Is Our Drinking Water at Risk?

Estimated Read Time: 8 minutes.

Climate change, aging infrastructure, development pressures, and community growth all impact our watersheds, which consequently impact our water supply and water quality. The proposed Drinking Water and Watershed Protection Service aims to protect our water through monitoring, planning, and prevention of impacts.

Where does our water come from?

 Drinking water supplies in the CVRD come from either surface water or groundwater which draws water from aquifers – the underground ‘ponds’ of that lie between soil particles and in rock fissures. Some larger communities, such as Duncan, parts of North Cowichan and Cowichan Tribes, as well as areas of Mill Bay and Yellow Point, rely

Graphic of unconfined acquifer
Source: Public Domain

exclusively on groundwater. The major wells in the Duncan area are fed by unconfined aquifers – areas where free-draining gravel extends to the surface. As a region, our water usage can often put a strain on our water resources. Over-pumping from our aquifers can impact our groundwater supply. Aquifers are recharged by infiltration from the surface from rainwater or snow melt which can sometimes take a hundred years!

What we know

Surface water quickly flows down to the groundwater level, so unconfined aquifers like these are at risk of pollution from surface spills or non-point-sources like intensive agriculture or urban drainage. These aquifers are also closely tied to water levels in adjacent rivers, like the Cowichan River and the Koksilah River.

In the Mill Bay area, recent aquifer studies arranged through CVRD have shown a limited supply of groundwater. There are concerns that the amount of groundwater supply will not be enough to support the community as it grows in this area; however, there are solutions if we plan now.changing_climate_e

In other parts of CVRD, there are subdivisions where water must be trucked in because groundwater is not suitable while other parts have fractured rock aquifers meaning that some of these aquifers can have very limited amounts of groundwater available to wells. In addition, natural contaminants, such as arsenic or boron make well water unappealing for consumption. Sea level rise also can impact groundwater through salt water intrusion into coastal wells.

Many watersheds have water rights for withdrawal that exceed the capacity of the surface water, or related groundwater, to sustain. If all these rights were to be exercised due to increased drought  in the future, the consequences for industry, agriculture, community and ecosystems could be severe.

What we don’t know

The greatest concern in the CVRD is the lack of scientific data about the supply of our groundwater. We don’t know much about our aquifers – the boundaries, depths, as to how aquifers are interlinked, and how much water supply they can sustain. We also don’t know where aquifers are dropping due to overuse, or where they are trending towards increased pollution. Finally, we don’t have data on how much water is being withdrawn – now or in the future.

As a region, we need to organize a concerted effort to obtain better data on existing aquifer conditions, water withdrawals, and trends. With that information, we could foresee where future drinking or agriculture water supply could be an issue and focus management efforts to support sustainable water use and sustainable ecosystems. Monitoring trends can also help provide us with a better understanding of where risks are, if action is urgent and effective. Monitoring may also include climate and precipitation change, lake and ocean levels, stream flows, aquifer levels, groundwater quality, watershed health, and so on.

A worst case is where urban development is allowed without the knowledge of whether water supply for drinking and firefighting is adequate, and after development, it is discovered that water supply is constrained. This leaves the property owners, and through them, the CVRD and its taxpayers, with a very difficult and expensive problem to find and provide alternative water supply.

What can we do? 

To protect our water supply and water quality from potential impacts such as climate change, growth, and land use patterns, the CVRD is already doing the following; however, a region-wide approach is required to develop a clear mandate to support watershed management:

  • Mapping the location and vulnerability of aquifers in our community
  • Launched the Water Balance Model website so that you can explore how your property development/redevelopment plans can help our region better manage our (rain)water resources
  • Built the Coupled Groundwater –Surface Water Model of the Cowichan Valley to understand the contributions of groundwater to the surface water system as well as to understand the rates of aquifer discharge and recharge
  • Developed the Agricultural Water Demand Model to understand the Region’s agricultural water needs
  • Worked with partners to develop pilot agricultural water plans for expanded use across the Region
  • Assessed options and applying for funding for long term storage improvement at Cowichan Lake
  • In February 2016, the province also released new groundwater licensing and fee requirements for non-domestic users.

Planning for the future

As a region, we need to design our communities to protect our surface water and groundwater through good planning, monitoring, and prevention of impacts. The proposed Drinking Water and Watershed Protection Service is a path forward to help facilitate the protection of our water so that we have healthy, sustainable communities for generations.Drinking water and watershed protection service

Specifically, the proposed Drinking Water and Watershed Protection Service will provide the organization and resources to obtain better information on aquifers and groundwater trends in the CVRD. With that information, partners, stakeholders, and community members will be able to avoid problems before they are severe and focus on solutions to problems that are well defined. The Drinking Water and Watershed Protection Service will support better understanding of broad aquifer pollution risks – and will ramp up programs that lead to wellhead protection and septic field maintenance, as well as business-oriented programs to keep pollutants out of sewers.