Emergency repairs were underway, but SH1 between Paekakariki to Pukerua Bay remained down to one lane on last evening causing significant traffic delays.
Heavy machinery was to cart an estimated 350 tonnes of rock to reinstate the seawall but it was unclear when this work would be completed.
NZTA said the road would remain with only one lane "until further notice".
Elsewhere around the country more roads remained closed.
SH11 from Paihia to Kawakawa in Northland was closed due to slips.
In Wanganui/ Manawatu SH3 from Ashhurst to Woodville and Canterbury's State Highway 1 from Goose Bay to Ferniehurst was also closed due to slips.
In Otago SH90 from Tapanui to Waikoikoi was closed due to flooding.
The small Golden Bay town of Takaka, a popular tourist destination, was cut off by several slips on SH60 from Riwaka to upper Takaka.
Several shops in the town were quickly cleared out of essential goods as residents and visitors stocked on essentials.
Milk, bread, canned goods and toilet paper were the first to go as people rushed to the supermarket, Fresh Choice manager Roger Pait said.
"The shop was chocker you couldn't even move around."
On the Spot shop owner Craig Bishop-Everett said "we have run out of bread and milk, we are trying to organise a barge, it may or not happen".
Soy milk, milk powder and all other varieties of milk that the store stocked were gone as well.
Nelson Tasman Civil Defence had arranged for a delivery of food and essential supplies by barge to Port Tarakohe , which was due by early this morning.
The limited fuel supplies in the district were being managed with a restriction of $30 of fuel per vehicle per day.
In Taranaki, New Plymouth residents were being given water from tankers after a treatment station to the Mangorei Reservoir was ruptured by a falling tree during winds of up to 140km/h.
A boil water notice was also in place.
Residents in New Plymouth, Bell Block, Waitara, Tikorangi, Onaero and Urenui were being urged to minimise water use.
While the clean up was far from over, the worst of the weather had passed by yesterday afternoon.
Some rain was expected in parts of the country over the next day or so, but would clear for most by the end of the week.