A slip is blocking the southbound lane on Thames Coast Rd, north of Whakatete Bay, between Tapu and Thames.
SH30 between Tikitere and Lake Rotoma was closed due to fallen trees but has since reopened with traffic management in place in some locations, Waka Kotahi said in a statement.
Police said slips had also blocked the road earlier.
It follows downpours in the region last week that trapped motorists on the Kaimai Range and overwhelmed Rotorua’s wastewater system at several points.
MetService meteorologist Mmathapelo Makgabutlane said a yellow heavy rain watch was in place until 3pm in the Bay of Plenty and Rotorua and between 8am and 11am in the Coromandel.
She said it had been “a very wet year so far” and most of the North Island was already “very saturated”.
“Which means that it doesn’t actually take that much rain for some of those impacts to be seen.”
Impacts included possible flooding, slips, hazardous driving conditions and poor visibility, she said.
Makgabutlane said thunderstorms were also expected in the Bay of Plenty and Rotorua this morning. They would be confined to the Eastern Bay of Plenty by the afternoon.
“As we’ve seen recently, thunderstorms tend to bring a very heavy burst of rain over localised areas in a very short space of time,” she said.
“We’re expecting this widespread rain but within that, we could see pockets of more intense rainfall.”
Makgabutlane said with a low-pressure system moving through from today, there would be “quick strong winds”.
She said people should prepare by moving outdoor furniture inside or tying down trampolines.
Makgabutlane said there was the potential for “severe gales” reaching up to 100km/h in exposed areas.
Compared with last week’s heavy rain, Makgabutlane said the system would be moving through “fairly quickly”.
“We’re not expecting it to linger in any one area for a long time.”
The heavy rain was expected in two waves, the first starting Friday morning.
“Then we do actually expect a bit of an easing. We could see more like showery conditions rather than that persistent rain for the latter half of tomorrow and then into Saturday, we would expect that next band of showers and rain to start coming through.”
The second half of Sunday should bring “clearer weather” with the bulk of the rain having passed by then, she said.
She advised people to keep up to date with the latest rain watches and warnings as MetService was constantly reviewing them as information became available.