5. Managing Water Supply and Demand

There are many diverse pressures and challenges to consider in water supply and demand planning and management. These include (but are not limited
 to) population growth, community and economic development, infrastructure and asset management, and the need for environmental stewardship.

It is also becoming increasingly important to consider the impacts of climate change when planning and managing water supply and demand. Climate change is having, and will continue to have, far-reaching implications on all aspects of water management.

In Canada, water allocation and licensing decisions are the responsibility of the provincial government. In BC, these responsibilities are administered by the Ministry of Forests, Lands, and Natural Resource Operations (MFLNRO), which issues water licences. MFLNRO balances responsible use, community health and safety, maintaining terrestrial and aquatic ecosystems and other priorities.

Once water licences are issued, the management of water supply and demand becomes largely the responsibility of those that hold the licenses including local governments, First Nations, and other community-scale water suppliers. These groups develop and manage community water supplies as well as treatment and distribution systems. Local and First Nations governments also have roles in developing and implementing various water-related plans and programs. These include strategies to conserve water and manage demand and also to mitigate the impacts of drought. Local governments, First Nations and other water suppliers also participate in, or lead, multi-sector water and watershed planning initiatives. We all use water, so as citizens, farmers, ranchers and countless other businesses and industries that use water, we all share in the responsibilities to manage our water use.

Types of Water Supply & Demand Plans

This section of the guide profiles 4 specific types of plans:

Why Plan for Water Supply and Demand?

There are many pressures on watershed that are placing – and will continue to place – pressures on water supply and demand. Common pressures throughout BC include population growth, land use practices, community and economic development, climate change and other changes in ecosystems (such as the Mountain Pine Beetle infestation). Therefore the extent of existing water use requirements and the hydrological characteristics of watersheds are important considerations in managing supply and demand.

BC communities are adopting a wide range of strategies to manage water. Water planning processes can help communities understand challenges by improving knowledge about water supplies and demands including sharing the allocation of water across various human activities and also ensuring that environmental needs (i.e. instream flows) are also met. For a comparison of three water management techniques (supply side, demand management, and the “soft path” approach) see the 2005 POLIS publication At a Watershed¹. These approaches can be especially helpful in managing community conflicts during times of water shortages and drought. The process of water management planning also serves to increase awareness in a community, and stakeholders will be more likely to promote responsible water management practices in their homes, businesses and neighbourhoods.

Water supply, demand and allocation management are primarily about balancing water use. These include human water uses for domestic, agricultural, hydroelectrical, commercial and industrial consumption, as well as natural system water uses to support healthy ecosystems, particularly fish and fish habitat. Good water management can allow for human use without compromising the environment. Desired outcomes of water planning may include:

Challenges and Pressures

Water supply is a significant issue in many communities in BC and around the world. Water supply is particularly important in regions where supplies may be limited, storage capacity is limited, and/or water demand is nearing or exceeding water supply. The characteristics of water supply and demand are community specific, and depend on many factors. The following are a few examples of topics and factors to illustrate the range of water supply and demand challenges experienced in communities across BC.

Total and Seasonal Population Growth
Some communities and regions, such as the Lower Mainland, the east coast of Vancouver Island and parts of the Thompson-Okanagan region, are experiencing significant population growth. This growth puts increased demand and pressure on existing water supplies, particularly where supplies are already stressed. Communities that are heavily influenced by seasonal tourism may have unique challenges in managing seasonal fluctuations in demand for domestic use. For example, in Tofino, the population grows 10-fold in the summer because of the significant amount of tourism in the area. This is the same time when the creeks are at their lowest flow-levels.

Drought Conditions
When communities are faced with water shortages or drought conditions, conflicts between different water users may emerge or increase. For example, in 2003, Summerland’s water supply was substantially depleted, which resulted in a significant conflict between the provision of water in streams to ensure fish survival and the provision of water for farmers and food production. In extreme cases, senior levels of government may intervene in water allocation issues. In the spring of 2010, the BC Ministry of Environment used its authority under the Water Act, to change the regulated amount of diversion and use of water, and invoked priority rights in the Chimney Lakes area.

Surface and Groundwater Interactions
Conflicts may also arise between users of surface water and users of groundwater because these sources are often closely linked. For example, excessive withdrawal of groundwater may reduce groundwater contribution to instream flows, particularly in the dry summer months when streams, aquatic ecosystems and other users of surface water are most vulnerable to low flows. Also excessive surface water withdrawal can lead to groundwater sources being depleted, as some aquifers are recharged from surface supplies such as rivers.

Aging and Inadequate Infrastructure
Many BC communities are also facing challenges associated with aging infrastructure, such as inadequate supply capacity or leaky distribution systems. Water infrastructure is very expensive to replace and upgrade, and often water conservation is viewed as a preferable alternative to increasing capacity. Because of the wider infrastructure deficit throughout BC and Canada, water infrastructure – for water supply and distribution, wastewater treatment, drainage and flood protection – has to compete with other types of infrastructure for limited capital funds.

Climate Considerations
Climate change is impacting, and will continue to impact, many aspects of water supply and management in BC. Reduced annual and seasonal precipitation, reduced snowpacks, loss of glaciers, changing surface and groundwater hydrology, increased drought and increased demand for irrigation are just a few examples. These and other climate-related impacts should be addressed in plans that aim to consider medium to long-term pressures on water supply and demand. The plans should develop solutions for dealing with those pressures. See sections 3 and 9 of this guide for information, tools and resources about climate change impacts on water, related community vulnerabilities and risks, as well as considerations about how climate impacts can be managed through adaptation and water and watershed planning.