Bonsall Creek is a scenic coastal stream located in the North Cowichan area of Vancouver Island, British Columbia, draining a 36 square kilometre watershed nestled between the larger Chemainus River watershed to the north and the Cowichan River watershed to the south. The creek originates on the slopes of Mount Sicker and Mount Prevost in the west, where elevations exceed 700 metres, and travels approximately 12 kilometres eastward before reaching the ocean near the Town of Crofton. The watershed sits within the Coastal Douglas Fir Biogeoclimatic Zone, one of the rarest and most ecologically distinct zones in British Columbia, covering only about 0.3% of the province. This zone is characterized by Douglas Fir, Western Red Cedar, Western Hemlock, Big Leaf Maple, Red Alder, Pacific Crab Apple, Pacific Dogwood, Garry Oak, and Arbutus — a richly diverse riparian canopy that provides excellent shade and terrestrial insect input to the creek. The surrounding landscape is sparsely developed, with farming and rural residential land uses dominating the valley bottom, while forestry lands — including Municipal Forest Reserve, Crown forests, and private managed forests — cover the upper reaches. Agricultural land is concentrated along the mainstem and tributary corridors, with most farmland used for forage and grass production.