It was "nowhere near" the point where they would consider evacuations.
"The rate of increase per hour is really slowing down."
High tide is at 4.08pm but Meehan said when the river was in full flood and with great velocity, the tide would not have as much impact.
Westport harbourmaster Mike Charles said it was still raining heavily at 11.30am when the river gauge at Te Kuha was about 9.5m.
The first stage alarm level for flood warning at Te Kuha is 7.4m.
"There's an incredible amount of trees and debris," Mr Charles said.
A high flood water level of 11.8m was recorded in the Buller River in August
1970.
- Greymouth Star