"I'm definitely looking to win, as I always am when I go into these races but, in saying that, everyone who is going to be down there is a quality swimmer and on their day could have a great day. You just never know," Radford said.
In the absence of Olympian Melissa Gorman (Australia) and New Zealand champion Cara Baker, the elite women's field is wide open.
This event will mark, almost to the day, the one year anniversary of the devastating earthquake that struck the Canterbury region.
Event director Scott Rice said it will be an emotional time for all New Zealand, especially the people of Christchurch, and felt it was important to provide a way for people to come together and share a fun day out.
"It's a real privilege to still be hosting an event in Canterbury for the first time since the earthquakes," he said. "We understand that for many people it is still a day by day struggle so any form of escapism or entertainment we can provide will hopefully be well received."
La Grande Swim organisers have arranged for a 50 per cent discounted entry fee for anyone living in the Canterbury region.
Around 800 swimmers are expected to take part in Sunday's event in four race distances, the 2.8km swim, two middle distance options of 1000m and 300m, and a well supervised kid's race of 200m.