Saturday's 104th North Hokianga A&P show at Broadwood has been cancelled.
Secretary Susan Douglas said committee members had walked the grounds yesterday morning, and had agreed unanimously that the event could not proceed.
"If we didn't have the horse jumping events, chopping, shearing and car parking we could go ahead, but then we wouldn't have much of a show," she said.
This week's rain had been the final nail, but had simply been the latest contribution to an extremely wet start to the year. More than 400mm of rain had fallen at Broadwood over the last six weeks, reducing parts of the grounds to a quagmire.
Rain and the Broadwood show often went together, Mrs Douglas added, but traditionally it had fallen before, or during, the event after a long dry spell. That was not the case this year.
Lower parts of the grounds had been under several metres of water on Tuesday.
Mrs Douglas said the cancellation was not unprecedented, although it had probably been 25 years or more since such a decision had been made.
Entry fees would be refunded; exhibitors and competitors should contact show secretary Helen McCready by phoning (09) 409-5857, or emailing firstname.lastname@example.org if necessary.