In addition the turf was irrigated before any games to create better playing conditions, and if the weather was very hot extra irrigation may be added during breaks in the game, he said.
The festival will be held between March 31 and April 9 this year.
The Horse of the Year begins at the Hawke's Bay showgrounds on March 7 and showgrounds general manager Brent Linn said a programme of ground preparations for competition-ready surfaces was well underway, with regular irrigation of the competition arenas.
Extra casual staff had been brought on to help with other aspects such as mowing and preparing rails.
He said last week's rain helped put a green tinge on unirrigated areas of the 45-hectare facility, and the lower temperatures had offered some respite and helped with water retention.
"We are on track to have it game-ready by the time it starts, but we are an outdoor venue and we need to accept that we don't have perfect control over the environment - there's always a bit of a risk.
"The competition surfaces need to be prepared so both the horses and the riders can perform at their optimum and there is a safety aspect to it as well."
Although the show had to go on, he said the prospect of heavy rain meant organisers would be faced with more remedial action after the event than if it was fine.