The City of Mississauga is set to implement a stormwater charge which will be integrated into the Region of Peel water bill. AutoCase for stormwater now has Canadian data and so I use AutoCASE to run a cost benefit analysis for an example Mississauga green infrastructure project to see how Mississauga, the environment and society will benefit. The benefit from a non-residential property owner converting 1 acre of parking lot to porous asphalt and installing a 100 gallon cistern has a median Sustainable Net Present Value (S-NPV) of $1,123.
Beginning in 2016, the fee will be assessed to provide much needed improvements to the estimated $1.8 billion of stormwater infrastructure maintained by the city of Mississauga.
Residential property owners will be assessed a fee ranging from $50 to $170 depending on the amount of impervious surface on their property. 80 percent of homes will fall in the smallest to medium category resulting in stormwater fees of $50 to $100. A medium sized, detached home previously paying $25 for stormwater infrastructure through property tax will see that cost increase to $100.
Non-residential property owners will be assessed a fee of $94 per 2,872 sq. ft. of impervious surface. Non-residential property owners previously paying $10,445 for stormwater infrastructure through property tax will now be paying $49,000. A credit system will also be made available to non-residential property owners wherein they will be able to reduce the charge up to 50%. The credit will be applied to properties that reduce their water runoff, which can be done through a variety of green infrastructure options. The city of Mississauga highlights rainwater harvesting, bioretention facilities, and soakaway pits as options for improving commercial property drainage. The credit offers incentives to construct other low impact development features such as permeable pavement, bioswales, and green roofs which offer a host of economic, sustainable, and environmental benefits.
AutoCase for stormwater now has Canadian data which can be used to run a cost benefit analysis for a Mississauga green infrastructure project. The benefit for a non-residential property owner to convert 1 acre of parking lot to porous asphalt and install a 100 gallon cistern has a median Sustainable Net Present Value (S-NPV) of $1,123. This S-NPV does not include the potential stormwater credit which means the owner can create $1,123 of value on top of the stormwater fee reduction. Increased property value, flood risk mitigated, and avoided operations and maintenance costs are the largest benefits for this project.
The annual stormwater project costs in 2012 were estimated to be $27.6 million which included flood mitigation, erosion controls, and a future pipe replacement fund. As the stormwater infrastructure ages these costs will continue to rise. The current stormwater system has an estimated replacement cost of $1.8 billion and it is nearing the end of its lifecycle. The stormwater charge is expected to generate $40 million which will be used for operating costs, technical exemptions and credits, pipe renewal reserve fund, and capital improvements. Repairing and rehabilitating stormwater infrastructure generates significant benefit due to the avoided cost of infrastructure failure. Establishing a direct revenue stream for stormwater infrastructure will provide the city of Mississauga the means to keep up with rising costs as well as growing their pipe replacement fund to invest in repair or replacement projects.