Tetrahedron Provincial Park and Chapman Lake are under threat - The Forthcoming Amendment to Tetrahedron Provincial Park
The Sunshine Coast in 2015 and 2017 experienced Stage 4 drought in the Chapman system, the highest severity level of drought which bans all outdoor tap water use. The Chapman system provides water to 85% of the Sunshine Coast water users and the system refers to the watershed containing Chapman Lake and Creek. The lake and upper reaches of the creek are inside Tetrahedron Provincial Park.
The current surface area of Chapman Lake is given as 345,518 m2 at lake full. At 8 meter drawdown, the area is reduced to be 194,445 m2. That is 56% of lake full surface area. The northeast stream is classified as high quality fish habitat suitable for all stages of fish life cycles (spawning, rearing, overwintering, migration, and spawning/holding). It contains 240 meters of good habitat that is critical in sustaining fish. During drawdown the northeast stream would flow onto dry lake bed leaving fish exposed without a channel, cover or streamside vegetation. The drying mud flats would extend 137 meters from the outflow to the lake at 8 meter drawdown. It is unlikely any fish would survive the transit and access to Dolly Varden spawning areas would not be possible.
The SCRD timetable has Chapman Lake removed from the park by a boundary amendment in fall of 2018 and construction in summer of 2019. The construction plan is to install an almost 1 meter diameter pipe at 9 meters below the lake full water level with the ability to drawdown the lake by 8 meters.