Damage to roads and riverbanks in Marlborough in the aftermath of Cyclone Ita will be around $1 million.
Marlborough District Council on Monday announced the cost of repairs which are expected to take about three months.
It said the worst damage to roads was in the Awatere Valley Road where shingle and debris ripped away surfaces.
Port Underwood Road also requires major repairs due to slips and drop-outs, and three retaining walls will have to be rebuilt before the Tumbledown Bay Road can be reopened.
Roads assets manager Steve Murrin said Port Underwood Road also needs major repairs due to slips and drop-outs, and three retaining walls will have to be rebuilt before Tumbledown Bay Road can be reinstated.
Major work is also required on the Taylor River floodway in Blenheim and the Waikawa Stream outlet in Picton.
Mr Murrin said Marlborough Roads will make an emergency works claim to the Transport Agency for the bulk of the costs.