The Kettle Creek watershed is hourglass in shape and drains 520 square kilometers of land in the heart of the Carolinian Zone on the north shore of Lake Erie. Kettle Creek outlets to Lake Erie at Port Stanley at an elevation of 166 metres above sea level. This represents an elevation drop of about 141 metres from its watershed height to the average Lake Erie water level, approximately 1.75 metres per kilometre. This steep drop in elevation results in flash flooding and a high degree of erosion. In many instances the bed of the stream is more than 30 metres below the level of the surrounding land.
The population of the Kettle Creek watershed is approximately 84,000, distributed between an urban core in the City of St Thomas and a rural periphery.
The main branch of Kettle Creek originates at Lake Whittaker, an 11 hectare spring-fed kettle lake. The watershed is comprised of three subwatersheds: Dodd Creek, Upper Kettle Creek, and Lower Kettle Creek.