The Catfish Creek watershed includes Catfish Creek and its tributaries. They drain an area of approximately 490 square kilometres in Elgin and Oxford counties. It enters Lake Erie at Port Bruce.
Much of the land of the Catfish Creek watershed is used for agriculture. The City of St. Thomas and the Town of Aylmer are the major urban areas, with other settlements at Springfield and Port Bruce.
The watershed has one municipal water system in the village of Brownsville in the Township of Southwest Oxford. The water system is owned and operated by the County of Oxford and is comprised of two wells serving about 500 people. A number of communities in the watershed are serviced with municipal water from Lake Erie through the Elgin Area Primary Water Supply, including the Town of Aylmer and Port Bruce and Copenhagen in the Township of Malahide.
The Catfish Creek Source Protection Plan went into effect on Jan. 1, 2015.
The Catfish Creek Conservation Authority is a community-based organization charged with restoring, developing and managing the natural resources of the Catfish Creek watershed.