Temporary traffic lights are being set up on Verwood Road near landfill site with work expected to last three weeks.
Hampshire County Council is carrying out drainage repairs to existing systems, ditches and ponds.
Yellow warning signs will be erected to let road users know the exact times and dates the works will take place.
Delays are expected between Verwood and Ringwood, especially at peak times.
And at the time of publication, Station Road in West Moors is blocked following a collision near Tesco Express, with long delays building.