The popular river race was the first event to be dropped after Whibley checked out the course and then promptly drowned his Yamaha.
But, even with an abbreviated schedule, the racing that did go ahead was worth every penny.
Honda's McDonald was beaten to the chequered flag in both the MX1 races - won instead by Bay of Plenty man Townley - but, significantly, it was McDonald who won the one-off feature race, the Invitation International race, therefore claiming the prized Woodville trophy.
He beat Gisborne's Shaun Fogarty (KTM) and Hamilton's Darryll King (Yamaha) in the feature race after Kawasaki's Townley, at that stage running in second spot, succumbed to the slippery track, crashing his bike and eventually withdrawing.
"For the first three laps I kept the throttle pinned to the stop, but when my pit signals told me Townley had crashed out, I backed it off and cruised to the win," said McDonald.
Only 12 of the 27 starters finished the feature race and only the top three riders completed 10 laps.
It was certainly a consolation that Townley won both the MX1 class outings earlier in the day.
The event was the Kawasaki rider's farewell to New Zealand, the 25-year-old thrilled to be able to declare his two-year battle to recover from injury was finally over and that he was now ready to rekindle his international career.
He will take up a new contract to ride for Honda and heads to Europe and the United States, to contest the first three rounds of the motocross world championships, in Bulgaria, Italy and the Netherlands in April, and then the motocross nationals in the US, set to kick off in May.
"It's fantastic to come here and win races," said Townley afterwards. "I have not raced at Woodville since I was about 13 or 14.
"Of course I was disappointed not to win the main race but the two MX1 race wins were still good for me. I wanted to test my speed and fitness today but the conditions wouldn't allow that. At least I finished the day still healthy and fit."
The MX2 (250cc) class on Sunday was won by Hamilton's Jesse Wiki (Honda), while Auckland's James Ainsworth (KTM) won the 125cc class and also claimed the under-21 crown.
For the supremely fit King, it was a remarkable display of strength, speed, skill and stamina. The 42-year-old five-time former Woodville winner won the veteran's class as well as finishing runner-up to Wiki in MX2 and coming home third in the feature race.
Meanwhile, Saturday's junior racing had gone ahead in contrasting conditions, dust billowing from the sun-baked Woodville terrain. Outstanding performances came from Rotorua's Scott Canham (Kawasaki), Rangiora's world junior 85cc No8 and national 85cc motocross and supercross champion Micah McGoldrick (KTM), world junior 85cc champion Jay Wilson (Australia, KTM), Cromwell's Sam O'Callaghan (Honda), Mangakino's Kayne Lamont (Yamaha), national junior 125cc champion Dion Picard (Atiamuri, Suzuki), Oamaru's Joel Miekle (Honda), Silverdale's Claude Griffith (Yamaha) and Otago's world junior 85cc No6 Courtney Duncan (Yamaha).
