Access to practical tools & resources to help Canadians better understand and conserve wetlands.


The OWES is a science-based system that is used to evaluate and rank the relative value of wetlands. The ministry's OWES manuals are technical guidance documents that use scientific criteria to quantify wetland values and allow comparisons among wetlands. The manuals provide the evaluation procedures referred to in the Provincial Policy Statement (PPS) and are used to determine wetland significance under Section 2.1 of the PPS. The OWES consists of two manuals: the Southern Ontario Wetland Evaluation System (used to evaluate all wetlands located in Ecoregions 6 and 7) and the Northern Ontario Wetland Evaluation System (used to evaluate all wetlands located in Ecoregions 2, 3, 4, and 5). The wetland evaluation process involves definition, identification and measurement of wetland functions and values. The wetland functions and values recognized in OWES are grouped into four main categories or components: Biological: recognizes that wetlands can differ in terms of productivity and habitat diversity Social: measures some of the direct human uses of wetlands, including economically valuable products (such as wild rice, commercial fish and furbearers), recreational activities and educational uses Hydrological: characterizes water-related values of wetlands, such as the reduction of flood peaks, contributions to groundwater recharge and discharge, and improvements to water quality Special features: addresses the geographic rarity of wetlands, the occurrence of species at risk, ecosystem age, and habitat quality for wildlife, including fish

Additional Information:

Regions: Ontario, Canada

Submitted by: Regina Varrin

Are you sure you want
to delete this bookmark?