No regrets

This is an approach referenced in few different studies and seems to fit well with the benefits of LID in light of climate change. Tie back to the fact that climate change projections are uncertain, especially at local scales, so why not implement LIDs – they are practices that work well for stormwater management with and without the effects of climate change.

• Climate change should be considered in future planning but the uncertainty in estimates makes it harder for those involved

• “Acknowledging that there is uncertainty as to how the climate will change and at what rate, the team developed strategies that are built upon three principles which ensure that their recommended actions make sense under any scenario:
  • Triage: Avoiding efforts that are unlikely to succeed and concentrating on areas where improved management can have the biggest impact;
  • Precautionary principle: Not waiting for certainty to act where the consequences of potential impacts are high; and
  • No regrets: Focusing on actions that provide benefits regardless of how the climate changes

• “No-regrets actions are those that provide benefit under both current climate conditions and potential future climate conditions. No-regrets options increase resilience to the potential impacts of climate change while yielding other, more immediate economic, environmental, or social benefits . The no-regrets approach is considered “proactive adaptive management” which is based on the development of a new generation of risk-based design standards that take into account climate uncertainties. There are a wide variety of no- regrets actions that improve the adaptive capacity of the watershed to handle stormwater.”

• ‘No-regrets’ strategies “Faced with uncertainty about future climate change, and given constraints on available resources, communities may choose to pursue no-regrets strategies – actions that are beneficial in addressing current stormwater management needs regardless of whether or how climate may change in the future

“The results of this study also demonstrate the effectiveness of site redevelopment, including increased density and reduced impervious cover as a no-regrets adaptation strategy for reducing pollutant loads associated with stormwater runoff.”

“management infrastructure, a challenge that many practitioners and decision makers are just beginning to consider . Responding to climate change will be complicated by the scale, complexity, and inherent uncertainty of the problem, therefore it is unlikely that this challenge can be solved using any single strategy. The scenario analyses conducted in this study illustrate the potential effectiveness of one common element of LID, reducing impervious cover, in the context of climate adaptation.”

• “Managing green infrastructure for climate adaptation is primarily about managing risks or uncertainties created by anthropogenic activities. The risk-based approach to climate change has three defining aspects: problem framing and role; embedded policy discourse; and planning approaches. First, problems associated with adverse weather conditions, including rainstorms, floods, heat waves and cyclones, tend to be understood in probabilistic terms. The ‘thing’ that matters is not discrete material benefits that can fulfill the needs of the public, but non-linear, irreducible uncertainties associated with changes in the climate. Functioning as a risk buffer, green infrastructure actually helps minimize the impacts of public ‘bads’ (i.e. natural perils) and, by doing this, indirectly provides public ‘goods’. There is limited precision as to where and when these impacts will eventuate and in what manner. The ‘necessity’ for green infrastructure is thus reduced to a matter of probabilities that are influenced by global climatic dynamic and humanity’s collective actions. It is driven by problems that we seek to avoid and are unable to predict with high level of precision.”

---

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Surface runoff from at-grade surfaces, resulting from rain or snowmelt events.

A hard surface area (e.g., road, parking area or rooftop) that prevents or retards the infiltration of water into the soil.

The portion of water precipitated onto a catchment area, which then flows as surface discharge from the catchment area past a specified point.

Water from rain, snow melt, or irrigation that flows over the land surface.

Natural vegetation and vegetative technologies in urban settings such as: urban forests; green roofs; green walls; green spaces; rain gardens; bioswales; community gardens; natural and engineered wetlands and stormwater management ponds; and porous pavement systems. These systems are designed to provide multiple benefits, such as moderate temperatures, clean air and water, and improve aesthetics.

A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Any form of rain or snow.