Water Supply on Bowen Island
Q: I heard that developments can deplete the water supply. Is that true?
The Cape is 100% independent from the municipal water supply. It has invested to provide each estate at The Cape with its own, individual subterranean water well. Each well is certified in terms of quality and quantity, and is 300 to 500 feet deep. It has more than enough water and has received reports indicating that it is on a unique, confined aquifer, completely distinct from the rest of the island and therefore not affecting water supply elsewhere. While this is fact, as promoters of sustainable practices, we very highly encourage our residents to build rainwater collection systems. The benefits far outweigh the financial cost. Once residence at the Cape has 5,000 gallons of collection capacity. The owners have discovered that they have not used a single drop of groundwater since they moved in, in 2018. Their rainwater fully supplies their potable and non-potable needs, including the irrigation of their vegetable garden.
Q: Won’t digging wells reduce the amount of water in the soil?
Water on Bowen Island has a good distribution system through its sand and fractured rock, but shallow-dug wells can dry up as the water table falls during the summer. However, the Cape’s wells are 300 to 500 feet deep, falling well below the water table in areas that have an abundance of water.
Q: Does the water supply for the Cape follow Bowen Island Municipality guidelines?
The agreement between The Cape on Bowen Community Development Ltd. and Bowen Island Municipality requires a professional to certify that each lot of the subdivision have a “source of water sufficient to supply 1,100 litres per day of water” and that “a treatment system is commercially available ... to treat the number of litres of water. All water supply wells were dug to these standards to satisfy Bowen Island Municipality’s requirement, with a letter of certification for each individual well.
Small islands have unique physical, demographic and economic characteristics that set them apart geographically. Water issues tend to come up because, living on an island, there is limited access to fresh water. Questions about the water supply on Bowen Island are not uncommon.
Like many other islands, Bowen Island gets it fresh-water supply from rainfall. Over the Pacific Ocean, moist air blows in eastward and falls as rain. This water flows into rivulets, streams and lakes. It’s either carried to the sea or sinks into the ground. Under the ground are slow-moving systems carrying the water through soil and rock. Some are deep, in the form of aquifers; others are shallow and show up on the surface as springs, which, in turn, feed the streams.
Water on Bowen Island is naturally collected in several freshwater lakes, including Killarney Lake and Grafton Lake, which acts as a water reservoir.
Although water on Bowen Island does not flow into underground streams and lakes, which are normally found only in limestone-based geography, it has a good water distribution system through its sand and rock. Any body of rock or sediment that yields useful amounts of water is referred to as an aquifer. The Cape lies on a volcanic bedrock aquifer. Geophysical surveys and test wells dug in 2007 confirmed the presence of water-bearing fractures within the volcanic bedrock, as well as a 10-metre-thick layer of water-bearing sands.
Underground water systems find their way through watersheds to streams, rivers and reservoirs that contribute to the municipal water supply on the island. Concerns may rise that developments using this water supply will limit the amount of overall water available on Bowen Island.
The Cape on Bowen is 100% independent from the municipal water supply. It has invested to provide each estate at the Cape with its own individual subterranean water well. Each well is certified in terms of quality and quantity, and each well’s comprehensive, detailed certification report is available for review by the purchaser. While shallow-dug wells can dry up as the water table falls during the summer, the Cape’s wells are 300 to 500 feet deep.
It has more than enough water, with reports indicating that it is on a unique, confined aquifer, completely distinct from the rest of the island and therefore not affecting water supply elsewhere.
> Water Facts
• The average annual precipitation is approximately 146 centimetres, or 58 inches.
• It is estimated only 15% of rainwater gets stored in natural underground aquifers.
• Using personal reservoirs, such as rooftop catchments, can alleviate pressure on ground reserves.
• Bowen Island is fortunate to be covered with extensive forested terrain. Forests slowly release rainwater to streams, which limits flooding. Slowly released rain also infiltrates the soil better in forested areas than on bare mineral soils. Runoff in bare areas can cause erosion and floods.
• Areas of Bowen Island have shown as much as 70% decrease in water use when meters were installed and residents saw how much they were using. There are a lot of areas to control water usage.