By John Gibb
Any redevelopment of Forbury Park racecourse would offer a "huge opportunity" to strengthen South Dunedin's overall defences against flooding, scientists say.
Traffic moves along a street in South Dunedin that flooded in June 2015. Photo: RNZ / Ian Telfer
Strategic options for the site include a sizeable temporary water holding area, separated from ground water, and a pumping station to drain it; or a specially designed wetland, they say.
Using part of the large park site, such features could help protect South Dunedin houses from flooding such as occurred in 2015 after unusually heavy rain.
The water-holding features could prove crucial in overall flood protection, given South Dunedin lacks a natural river or stream to move any excess surface water arising from unusually heavy rain.
GNS Science principal scientist Dr Simon Cox, of Dunedin, said the park site, in association with Bathgate Park and Tonga Park, offered "a huge opportunity to provide potentially cheaper options for managing flood water", including a possible temporary holding area.
The Forbury Park Trotting Club last month announced plans to sell its park and relocate to either a Dunedin greenfields site or Wingatui.
The Forbury Park Trotting Club announced plans to sell its park last month. Photo: Forbury Park Trotting Club
Engineering geologist Dr Hugh Cowan said yesterday any redevelopment of the park should take into account flood resiliency, and recent South Dunedin hydrological research findings.
Dr Simon Cox Photo: Supplied
Dr Cowan, who is a former resilience general manager at the Earthquake Commission (EQC), was among 250 people attending the New Zealand Geotechnical Society's latest conference, which ended in Dunedin yesterday.
He also gave an open lecture, on natural hazard risk and promoting resiliency.
Dr Cowan highlighted recent South Dunedin hydrological research supported by a consortium, including the Otago Regional Council, the Dunedin City Council and GNS Science and led by Dr Simon Cox, of the GNS Dunedin office.
In trying to build greater resilience, good science and "engagement among diverse interests" was crucial for success, he said.
Drs Cowan and Cox said it was crucial that the community had a further say over the future of Forbury Park.