Motorists face delays of up to 45 minutes as a storm-damaged section of State Highway 1 south of Ashburton is rebuilt from Monday.

Work on Hinds Highway, between Thews Road and Longbeach Road, will begin on September 14 after heavy rain in July caused widespread potholes.

NZ Transport Agency said water had infiltrated the road seal, damaging the highway. The work will stabilise and rebuild the affected section before new chipseal is applied, making it more durable and resistant to rutting and potholes.

The highway will be reduced to a single lane from 6am on Monday, September 14, until 6am on Friday, September 18. Traffic will be stopped as required, and a temporary 30kmh speed limit will apply.

Drivers should allow for delays of up to 45 minutes during peak daytime periods and up to 20 minutes at night.

Both lanes will reopen from 6am on Friday, September 18, until 6am on Monday, September 21, although the reduced speed limit will remain.

Single-lane restrictions will return from 6am on Monday, September 21, with traffic again stopped as required.

Two lanes are expected to reopen from Tuesday, September 22, but the temporary speed limit will remain for a couple of days while the new chipseal beds in.

NZ Transport Agency urged motorists to plan ahead and allow extra travel time.

Access to properties may be affected at times, with roading crews available to help residents with specific access needs.

The work has been scheduled to take advantage of a forecast window of suitable weather. Any changes to the programme because of weather or other factors will be notified.