Attempt to keep rowing lake afloat
The trust behind a world-class rowing lake idea for Christchurch’s residential red zone will seek high-level intervention to keep the project afloat.
Regenerate Christchurch has rejected a watersports lake in its draft shortlist of options for the land, citing its effect on the environment.
The agency instead says the Avon River area from Kerr’s Reach to the estuary should be upgraded to its pre-quake condition or widened.
The East Lake Trust, which promoted an out-of-river lake from Kerr’s Reach to Horseshoe Lake, says Regenerate’s conclusion is based on ‘‘inaccurate’’ information. Chairman David Goodman says he will write to Regenerate chairwoman Sue Sheldon and Greater Christchurch Regeneration Minister Megan Woods asking for the decision to be reconsidered.
Regenerate Christchurch chief executive Ivan Iafeta said yesterday two documents provided by East Lake Trust itself showed 500 litres per second – or 43.2 million litres per day –would be extracted from deep water aquifers to keep the 2.2-km lake free of algal blooms.
Iafeta said 43 million litres was about one-third of the average amount of drinking water the city used daily.
‘‘This supports our decision to take a long-term view of what’s best for the city and prioritise our natural environment.’’
Goodman said comparing the rowing lake’s water take to drinking water usage was ‘‘not a fair and accurate comparison’’, as it implied the lake would threaten Christchurch’s drinking water.
‘‘Our view is there is more than enough water there and it is not the trust’s intention to in any way threaten or hinder the town’s water supply, which appears to be the implication.’’
Hydrologists used by the trust advised 473 million cubic metres of water ran in the aquifer system under Christchurch annually, Goodman said, and the lake would take an estimated 16 million cubic metres annually – 3 per cent of the water available.
Water for the lake could be taken from a separate bore downstream of the council’s water supply, Goodman claimed.
Iafeta said when the extra water was released into the Avon River it would increase its flow by about a third, increasing the flood risk.
The lake would prevent stormwater treatment, Iafeta said. A proposed 31-hectare wetland between Horseshoe Lake and New Brighton Rd would treat stormwater from ‘‘as many as 10,000 properties’’ and improve water quality in the Avon River and Horseshoe Lake.
‘‘In 2017, 83 percent of people surveyed by Nielsen prioritised groundwater quality in the area and 72 percent prioritised water quality in its rivers, streams, lakes and wetlands.’’
Goodman said the trust provided plans showing wetlands around the rowing lake. It received expert advice showing there was room for 38ha of storm water treatment alongside the lake.
The lake’s outflow into the river could be held back during flood events and released at low tide or when water was low, Goodman said.
‘‘The most disappointing thing is the reasons given, and the lack of consultation in respect of those reasons.’’
East Lake Trust commissioned about 15 technical reports worth over $300,000 on the project. Cash grants and donated services funded the reports.
The Ra¯ta¯ Foundation granted the trust $84,000 in February 2017 towards a feasibility study.
Documents filed to the Charities Register show a grant of $20,000 from Sports Canterbury in the 2016/7 financial year.
Regenerate will soon announce a shortlist of options for the red zone in a much-delayed public exhibit. The Crown and Christchurch City Council asked the agency to assess the feasibility of a flatwater facility.
When asked how much was spent researching lake options, Iafeta said Regenerate Christchurch did not intend to discuss development of red zone options until it presented the shortlist for public feedback.