The Hamilton Region Source Protection Area encompasses about 447 square kilometres of land at the western end of Lake Ontario. It is a long thin Area, about 52 kilometres in length and typically about 11 kilometres wide. The Source Protection Area stretches from the Township of Puslinch in the northwest to the Town of Grimsby in the east and is primarily within the City of Hamilton. In addition, because it juts up to 11 kilometres into Lake Ontario to the international border, the Area includes approximately 130 square kilometres of Great Lakes water.

Five upper and lower tier municipalities have lands within the Source Protection Area; however, only the City of Hamilton (Hamilton) operates municipal water systems within the Source Protection Area. Portions of municipalities located within the Source Protection Area are supplied water from the Grimsby water system located in the neighbouring Niagara Peninsula Source Protection Area. In total these municipal water systems supply 97 percent of the population within the source protection area with reliable, clean drinking water. The municipal water takings are from two sources – almost 97 percent from Lake Ontario and less than 1 percent from groundwater. Private systems, including wells and cisterns, provide water to the remaining 3 percent of the population.

The Hamilton Region Source Protection Area consists of four relatively large and 15 small watersheds. The headwater areas of three of the large watersheds – Spencer Creek, Red Hill Creek, and Stoney-Battlefield Creeks – form the majority of the surface water divide between this and neighbouring source protection areas. The city core of Hamilton makes up the Urban Hamilton Core watershed where storm sewers are the conduits of water flow. Of the 15 small watersheds, 14 are located in the southern end of the watershed between the Niagara Escarpment and Lake Ontario. The final small watershed is the Urban Hamilton Beach Strip, which lies between Lake Ontario and Hamilton Harbour.

Hamilton Region Source Protection Area Municipalities and Water Supplies

Upper Tier MunicipalityLower Tier MunicipalityArea Within Hamilton Source Protection Area [km2]Population in Source Protection Area1Percentage of Population in Source Protection Area on Municipal Water Supply2
County of WellingtonTownship of Puslinch194380
Regional Municipality of NiagaraTown of Grimsby1.440717
City of Hamilton425455,93197


  1. Populations are based on Statistics Canada Population Census 2011.
  2. The municipal water system supplying a portion of the City of Hamilton is not located within the Source Protection Area.