 It is one of the world's relatively few tidal lakes, and among the largest.In Pitt Lake, there is on average a three foot tide range; thus Pitt Lake is separated from sea level and tidal waters during most hours of each day during the 15 foot tide cycle of the Pitt River and Strait of Georgia estuary immediately downstream.The lake's southern tip is 20 km upstream from The Pitt River confluence with the Fraser River and is 40 km east of Downtown Vancouver.