Reimagining the Avon River for recreation and nature
OPINION: There is no doubt that a large water body in the red zone could address many unmet needs for recreation in the east of Christchurch.
And exploring synergies and ways to integrate some of the many ideas proposed for the Avon River red zone – the Otakaro Avon River Corridor – are core objectives of Avon-Otakaro Network.
We have recently developed a concept around recreational renaturalisation of the river with a particular focus on Kerrs Reach that allows for flatwater sports and a river floodplain too.
For some time East Lake Trust has proposed a large groundwater sourced lake for flatwater sports and other recreational activities. The proposal would create a lake over 2 kilometres long and up to several hundred metres wide running through the red zone between Dallington and Horseshoe Lake roughly parallel to Kerrs Reach, land that could otherwise be re-naturalised as floodplain for the river.
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Many of us supported an off-river lake because of the poor water quality in the river – it still receives sewage overflows in high rainfall events after all. Secondary contact sports can operate in this environment albeit with considerable care, but it is not suitable for primary contact. In short, it is not a swimmable river.
But things have changed in the past five years. The public is now demanding significant improvements in river water quality; central government has introduced national standards; and the Christchurch City Council has sought a postponement to its application for consent to continue to discharge into the rivers and is under pressure to up its game.
If we want to reach aspirational river quality standards, do we achieve this by moving vulnerable activities off-river or aspire to increase them on-river?
That question is very timely in connection with the red zone where there's vast potential for re-imagining a large part of Christchurch to meet recently announced regeneration objectives. The recreational potential of the river is part of the equation and there are many ways it could be applied.
It could for example accommodate an in-river flatwater course based around a reconfigured and renaturalised Kerrs Reach that runs from Avon Park up to the west side of Avondale Bridge. This stretch could be made long enough and wide enough to meet competition standards for all flatwater codes.
There could be tremendous advantages to such an approach. It is likely to be considerably cheaper than an off-river lake for starters.
There are also new advances in technologies for attractive river bank designs for flatwater sports lakes that use native plants, deter exotic geese and ducks, and dampen reflected wash from water craft that prevent the need for wide shallow-angled banks.
It also means that a lot of the Dallington red zone, and particularly Horseshoe Lake red zone, could be re-naturalised as river floodplain. Some initial modelling has been done that demonstrates the plausibility of this in terms of hydrology and resilience to sea level rise. Opportunities for enhancing mahinga kai values including improving habitat for inanga (whitebait) are also greatly increased.
Imagine a lattice work of small waterways and wetland bush that connect to the river via bridged gaps in the inner stopbanks, but with enormous capacity to absorb flood waters. Consider exploring that in a kayak, or by bike or foot via a myriad of pathways and waterways, and there's likely to be considerable tourism potential.
There is also scope for fresh water swimming and other water attractions as part of the Wai Huka o Waitaha whitewater and surf park proposal. These proposals are looking to use small volumes of ground water (from an aquifer separate from those supplying our drinking water) which would then feed into and help refresh the river.
Some might argue that widening the river is significantly re-engineering its course and flow. On the other hand this is already a highly engineered part of the river.
The re-engineering of the stopbanks and course of the river is likely to be needed for flood management anyway and there is a real opportunity to re-naturalise the river in a way that produces the most benefit for the most people while also respecting its nature.
And New Brighton Road could continue along its current path without obstruction.
How much of this is feasible? We simply don't know without more work, but recreational re-naturalisation of this type is surely worth seriously considering if it means we can have our cake and eat it too.
Evan Smith is the co-chair of the Avon-Otakaro Network.