Disadvantages
Although hydroelectricity is arguably one of the cleanest and safest alternative energy sources, there are two main disadvantages that go along with it.
Ecosystem Damage and Erosion
The larger the dams, the larger the reservoir needed to hold enough water to power it. This floods the land behind the dam, which can lead to severe ecosystem loss. Although in Canada this hasn't been a major issue, in areas of high erosion and steep cliff sides, this can be a major source of landslides.
Secondly, there has always been a problem of fish getting caught in the dam especially in salmon spawning areas in BC. Fish ladder research has been an active part of making dams more eco-system friendly. Still, this is a problem in many fish species on the west coast of Canada.
Siltation and Deposition
Dams don't like sediments. It can clog up the penstock and turbine. Silt and sediment can also fill a reservoir thus, reducing the volume of water to use for power production and reducing the ability to control floods. This can also lead to complete dam failure in rare cases (Patrick James, H. Chansen, 1998).
On rivers with heavy sedimentation such as the Fraser River in BC, these hydroelectric dams can lose a lot of their efficiency. The lack of sediments being let through the penstock can also lead to erosion of the soil downstream, since it isn't being built up by the constant flow of sediments. This is a danger to the city of Richmond and Delta in the Lower Mainland of BC, since these areas are built on the sediment deposit of the Fraser River.
Ecosystem Damage and Erosion
The larger the dams, the larger the reservoir needed to hold enough water to power it. This floods the land behind the dam, which can lead to severe ecosystem loss. Although in Canada this hasn't been a major issue, in areas of high erosion and steep cliff sides, this can be a major source of landslides.
Secondly, there has always been a problem of fish getting caught in the dam especially in salmon spawning areas in BC. Fish ladder research has been an active part of making dams more eco-system friendly. Still, this is a problem in many fish species on the west coast of Canada.
Siltation and Deposition
Dams don't like sediments. It can clog up the penstock and turbine. Silt and sediment can also fill a reservoir thus, reducing the volume of water to use for power production and reducing the ability to control floods. This can also lead to complete dam failure in rare cases (Patrick James, H. Chansen, 1998).
On rivers with heavy sedimentation such as the Fraser River in BC, these hydroelectric dams can lose a lot of their efficiency. The lack of sediments being let through the penstock can also lead to erosion of the soil downstream, since it isn't being built up by the constant flow of sediments. This is a danger to the city of Richmond and Delta in the Lower Mainland of BC, since these areas are built on the sediment deposit of the Fraser River.