Resilient infrastructure : a key priority for a sustainable future
The resilient and sustainable design of stormwater management infrastructure has become an urgent priority in a world shaped by climate change and rapid urbanization, presenting unprecedented challenges for our urban infrastructure systems.
These factors increase pressure on existing infrastructure, which is not suited to new climate realities. The Greater Montreal region serves as an example where numerous initiatives have been launched to adapt infrastructure, particularly in stormwater management, to address environmental challenges.
This article explores strategies and solutions aimed at ensuring infrastructure resilience while promoting sustainable development. This project aligns with a sustainable vision, providing adaptability to future hydrological changes.
The implementation of these advanced concepts and techniques represents significant progress in municipal engineering practices and technology, offering a new perspective on the capacity of urban communities to adapt to changing hydrological conditions. Achieving this goal aims to drive concrete actions toward creating more sustainable and resilient infrastructure, capable of protecting our urban ecosystems and promoting the well-being of the communities involved.
Why invest in green infrastructure ?
Municipalities and businesses must prepare for extreme weather events such as severe storms and floods, which are becoming increasingly frequent due to climate change. The integration of resilient infrastructure helps protect citizens and ecosystems from the impacts of climatic hazards. It significantly contributes to public health and biodiversity preservation.
Green infrastructure, such as green roofs and bio-retention systems, helps reduce stormwater runoff, thereby minimizing the risk of flooding in urban areas.
Impacts of urban development on stormwater management
Urbanization significantly alters infiltration volumes, flood flows, and stormwater runoff quantities. To mitigate these consequences, it is imperative to adopt stormwater management methods focused on reducing runoff volumes. These approaches should be implemented proactively from the early stages of urban development.
Ecological vulnerability related to flooding
When water runs off impermeable surfaces, it carries pollutants into sewer systems and watercourses. In the event of heavy rainfall, sewage systems can become overloaded, leading to back-ups, surface flooding, and the discharge of partially or untreated wastewater into the natural environment. This can lead to a deterioration in water quality and limit recreational activities on contaminated waters.
Catastrophic Insured Losses in Canada (1980-2017) (IBC Wetlands report 2018 final)
Economic consequences of flooding
The increase in runoff and stormwater pollution presents major economic and environmental challenges for municipalities. In Canada, the costs associated with flood damages and climate change are rising, reaching $1.8 billion between 2009 and 2017. Municipalities must address these challenges by identifying and mitigating high-risk areas in their urban planning, in accordance with the Planning and Urbanism Act. Flooding, primarily caused by intense rainfall, represents the most common climate risk for municipalities, which own 60% of the country’s public infrastructure.
To protect citizens, it is crucial to adopt resilient solutions, including the integration of green infrastructure to promote water infiltration into the soil. Sustainable stormwater management must be at the heart of urban planning practices to minimize runoff into watercourses.
Anticipating climate change in urban drainage
Global climate change, confirmed by the IPCC report of 2007, indicates a probable increase in the intensity of future storms, which will have a significant impact on the creation of drainage systems and the preservation of associated service levels, constituting an essential aspect of drainage network planning. Urbanization impacts precipitation and runoff. According to the IPCC report, by 2040, precipitation could increase by 4 to 21%, particularly during extreme weather events such as storms. This phenomenon poses a major challenge for existing infrastructure. These recommendations must be adapted considering long-duration precipitation and winter thaw events, which may become more frequent due to climate change.
Building flood resilient communities
To build communities capable of effectively resisting flooding, it is essential to adopt a comprehensive approach that encompasses four fundamental principles:
Resilience: ensuring the protection of infrastructure and the environment.
Reliability: guaranteeing the functionality of infrastructure under various scenarios.
Redundancy: providing backup capabilities and network flexibility to maintain services.
Effective response and recovery strategy: allowing for proactive flood management and rapid post-incident recovery, which are crucial for the development of residential areas adapted to the challenges posed by flooding.
Resilience is perceived as a dynamic property that describes the ongoing capacity of an element or system to face threats, in contrast to the risk approach, which focuses more statically on the precise moment when a failure occurs. According to research by Ayyub (2012) and Linkov et al. (2014), although these two perspectives differ, resilience is not intended to supplant traditional risk assessment. Instead, it should be viewed as a complementary tool to risk analysis, particularly in the context of infrastructure systems.
Design strategies for resilience
When designing new residential neighborhoods in natural areas, it is essential to preserve ecological functions and manage flood risks by maintaining floodplains and buffer zones intact, avoiding an increase in flood risk within the watershed, and restricting developments in areas at risk of debris flows, ice, or high groundwater levels.
Projects must integrate mitigation measures such as adequate drainage systems and structures designed for an effective stormwater network, while ensuring that runoff is managed to avoid negatively impacting the environment or existing infrastructure, in accordance with local guidelines.
According to the brief submitted during public consultations on the modernization of the regulatory framework in water environments, including floodplains and the management of flood protection works, regulatory modification suggestions have been presented based on exposure risks. For areas with very high risk, it is proposed to establish sectoral management plans, improve the compensation regime, and allow for the relocation of affected property owners, while reassessing standards to promote more resilient reconstruction. Moderate-risk areas would receive similar proposals, with a revision of standards to enhance resilience. In contrast, for low-risk areas, the current proposal is deemed sufficient and does not require significant changes.
LIVING IN THE CITY (2019). Planning for the climate: integrating the reduction of greenhouse gas emissions from transport into land use and urban planning , 64 p. (coll. Towards viable communities ).
Types of resilience
There are two main categories of resilience:
Technical Resilience: This focuses on a system's ability to maintain or quickly regain a stable operational state with little or no variation, essentially preserving operational efficiency after an incident.
Ecological Resilience: This is defined by a system's capacity to adapt and survive in various states, emphasizing the preservation of overall integrity rather than the maintenance of a specific function. A system that is highly resilient from a technical perspective may exhibit low ecological resilience, and vice versa. Studies suggest that, particularly in the context of flood risk management, ecological resilience offers a potentially more advantageous approach for long-term sustainability and the adaptive capacity of systems.
Innovative strategies for sustainable and resilient stormwater management
The urgent need to rethink traditional stormwater management methods in favor of more integrated and sustainable approaches, such as Sustainable Stormwater Management (SSM), is crucial. These approaches, which combine nature-based solutions and green infrastructure, aim not only to mitigate the effects of urban runoff but also to restore the natural hydrological cycle while positively contributing to biodiversity and enhancing quality of life in urban areas.
Emphasis is placed on the necessity for resilient planning that can adapt to and withstand extreme weather conditions, reinforced by digital modeling to anticipate the future impacts of climate change on urban drainage systems. The advocated approach is proactive, highlighting the importance of innovation and interdisciplinary collaboration in designing infrastructure that effectively manages stormwater and promotes the development of sustainable urban communities.
Advanced engineering approaches and solutions
At FORCE, our infrastructure projects implement techniques and strategies that maximize efficiency and resilience in the face of these hydrological challenges.
1. Bio-retention Systems and Rain Gardens
Bio-retention systems and rain gardens are green infrastructures designed to capture and infiltrate stormwater. These systems treat water at the source by filtering pollutants through layers of soil and plants, which reduces runoff volumes and improves water quality. Two types of configurations exist:
Systems with complete infiltration, where water completely infiltrates the soil, reducing runoff volumes by 100%.
Systems with partial infiltration or underground drainage, where water is partially filtered before being drained.
2. Infiltration Trenches
Infiltration trenches allow for the collection of stormwater to be infiltrated into the soil. This device is recommended in areas where soil permeability allows for rapid infiltration. This significantly reduces the volume of water discharged into sewers while recharging groundwater.
3. Green Roofs
Green roofs are an effective solution for managing stormwater in urban areas. They absorb precipitation, promote evapotranspiration, and reduce runoff. In addition to managing stormwater, they provide benefits in terms of thermal insulation and biodiversity enhancement.
4. Permeable Pavement
Permeable surfaces, such as pavers, allow rainwater to infiltrate directly into the soil, helping to decrease runoff volumes in urban areas. This technique is used on parking lots, driveways, or sidewalks and can reduce rainwater runoff by up to 100%.
5. Retention Basins
Retention basins are infrastructures designed to temporarily store stormwater before slowly releasing it into drainage systems. They can be dry or permanent, depending on project needs. These systems help manage peak runoff, thereby reducing flood risks.
6. Grass Swales
Grass swales are vegetated ditches that capture, treat, and infiltrate stormwater. They are often used along roads and in green spaces to manage runoff at the source while improving water quality.
7. Underground Storage Systems
These systems, such as rainwater cisterns or underground reservoirs, allow for the storage of stormwater for later reuse (e.g., for irrigation) or for gradual release into drainage networks. They help reduce peak flows and manage water volumes during rain events.
8. Filter Strips
Filter strips are vegetated areas that capture and filter runoff water before it reaches sewers or watercourses. These areas help reduce pollutants, such as suspended solids and nutrients, present in the water.
Integrating technology into urban planning
Resilient infrastructure design is not limited to isolated technical solutions. It involves integrated urban planning where each element is optimized to work in synergy with the natural environment and the specific needs of communities. At FORCE, we adopt a holistic approach by integrating stormwater management systems into urban master plans. This includes preserving local ecosystems, protecting floodplains, and adapting infrastructure to future climate conditions.
Our experts work closely with municipalities, real estate developers, and public sector stakeholders to propose solutions that meet regulatory requirements while being economically viable.
Why should businesses and communities invest in resilience?
Investing in resilient and green infrastructure is essential to minimize the high costs associated with repairs and natural disasters, particularly flooding. The resilience of infrastructure ensures the safety and sustainability of communities. At FORCE, we offer innovative solutions to address these challenges by constructing infrastructure capable of withstanding extreme weather events while thriving. The goal is to prepare for a safe and sustainable future by utilizing appropriate technologies and strategic planning that promote urban sustainability and community safety.
Comments