The Tuplin Creek watershed is situated in the central third of Margate and the eastern eighth of Kensington district. The highest elevations of 54 to 58 m are found at the south end of the area. The land generally slopes northeastward to the Southwest River estuary.
Tuplin Creek begins east of Kensington and flows about 5.0 km in a northeasterly direction. Along the way it is twice crossed by Rte 6 before it reaches Margate where it is crossed a third time before it enters an 0.9 km long estuary on the south side of the Southwest River. North of Margate, it is paralleled by the Thompson Point Rd. Several tributaries totalling 2.1 km drain into the creek over its length.