erty owner’s annual tax bill. The advantage of a levy is a dedicated revenue stream for the stormwater program, but the potential for inequity is not solved. A disadvantage for all tax-based systems is that taxes must be raised to increase stormwater funding. A stormwater rate can be a solution to many of the issues with tax-based funding. A rate allocates charges to individual properties and is administered as a user fee. In the same way water rates can be based on volume of water consumption, stormwater rates can be based on the volume of stormwater runoff. It is impossible to directly measure the volume of runoff from each property and so an indicator is used. The area of impervious ground cover (e.g., rooftops, driveways, and parking lots) is a common indicator of stormwater flow and pollution discharge potential. Figure 2 illustrates the impervious area for a non-residential property, highlighting the building footprint in the left panel and the driveway and parking areas in the right panel. The sum total of these areas within the lot boundary represents the total impervious area for this property. Stormwater rates range in complexity from flat rates to variable rates based on direct impervious area measurement. The flat rate offers the least user-pay equity, but is easy to implement and administer. A variable rate is more equitable, but is more costly to set up and administer. Stormwater rates are calculated based on billing units. The basic calculation for a stormwater rate is simply the municipal stormwater program expense divided by the number of billing units within the municipality. For example, a single family unit stormwater rate structure uses the impervious area of the average single-family detached home as the billing unit. One stormwater billing unit is applied to all single-family homes. Multi-family dwelling units are smaller than single-family homes so a factor is used to reduce the billing unit for these property types. The billing units for non-residential properties are determined by measuring the impervious area of each property. There are 20 to 30 municipalities across Canada that have either implemented, or are in the process of implewww.esemag.com
menting, a stormwater rate. All municipalities are different and it is important to complete a thorough review in order to develop an equitable user-pay funding solution. Usually taxation does not provide equitable funding. However, Vernon is a special case. Figure 3 shows that in many Canadian communities, impervious area is not tied to tax contributions. In Vernon, the two are closely related. This means that funding stormwater through taxation presents a fair and equitable solution for Vernon.
PUBLIC AWARENESS The general public is unaware of the devastating effect rainwater can have on our infrastructure and there is a lack of knowledge regarding stormwater. It must be communicated to residents that stormwater management is critical and that this is more than a “rain tax”. CONCLUSION Vernon’s funding for stormwater was
not sufficient to meet either the minimum or the sustainable level of service. The community’s desire is to receive a functional drainage system and improve environmental health. As a result of the funding study and previous initiatives, the City is taking steps to ensure sustainable funding for stormwater management. The correlation of impervious area to land use type concluded that taxation is an equitable solution. While a stormwater rate offers many benefits, in this instance it made more sense to continue with the well-established taxed based funding system. The 1.9% cumulative levy will eventually provide sustainable funding for infrastructure renewal. There is potential to extend the levy and repurpose it to stormwater operations and maintenance funding. Jason Foster, P.Eng., is with AECOM Canada. For more information, email: jason.foster@aecom.com
PREVENT OVERFLOWS Lowest Cost Sewer Level Monitoring System • • • •
Detect blockages early Eliminate customer complaints 10 minute surface installation Intrinsically safe
www.adsenv.com/echo
WHEN OVERFLOWS MATTER - ADS MONITORS
October 2016 | 39