According to https://ltsa.ca/docs/Land-Districts-of-British-Columbia.pdf, the land area enclosed within relation #11524856 falls within Bright Land District. However, this disagrees with LTSA’s own “ParcelMap BC” service, which depicts this area to be part of Cowichan Lake Land District. This is a discrepancy of about 52.5 km². As a legal document officially declaring this area to be within Cowichan Lake Land District has not been found, I have instead had to use the descriptions given in the linked PDF to draw the boundary between these two land districts, and so OpenStreetMap now depicts this area to be part of Bright Land District.