Drinking Water Quality and Supply

From source to sink

Where Duncan water comes from

A plain-language tour of the lakes, rivers, or wells that feed Duncan, the plants that clean the water, and how it reaches kitchen taps. Lab grades for hardness, lead, and pH live on the water quality page.

On the map

Where Duncan water lives

Source waters and treatment plants pinned from published utility names. Open a pin below for the full OpenStreetMap view.

Map showing drinking-water locations for Duncan

Map data © OpenStreetMap contributors. Pins are approximate for orientation, not legal survey points.

Deep dive for households

Duncan drinking water starts as groundwater from wells. The named source on the utility record is Cowichan River sub-river / unconfined aquifer (four deep wells). That is the water that eventually reaches kitchen taps after treatment, not a separate bottled brand.

Water is cleaned at Duncan municipal well system / chlorination before it enters city pipes. Four deep wells and two reservoirs near the Cowichan River; aquifer recharged by river and watershed filtration through pervious soils.

After treatment, water moves through pumps, storage, and underground mains to reach streets and buildings. Distribution covers Duncan and extends into portions of North Cowichan, CVRD Areas D/E, and Cowichan Tribes lands (~15,000 people).

One detail that makes Duncan water feel local: Duncan's aquifer is unconfined and river-connected,summer Cowichan River low flows are a regional water-security concern shared with North Cowichan. Lab grades for hardness, lead, and pH sit on the city water quality page; this overview is about the route the water travels.

Where it starts

Groundwater

Wells and aquifers under the ground.

Research confidence: high

Named source waters

  • Cowichan River sub-river / unconfined aquifer (four deep wells)

Treatment plants

These are the buildings that filter and disinfect water before it enters city pipes.

  • Duncan municipal well system / chlorination

    Four deep wells and two reservoirs near the Cowichan River; aquifer recharged by river and watershed filtration through pervious soils.

How it reaches your street

Distribution covers Duncan and extends into portions of North Cowichan, CVRD Areas D/E, and Cowichan Tribes lands (~15,000 people).

Duncan water quality grades · All city rankings

Source · ECCC / municipal open data (seed). Last updated 2026-07-22. Refreshed on the site's automated schedule.