River
Height	186 m (610 ft)
Length	2,068 m (6,785 ft)
Spillway capacity	9,205 m3/s (325,100 cu ft/s)
Reservoir
Creates	Williston Lake
Total capacity	74 km3 (60,000,000 acre⋅ft)
Surface area	1,761 km2 (680 sq mi)
Power station
Turbines	10
Installed capacity	2,907 MW
Capacity factor	58.9%
Annual generation	15 TWh (54 PJ)

The W. A. C. Bennett Dam is a huge hydroelectric dam located on the Peace River in northern British Columbia, Canada. It is one of the tallest earth-fill dams in the world, standing 186 metres (610 ft) high. Building the dam started in 1961 and finished in 1968.

The dam creates Williston Lake, also known as Williston Reservoir. This lake is fed by the Finlay, Parsnip, and Peace rivers. It is the third largest artificial lake in North America and the biggest freshwater body in British Columbia. Williston Lake stretches 250 kilometres from north to south and 150 kilometres from east to west.

The dam cost about $750 million to build. It was the largest project of its kind in British Columbia at the time. The dam was named after Premier W. A. C. Bennett. He had a big vision for the project. The lake was named after his trusted colleague, Ray Williston. The Gordon M. Shrum Generating Station at the dam makes a lot of electricity. It can produce over 13,000 GWh each year. This supplies more than a third of British Columbia's power. When it was built, the powerhouse was the largest in the world. It is still the biggest power station in British Columbia. It is also the third largest hydroelectric project in Canada.

Building the dam and the lake brought many jobs and economic chances for British Columbia. This included work for the new power company, BC Hydro, and for many workers. However, it also cost a lot of money. For example, clearing the land for the reservoir cost $5 million.

The dam's construction also caused some problems. One issue was the big negative environmental effects it had. When Williston Lake was created, 350,000 acres of forest land were flooded. This led to a loss of different plants and animals, known as biodiversity. It also affected rights to minerals and timber.

Another problem was that people lived on the land before it was flooded. About 40 to 50 residents, including members of the Tsay Keh Dene First Nation, had to move. This displacement caused difficult social changes for them. They lost their land, which had supported them, leading to feelings of isolation and challenges in their community. A BC Hydro consultant even said in 1977 that the lake's isolation had serious impacts on the Tsay Keh Dene people's society and culture.

History of the Dam

Why the Dam Was Built

W. A. C. Bennett was the Premier of British Columbia from 1952 to 1972. He wanted to develop British Columbia on a large scale. He believed in using the province's natural resources. Big hydroelectric projects, like the W. A. C. Bennett Dam, were part of his plan. He thought that controlling nature would make British Columbia rich. It would also help the province grow with more industries and modern cities.

Bennett's ideas about hydroelectric power were part of a belief called "high modernism." This idea suggests that big government projects can improve society. While these projects can bring benefits, they can also have downsides. For example, the Peace River project changed the environment. It caused some people to live in isolation and face challenges. However, these projects also created a lot of cheaper energy for British Columbia. This helped industries grow and created many jobs.

The Two Rivers Plan

Premier Bennett had a plan called the "Two Rivers policy." He wanted to develop the power from both the Peace and Columbia Rivers at the same time. He wanted British Columbia to control its own resources.

At first, Bennett tried to make a deal with an American company to build a dam on the Columbia River. But the Canadian federal government stepped in. They said they controlled international waterways. This meant British Columbia couldn't sell electricity to America for its own profit.

So, Bennett focused on the Peace River. He decided to build a huge dam there, which became the W. A. C. Bennett Dam. He hoped that developing the Peace River would give British Columbia enough power to convince the federal government to let them sell Columbia River electricity to the Americans. This "Two Rivers" plan faced some opposition. Some people thought any electricity from the Columbia River should be for Canada only.

The Two Rivers policy led to the W. A. C. Bennett Dam on the Peace River. It also led to the Keenleyside Dam and Mica Dam on the Columbia River. In 1964, the plan was officially put into action with the Columbia River Treaty. Because of his plan, Bennett successfully pressured the Canadian government. British Columbia was allowed to sell electricity to the Americans for 30 years. This brought in a large payment of US$275 million. The creation of BC Hydro in 1961 was also part of this strategy.

Choosing the Dam Site

Ray Williston, a government minister, suggested turning parts of the Peace and Columbia River basins into power sources. This area, called the "Power Trench," would provide electricity. It would also help control water flow for flood prevention and farming in both the U.S. and Canada.

In 1957, a company identified 12 possible dam sites on the Peace River. One spot, 22 kilometres from Hudson's Hope, was chosen as the best due to its natural shape. Gordon Shrum, a physics professor, studied the costs of building dams on both rivers. He concluded that building on the Peace River would be cheaper. This was especially true if a public company, like a government-owned one, was used because they could get lower interest rates.

Building the Dam

When the W. A. C. Bennett Dam (then called Portage Mountain Dam) got the green light, the first step was to clear the land for the future lake. This was a huge job. The Forest Service Branch completed it on a tight budget of $5 million. When the water rose, hundreds of thousands of cut trees floated on the lake's surface.

Early construction involved building a temporary dam, preparing the ground, and making it watertight. Workers also dug out a solid base for the dam. Over time, 55 million cubic yards (42 million cubic metres) of rock and dirt were moved from a nearby glacial area using conveyor belts. This material was used to build the dam, which mostly relies on gravity to hold it together.

Once finished, the W. A. C. Bennett Dam became one of the largest earth-filled dams in the world. It is 183 metres tall, 800 metres wide, and two kilometres long. It also has one of the biggest hydroelectric power stations. Its 10 generating units are located deep underground, about 150 m (490 ft) below the surface. The main powerhouse is called the G.M. Shrum Generating Station. It was designed to look like a giant transformer, showing its function and modern 1960s style.

The project was seen as a big success, especially since it was in a remote area. Gordon Shrum, head of the new BC Hydro company, managed the construction. BC Hydro was created by the government to help fund the project with lower interest rates. When Shrum took over in 1961, the project was already a year behind schedule. But with a hands-on approach, it was officially completed in late 1967. The first generators started working in 1968. The project finished on time and within budget, though more construction continued until 1980.

Over 20 unions worked on the dam. They had 10-year contracts that prevented lockouts or strike action. This helped the project stay on schedule. Workers came from all over North America, Europe, and even Japan. They lived in temporary camps near the site. Much of the work was inside the dam, which was cramped and full of fumes. Sadly, 16 men lost their lives building the dam.

During construction, the Portage Mountain lookout was built early on. This allowed tourists to watch the dam's progress.

Upgrades and Improvements

From 2009 to 2012, units 6 to 8 of the dam were updated. This increased the plant's power capacity by 90 megawatts. Unit 7, the last of these, started working on November 29, 2012.

Units 1 to 5 have also been completely updated and improved. These upgrades make the first units installed at G.M. Shrum more reliable. They also increase the power each unit can generate by as much as 17%.

Economic Benefits

For British Columbia

In the 1950s, British Columbia's economy relied heavily on natural resources. This made it sensitive to changes in global demand. However, British Columbia was still a popular place to live in Canada. It had the highest income per person, leading to a good standard of living.

Premier W. A. C. Bennett believed that unused natural resources were wasted. He pushed for developing the huge hydroelectric power of the Peace River. Today, the W. A. C. Bennett and Peace Canyon facilities produce about 35% of British Columbia's total electricity.

For BC Hydro

In March 1962, Premier Bennett introduced a plan to create BC Hydro. This new company would help him carry out his Two Rivers Policy. At first, BC Electric didn't want to buy power from the Peace River project because cheaper power was available elsewhere. So, the government merged BC Electric with another company, the BC Power Commission. This created the new BC Hydro. BC Hydro became responsible for building the dam, powerhouse, and related structures.

For Local Communities and Workers

Building the dam and creating Williston Lake brought many jobs. Workers found employment with BC Hydro or its contractors. These workers included local First Nations people, other residents, and immigrants. One contractor, the Forest Service Branch, was paid $5 million to clear the area for Williston Lake, which was 80% covered in timber.

At its busiest, the project employed 3,500 workers. Many moved to the area for the job and settled near the dam. Hudson's Hope, a frontier town, saw its population grow from 800 to over 5,000 in 1968. It then dropped to under 1,500 by the early 1980s. About 2,000 workers also lived in a camp close to the dam site.

Social Impacts

Effects on First Nations Communities

For some people, especially Aboriginal groups, the environmental changes from the dam meant big challenges. Their traditional lands became unlivable. The British Columbia government offered a settlement. They bought 14,000 acres of land, including timber and mineral rights, for $1.7 million. They also bought out about 150 individuals and families. About one-third of these were members of the Tsay Keh Dene First Nation.

Beyond relocation, Aboriginal hunting and fishing grounds around Fort Grahame and Finlay Forks were greatly affected. Many fish species, as well as mountain caribou and muskrats, became unavailable. These changes made First Nations groups more dependent on government help. Between 1965 and 1970, government social assistance to Aboriginal groups near the dam increased by 300 percent. The serious impact of the dam is well-documented in a research paper by Daniel Sims, a Tsay Keh Dene First Nation member.

More recently, in October 2008, the Kwadacha First Nation reached a settlement with the British Columbia government and BC Hydro. This was for damages caused during the dam's construction and operation. The settlement included a $15 million payment and annual payments of $1.6 million.

The effects on the Tsay Keh Dene First Nation were shown in The Scattering of Man (DƏNE YI’INJETL), a 2021 documentary film.

Effects on Local Residents

When the government decided to dam the Peace River, it started many social changes in the nearby communities. These changes were positive for workers who came for jobs. But they were negative for residents who lived there before the dam.

Premier W. A. C. Bennett imagined growing communities when he planned the dam. In 1964, his vision seemed to come true with the "instant town" of Mackenzie. Thousands found jobs there with BC Forest Products. This company spent $60 million on a "forestry complex" to process timber from the cleared land.

However, some residents who owned land were forced to sell their homesteads for small payments. For example, one farmer with a thousand acres was offered only $28,000 by BC Hydro. But for local residents of European background, full-time jobs were easier to find due to the dam project.

Environmental Impacts

Downstream Effects

The W. A. C. Bennett Dam brought great economic potential. But for the environment around it, the experience was not as good. Many environmental changes have happened since its construction. The dam has caused less natural changes in the Peace River's water levels downstream. This has changed the plants and animals in the area.

It has also been blamed for changes in the Athabasca Lake and Peace River area, known as the Athabasca Delta. This part of the river lost a lot of water. The flood plains of the Peace-Athabasca Delta started drying up. Floods that used to happen every two or three years stopped. These floods used to refresh the wetlands and their diverse life. As a result, the delta had lower water levels. This affected both the landscape and the aquatic life.

After Williston Lake was completed in 1971, water coverage in the delta dropped by 38 percent. Twenty years later, wetlands had decreased by 47 percent. Less water flow led to toxins and sediments building up downstream. This lowered the water quality. Fish also faced changes. Fewer channels were available for walleye to reach spawning grounds. Young fish also struggled to reach nursery areas, risking their ability to reproduce.

Dinosaur Lake was created directly downstream of the W. A. C. Bennett Dam. This happened when the Peace Canyon Dam was completed. The Peace Canyon Dam was built to generate more hydroelectricity using water from the W. A. C. Bennett Dam. Today, it is a popular place for camping in British Columbia. The Site C dam was proposed as another dam downstream, similar to the Peace Canyon Dam.

Upstream and Williston Lake Effects

The area upstream of the dam experienced many environmental changes due to the flooding. Creating the lake flooded a huge area of forest land. This drowned a lot of wildlife and drastically changed the landscape. The reservoir became 250 kilometres long from north to south and 150 kilometres wide from east to west. Two farmers asked for money from BC Hydro because the higher humidity affected their crops. The water was no longer flowing, but standing still. This led to cooler temperatures and more fog.

Changes happened not only in the air but also in the water. The reservoir affected aquatic life that used to live peacefully in the river. Rivers and lakes support different species. So, some fish thrived in the lake, but others could not survive in the new environment. Mountain whitefish, rainbow trout, and Arctic grayling especially saw their numbers decline. Some species did well, and it's thought there are more fish in the basin today than before the reservoir. However, these fish have mercury levels that show they are not entirely healthy.

High levels of mercury have been found in the lake. This is because decaying plants and trees release mercury into the water. The mercury is then eaten by tiny organisms and moves up the food chain. In 2000, British Columbia issued a warning about eating bull trout and dolly varden fish. This was because of their high mercury content.

The creation of the reservoir also cut off a caribou migration route. This, along with other industrial development in Peace River Country, severely impacted the southern mountain caribou populations. The Burnt Pine herd became locally extinct by 2013. By 2016, five out of six other herds were at risk of local extinction. In the Klinse-Za herd, only 16 animals remained by 2014.

Visitor's Centre

The W. A. C. Bennett Dam Visitor Centre is located near the dam. It overlooks the Williston Lake Reservoir. The centre has exhibits about the dam, how hydroelectricity works, and the area's natural and cultural history.

See also

In Spanish: Presa W. A. C. Bennett para niños

• List of largest power stations in Canada
• List of conventional hydroelectric power stations
• List of generating stations in BC