"Luckily, we got to the hives just before the big flooding event, but we haven't been able to get back to them since."
He had heard of other beekeepers in a similar situation, especially around more remote areas of the Marlborough Sounds, he said.
Typically he would check his hives every few weeks, and at this time of year it was important to manage the bees properly and check for disease, he said.
"You've got to stop them from getting too strong or they'll swarm on you, which you don't want to happen, and they can starve if they run out of food, if they go through a period of not having much food, you've got to look after them for that reason as well.
"Over winter, you can leave them for a few months, but at this time of the year, they're moving quite quickly, they're building up bee numbers, and they're going through a lot of food."
It was crucial to get to the hives soon to prevent lasting impacts on the season, Elwood said.
Some of their hives were in very remote areas, but they could trek to them if road access was not restored, he said.
Elwood hoped to check in on the isolated hives next week.
- RNZ