"Two weeks before the flood, the survey found there were huge amounts of eggs and chicks and that this breeding season was a successful one," she said.
"Any nests or chicks in the river channel when the rain came would have been washed away and drowned.
"We're gutted the birds now have to start again. But these birds are resilient and determined," she added.
Hashiba said survey workers walked more than 1200km in Hawke's Bay to gather data for the assessment, spanning the three catchment areas.
The ecologist expert said banded dotterels, oystercatchers, black-billed gulls and pied stilts are the main birds found along the rivers, but all river birds need protection.
"We're already seeing lots of nests popping up along the rivers. Fingers crossed they get this lot of chicks through," she said.
"Predators, especially hedgehogs, feral cats and ferrets, are the biggest threat to these birds, but weeds and human activity are also a danger to them."
Hashiba reminded the public that if you're heading out on the region's rivers, please limit your driving to a minimum and keep your dogs under control.
"This will go a long way to helping out our feathered friends."
