09/05/2025
The vision of restoring native habitats along the Ōtākaro Avon River Corridor (OARC) is commendable and widely supported. However, portraying the multi-million-dollar asphalt City to Sea Pathway as a "model of sustainability" is misleading and overlooks critical environmental and safety concerns.
Advocates claim the pathway exemplifies climate adaptation, yet its construction on land well below the Avon River's floodplain in South Richmond contradicts this assertion and ignores the fact changing weather patterns and sea level rise - both of which are brought on by climate change - are going to have an increasingly frequent impact on Christchurch and the Avon River.
The recent heavy rainfall event earlier this month led to the river overflowing its banks, not only shutting both northbound lanes and a southbound lane on Fitzgerald Avenue (where the Avon routinely floods the road), but also completely submerging significant sections of the City to Sea Pathway under nearly knee-deep floodwaters, rendering what is being described as a 'transport corridor' completely impassable. This outcome is not indicative of adaptive design but rather a predictable consequence of placing impermeable infrastructure within a known flood zone. Let's not ignore the fact the Christchurch City Council were advising people to stay well clear of flood waters due to the dangers they pose.
The City to Sea Pathway traverses land identified by the Council commissioned Liquefaction Vulnerability Maps as being of the highest susceptibility to liquefaction, lateral spread, and severe ground deformation during seismic events, all of which are detrimental to infrastructure. This same land was red-zoned post-earthquakes for being too unstable to rebuild upon—a fact seemingly overlooked in defenses of the City to Sea Pathway project by its advocates.
Contrary to what Hayley Guglietta, Spokesperson for Otakaro Avon River Corridor, wrote, asphalt surfaces do not absorb water; instead, they accelerate stormwater runoff, increasing both the speed and volume of water flow, which can exacerbate flooding. This contrasts sharply with natural flood management strategies that utilize features like wetlands, forests, and trees to absorb and slow down floodwaters.
Moreover, the construction of the pathway involved hours and hours of diesel-fueled heavy machinery, pumping greenhouse gas emissions into the atmosphere.
If sustainability and environmental foresight were truly at the forefront, the project would have prioritized reforestation and the enhancement of natural flood defenses over the installation of an asphalt pathway. Vegetation, particularly trees and shrubs, plays a crucial role in mitigating flood risks by absorbing rainwater, enhancing soil infiltration, and slowing floodwaters.
Investing in infrastructure on land known for its high liquefaction and flooding risks raises serious questions about the project's long-term viability and alignment with sustainable practices. True sustainability involves working with natural systems to create resilient and adaptive urban environments.
Redirecting funds towards reforestation of the riverbanks and surrounding land within the floodplain and the development of stormwater retention basins would offer more enduring benefits, both environmentally and fiscally, than a pathway likely to require costly repairs or replacement in the future.
The Council's decision to proceed with this pathway reflects a disregard for established environmental risks and a misrepresentation of sustainable practices. It's imperative to critically reevaluate such projects to ensure they genuinely align with principles of ecological resilience and fiscal responsibility.
