Boyne Valley Water Initiative
Originally proposed in 1965, the Boyne Valley Water Initiative (BVWI) consists of a new dam to be constructed on the Boyne River, downstream of the town of Treherne in the Municipality of Norfolk Treherne. The dam would store 24,300 acre-feet = 29, 973 dam3 (1 dam = 1000 m3 ~= 1 acre-foot) of water to increase the supply available for municipal, irrigation and other uses in the region, particularly during periodic droughts or low summer flow periods. The dam could also assist in reducing flood flows in the reach between Treherne and Stephenfield Reservoir.
The new storage would provide greater flexibility in the management of the limited water resources in the watershed and surrounding region. Firm flows in the watershed are already fully allocated. Given the water shortages experienced in the past, this increased supply and management flexibility is required under existing hydrologic conditions, and becomes even more critical under any modified hydrologic conditions that may arise as a result of climate change.
The new reservoir would be filled using flow stored during the spring freshet of the Boyne River (once sufficient flows have been released to assist in filling up the Stephenfield Reservoir located downstream) as well as water diverted from the Assiniboine River. Diversions would occur only during periods when the Assiniboine water flows significantly exceed the current and future allocations downstream of the diversion intake either during spring freshet in April to May, when much of the Assiniboine flow in this reach is diverted to Lake Manitoba for flood protection, or during the late fall when the Shellmouth Reservoir is drawn down for winter.
This feasibility study will re-analyze the Treherne Dam proposal in light of water harvesting infrastructure within the context of climate change.
Southern Manitoba's vulnerability to climate variability and change was highlighted by recent drought events in 2017. In early April, spring flooding along the Boyne River forced Carman's water treatment plant to shut down due to high turbidity levels. The other situation occurred in early June as farmers were spraying their fields. The increased demand for water left the region struggling to supply local communities with their water requirements. Additionally, the Boyne River has reached its maximum license capacity for summer/firm flow conditions, which is of specific concern for the supply of potable water in the region. However, spring runoff flow retention could alleviate shortages but only if significant investments in water storage were made.
There is also the possibility that the frequency, intensity and duration of droughts may increase due to anthropogenic climate change, stressing the need for robust drought adaptation strategies.
The qualitative analysis (with the help of the Province of Manitoba records and the work being done by the Prairie Climate Centre) of past, present and future (potential) experiences of drought and other climatic extremes is helping to advance knowledge of how best to respond and adapt to such conditions, and how this might vary between different locations, sectors and communities. It has become increasingly clear that more effort is needed to address the changing environment and climate, by shifting from notions of ‘drought-as-crisis’ towards a more proactive approach that acknowledges the variable availability of water and that multi-year droughts should not be unexpected, and may even become more frequent.
Exacerbating the issues of climate impacts on water security and supply is the complexity of the agricultural industry, regional economics, and demographic changes (decreasing/growing populations) which are currently occurring across most rural communities. The social and economic issues facing rural communities are not just a product of drought or climate change – to understand them as such would underestimate the extent of the problems and inhibit the ability to coordinate the holistic, stakeholder-based approach needed for successful climate change adaptation in rural communities.
A full re-analysis of the Treherne Dam project in the current policy and environmental context is justified as it represents a class of water harvesting infrastructure key to successful climate adaptation, and it could also be a model for a larger green infrastructure investment program for the Prairies.
The new storage would provide greater flexibility in the management of the limited water resources in the watershed and surrounding region. Firm flows in the watershed are already fully allocated. Given the water shortages experienced in the past, this increased supply and management flexibility is required under existing hydrologic conditions, and becomes even more critical under any modified hydrologic conditions that may arise as a result of climate change.
The new reservoir would be filled using flow stored during the spring freshet of the Boyne River (once sufficient flows have been released to assist in filling up the Stephenfield Reservoir located downstream) as well as water diverted from the Assiniboine River. Diversions would occur only during periods when the Assiniboine water flows significantly exceed the current and future allocations downstream of the diversion intake either during spring freshet in April to May, when much of the Assiniboine flow in this reach is diverted to Lake Manitoba for flood protection, or during the late fall when the Shellmouth Reservoir is drawn down for winter.
This feasibility study will re-analyze the Treherne Dam proposal in light of water harvesting infrastructure within the context of climate change.
Southern Manitoba's vulnerability to climate variability and change was highlighted by recent drought events in 2017. In early April, spring flooding along the Boyne River forced Carman's water treatment plant to shut down due to high turbidity levels. The other situation occurred in early June as farmers were spraying their fields. The increased demand for water left the region struggling to supply local communities with their water requirements. Additionally, the Boyne River has reached its maximum license capacity for summer/firm flow conditions, which is of specific concern for the supply of potable water in the region. However, spring runoff flow retention could alleviate shortages but only if significant investments in water storage were made.
There is also the possibility that the frequency, intensity and duration of droughts may increase due to anthropogenic climate change, stressing the need for robust drought adaptation strategies.
The qualitative analysis (with the help of the Province of Manitoba records and the work being done by the Prairie Climate Centre) of past, present and future (potential) experiences of drought and other climatic extremes is helping to advance knowledge of how best to respond and adapt to such conditions, and how this might vary between different locations, sectors and communities. It has become increasingly clear that more effort is needed to address the changing environment and climate, by shifting from notions of ‘drought-as-crisis’ towards a more proactive approach that acknowledges the variable availability of water and that multi-year droughts should not be unexpected, and may even become more frequent.
Exacerbating the issues of climate impacts on water security and supply is the complexity of the agricultural industry, regional economics, and demographic changes (decreasing/growing populations) which are currently occurring across most rural communities. The social and economic issues facing rural communities are not just a product of drought or climate change – to understand them as such would underestimate the extent of the problems and inhibit the ability to coordinate the holistic, stakeholder-based approach needed for successful climate change adaptation in rural communities.
A full re-analysis of the Treherne Dam project in the current policy and environmental context is justified as it represents a class of water harvesting infrastructure key to successful climate adaptation, and it could also be a model for a larger green infrastructure investment program for the Prairies.