Wetlands provide many…

Wetlands provide many critical economic, social, and environmental services (Whiteley and Irwin 1986, Zedler and Kercher 2005, Yang et al. 2016). Wetlands improve water quality via water filtration and reduce financial and social costs to homeowners and the government by flood prevention and securing groundwater for human use. A recent study estimated that the wetlands in the Credit River watershed reduce insurable claims for a single flood event by 46% and reduce property damages 17 to 29% (up to $3.5M, the wetlands in the Laurel Creek watershed reduces insurable claims for a single flood event by 18% and reduce property damages 38 to 51% (up to $53M) (Moudrak et al. 2017). Wetlands have never been more important with climate change increasing the frequency of severe weather precipitation events.

I support updating the Ontario Wetland Evaluation System (OWES) for conciseness and clarity but have concerns around the proposed updates. My primary concern is that the proposed changes will threaten economic, social, and environmental services provided by wetlands by (1) degrading wetland function through the fragmentation of wetland complexes, and (2) preventing municipalities from identifying wetlands that protect public and private infrastructure.

#1 Wetland complexes are – by definition – linked to one another through hydrological and hydrogeological processes. Failing to identify the broader complex threatens the long-term function of the complex with consequences for ground water recharge, flood management, and property loss. It is important to keep wetland complexes within the OWES by explaining what they are (pages 9 and 26 in the Proposed Updates) and ensuring that the wetland complex is evaluated in its entirety to prevent fragmentation (pages 7-8 in the Proposed Updates). In short, wetland complexes must be maintained within the OWES.

#2 Locally Important Wetlands: Wetlands provide a critical service to Ontarians by protecting public and private. Removing municipalities’ ability to protect locally important wetlands (page 63) increases the risk of losing functionally important wetlands that may not meet the 600-point threshold to be designated ‘provincially significant.’ Municipalities must be given the latitude to protect wetlands that protect public and private infrastructure from floods, provide groundwater to nearby residents, or impact other important community needs.

#3 Wetlands under 2 ha should added to the OWES. Recent research details wetland conversion in 7 Ontario municipalities and found that most lost wetlands were less than 2 ha in size and that stormwater management ponds intended on mitigating risk were smaller than lost wetlands (Birch 2019, Birch et al. 2022). Small wetlands provide ecosystems services that are not directly replicable by stormwater management ponds (Rooney et al. 2015) and must be considered within policy.

Resources:

Birch. 2019. An Examination of Wetland Conversion and Resulting Effects on Landscape Connectivity in Southern Ontario Municipalities. MES thesis. University of Waterloo.

Birch et al. 2022 Trends and predictors of wetland conversion in urbanizing environments. Journal of Environmental Management 310: 114723.

Marchildon et al. 2016. A methodology for identifying ecologically significant groundwater recharge areas. Canadian Water Resources Journal 41:515-27.

Moudrak et al. 2017. When the big storms hit: the role of wetlands to limit urban and rural flood damage. Prepared for the Ontario Ministry of Natural Resources and Forestry. intact Centre on Climate Adaptation, University of Waterloo. https://www.taywatershed.ca/documents/When-the-Big-Storms-Hit.pdf

Yang et al. 2016. Examining water quality effects of riparian wetland loss and restoration scenarios in a southern Ontario watershed. Journal of Environmental Management 174: 26-34.

Rooney et al. 2015. Replacing natural wetlands with stormwater management facilities: Biophysical and perceived social values. Water Research 73: 17-28.

Whiteley and Irwin. 1986. The hydrological response of wetlands in southern Ontario. Canadian Water Resources Journal 11: 100-110.

Zedler and Kercher. 2005. Wetland resources: status, trends, ecosystem services, and restorability. Annual Review of Environment and Resources 30: 39-74.