The constant rain warnings — which often result in little more than surface flooding — have been the bane of the tourist sector.
As a result of the change there will be far fewer orange warnings, as many rainy days that would previously have triggered a weather warning will now be a yellow watch.
The new warning criteria for Westland is 150mm in a 24-hour period, or 80mm in six hours. Previously it was 100mm in a 24-hour period or 50mm in six hours.
The change reflects the higher rainfall experienced on the West Coast compared with other parts of New Zealand.
West Coast Emergency Management group manager Claire Brown said it had been under discussion for some time.
In parts of the Westland district, 100mm of rain was not significant, whereas in other parts of the country that would have more impact.
People had become complacent with the number of orange alerts, she said.
Now it had been adjusted, it was important people looked at the warnings carefully.
Gerry McSweeney from the Wilderness Lodge at Lake Moeraki said while the Coast was getting lots of heavy rain at the moment, it was moving through quickly.
"It’s not stalling and dumping huge volumes, and that’s good news.
"Rain keeps forest growing, rivers flowing, hydro going." — Greymouth Star