Why harvest rainwater?
When people think of the BC coast, they think of rain. Damp, grey, wet days. So when I moved here it surprised me that there was so much concern about water supply and fears of shortages. How could a place with so much rain be worried about running out of water?
So I started researching water resources here on Vancouver Island, particularly community water systems and groundwater resources to find out what was up. With university training in engineering and earth sciences, and over 15 years of work experience understanding industrial impacts on groundwater I felt pretty well-equipped to understand the reality of the local water challenges.
What I learned was that unlike other areas in the country, BC gets most of its water outside of its growing season. Our dry summers lead to a big strain on freshwater resources as residents and businesses irrigate their lawns and gardens, and vacationers flock to BC's beautiful places on their summer holidays.
We lose most of our rainfall to runoff, and it ultimately gets lost to the ocean. Roughly 20% of rainfall on small coastal islands gets retained to replenish freshwater resources and the rest is lost to the sea.
We can capture this abundant freshwater resource (rainwater) when we have so much in fall and winter and store it for the drier months through spring and summer. By doing so, we can reduce our impact on local freshwater resources including streams, lakes, aquifers, and community water systems.
A carefully designed rainwater harvesting system provides a safe, sustainable water supply for any purpose, even household drinking water.