Ecohydrological impacts on receiving waters induced by stormwater management infrastructure

Session: 43. - Climate Change Impacts on Ecohydrology of Urbanized Watersheds Draining into Large Lakes

Mahyar Shafii, University of Waterloo, Dept. of Earth and Environ. Sci., [email protected]
Philippe Van Cappellen, University of Waterloo, [email protected]

Abstract

Rising global temperatures increases extreme climate and the risk of flooding all across Canada. Conventional StormWater Management (SWM) systems increase hydrological connectivity and loadings of organic matter and nutrients to receiving waters (e.g., the Great Lakes), which results in eutrophication and abundant Harmful Algal Blooms (HABs) in aquatic ecosystems. Green Infrastructure (GI, e.g., bioswales, green roofs), commonly recommended for SWM towards water quantity/quality targets, have shown a range of water retention and nutrient removal efficiencies, with reportedly degrading effects on downstream water quality. Moreover, their catchment-scale evaluations often do not indicate significant benefits. We hypothesize that such performance variations, especially under extreme climates, are due to (i) lack of understanding about nutrient sources within urban areas and biological transformations in GI options, (ii) practical limitations (e.g., maintenance), and (iii) uncertainties in the biogeochemical data/models. The overarching goal in our research is to provide scientific recommendations to researchers and stake-holders for adaptive SWM that minimizes pollution and nutrient export from urban environments. In our presentation, we will highlight the ecohydrological degrading effects of grey and green SWM infrastructure on receiving waters based on our literature review. Our main focus will be on Canadian climates and the Great Lakes basin. 

1. Keyword
climate change

2. Keyword
biogeochemistry

3. Keyword
urban areas

4. Additional Keyword
stormwater management

5. Additional Keyword
green infrastructure