The amount of time it takes water to pass through a lake, or the pace at which water in the lake is replaced, is one of many factors that can affect the quality of water in a lake.
A shorter retention time (or higher flushing rate) means that water moves from the lake’s inflows to its outflows at a quicker pace. The replacement speed depends on many things, including the size of a lake and amount of precipitation.
For local context, a report produced by the BC Lake Stewardship Society indicates that Prospect Lake had a retention time of 0.8 years in 2012.
The estimate for Elk/Beaver Lake is 5-9 years depending on how it is calculated.
Learn much more in the full Lakes of Victoria, BC guidebook!

In the full guidebook, discover where to:
- Walk: enjoy lakeside strolls & boardwalks.
- Hike: discover single-track trails & scenic views.
- Swim: find the best beaches to soak up the sun.
- Fish: learn about stocking trends and piers.
- Paddle: explore shorelines, and hidden bays.
- Bike: plan your next route and hit the trails.
Along the way you will meet the animals and plants that call these lakes and watersheds home, unearth forgotten place names, and learn stories of days past.
The book is full of useful maps, access information, and local trivia to get you started on your next family day or great adventure.
From locals to visitors, everyone will learn something new about the freshwater lakes that bring Victoria to life.