Mixed Messages from Stormwater Management in the Greater Toronto Area

by Kserviss on November 24, 2016 - 11:37pm

Stormwater management is an indispensible service throughout urban areas due to the high proportion of impervious land cover. Land cover is impervious when water cannot infiltrate into the ground; examples of this are asphalt, cement, and roofs, all common in urban areas. Stormwater management systems direct concentrated runoff during rainfall from impervious land to streams and rivers to avoid flooding. Additional strategies to avoid flooding, such as rooftop gardens and pervious cement, are used at present. These additional strategies are important in protecting urban river systems from extreme peak flows caused by stormwater management systems concentrating runoff into rivers.

The city of Mississauga recently approved taxes intended to charge property owners for municipal stormwater management. The area of the roof on the property determines the amount property owners will pay in taxes. The minimum threshold for the tax is a 287 ft2 roof. Property owners with roofs this size and smaller do not pay anything, as do property owners near Lake Ontario, where runoff is assumed to go directly into the lake. Any larger than that, though, and the cost could be between $50 and $170 per year. The approval of this tax has given rise to some conflict among citizens and the municipality.

This tax is seemingly inequitable between homeowners and owners/operators of businesses and high-rise buildings. The owners/operators are given the alternative to implement additional strategies to reduce runoff and pay up to 50% less, while homeowners are not. The rationale provided by the city for this inequitable tax model is the estimated $525 000 loss in revenue per year should homeowners be offered the alternative. This is an interest conflict as the municipality and its citizens have differing views as to which parties should be able to pay fewer taxes.

The municipality is sending a perplexing message in approving the tax with this inequitable model. It seems as though this tax carries a positive environmental message: implement strategies to reduce rainfall runoff so the stormwater management system is not overwhelmed and rivers systems within the city are disturbed less. The spirit of this message is contradicted, however, by the lack of incentive offered to homeowners to change behaviour.  This results in a behavioural conflict, where homeowners no longer trust the municipality to treat them as equals to owners/operators of businesses and high-rise buildings.

A potential remedy here is to use co-management practices and actively consult potential stakeholders before making decisions. Some homeowners in Mississauga say they have been using runoff-reducing strategies for years, but the municipality seems to have assumed otherwise in the process of conceptualizing this tax. These homeowners feel as though their voices have been left out of the process; they are members of the community and wish to improve it for their benefit and that of their fellow community members. Owners/operators of businesses and high-rise buildings profit from their properties, and a reversal of the incentive system would be a more fair way to implement this tax. If the community came together with its government and local businesses, a fairer tax and cooperative river protection would result.





Hi Kserviss,

First off, great post! The background information you presented was informative and easily understood for someone without much background on the topic. It's admirable that Mississauga is trying to reduce the environmental impacts associated with urban runoff. Taxing homeowners based on roof size seems to be a little biased and favors smaller homeowners. Is this linked to the assumption that smaller homeowners may not have as much of an income to cover the taxes? It also seems to favor families who live in high-rise buildings. How would one even go about dividing the roof of a high-rise building up among everyone who lived within it?

I also am confused as to why high-rise owners and businesses can find alternative options when homeowners can't. Wouldn't homeowners have less runoff in the first place as they are often surrounded by more green spaces than businesses or high-rises? Shouldn't they be the ones who are paying less? Why is the City making money from storm water management? Have they always or is revenue only now occurring after the implementation of the tax? I think it would help your argument to have a bit of background on what the additional revenue will go towards.

This seems to be a strange twist on an economic instrument to control the unwanted behavior of large amounts of runoff apparently directly related to roof size. It’s great that the City is working to implement resource management strategies but these seem to be unequitable. It’ll be interesting to see how this plays out and if other parts of the GTA will take up a similar model.

Overall, very well written and thought out post! Great job! Cheers.