Module 5: Guidelines, Targets and Incentives

This module explores further how guidelines, targets and incentives are used by municipalities to regulate and stimulate the implementation of green infrastructure. Guidelines and targets are used to communicate the desired outcomes of GI systems and the acceptable means of reaching them. Incentives include: stormwater fee discounts; development incentives; rebates and financing; and awards and recognition.

The guidelines and targets adopted by a municipality often represent a balance between the goals of a municipality and their will, capacity and resources to meet those goals and they can vary greatly between municipalities. Contextual factors such as climatic conditions, local ecological resources and the purpose of the system being designed also have important considerations. As well, guidelines and targets are dependent on institutional factors such as the level of commitment of the governing bodies that set these regulations and the capacity of their workforces to carry them out.

Targets and guidelines represent two distinct regulatory tactics common to most engineering disciplines. Targets refer to quantitative or qualitative performance goals of individual GI systems that are designed to help address whatever factors motivate a municipalities grey-to-green transition. Targets are prescriptive in the sense that a designer will have to demonstrate using established monitoring data or best practices that a proposed GI system will provide the level of service that the target requires. However targets can also be flexible means of regulation that allow designers the freedom to create systems as they see fit, as long as they meet the performance target. Guidelines refer to the approved best practices for designing GI systems in a particular municipality. Guidelines can represent a flexible form of regulation that can be superseded when context or innovation require. Many municipalities will accept designs that are not in line with their adopted engineering guidelines if the proponent can demonstrate the system is safe and effective, however the approval process for designs that fall outside approved guidelines is often prohibitively long and expensive. When municipalities go to the effort of reviewing and adopting an engineering design guideline for a specific system, it can make them less inclined to approve systems that vary from that guidance.

In Ontario, the Conservation Authorities offer guidelines to developers and municipalities on green infrastructure best practices for design, installation, and maintenance. These guidelines are outlined in the STEP Low Impact Development Stormwater Management Planning and Design Guide included in the Additional Resources section. While the Conservation Authorities have development approval authority for development applications near waterways, the guidelines they produce are only suggestions on how to receive their approval within theses areas. Municipalities within the Conservation Authorities watershed are under no obligation to adopt these recommendations as their own binding standards for development proposals. In contrast, New York City has adopted a broad and comprehensive set of standards for GI implementation that apply everywhere within city limits. These standards are outlined in their 2020 document, Standard Designs and Guidelines for Green Infrastructure Practice included in the Additional Resources section.

In November 2019 the City of Vancouver set a target for new developments to capture and clean 48mm of rainfall over 24 hours. In contrast, Toronto municipalities are facing difficulties in implementing a capture target of less than 29mm. Upon adopting the 48mm target, the City of Vancouver had few approved GI standards in place which would allow engineers and developers to meet it. The target is intentionally aspirational and relatively open-ended. It has been adopted to spur GI implementation and accelerate the adoption of the regulations and standards required to ensure the efficacy of these systems. The City intends to create a set of adaptable regulatory guidelines that are better suited to accommodating the relatively rapid rate of change in GI best practices and technologies. City of Vancouver will also require new developments to control post-development flows to pre-development flows based on a post-development IDF curve for the year 2100 to account for additional rainfall due to climate change. If these new standards are successfully implemented, the City of Vancouver will be a global leader in sustainable rainwater management and an example to other municipalities pursuing grey-to-green infrastructure transitions.