The Narrows Bridge at Tamahere will be closed on Wednesday, April 20 for much of the day.
The NZ Transport Agency (NZTA) is closing the Airport Rd/SH21 bridge across the Waikato River while it removes the adjacent, temporary bailey bridge.
The river crossing will be closed from 9.30am to 5pm, said NZTA State Highways manager Kaye Clark.
A two-hour stop/go operation will also occur early on Monday morning, April 18 from 4.30am for lane markings to be painted on the Narrows Bridge in the lead up to the temporary bridge removal.
While the bridge is being removed on Wednesday, people travelling to Hamilton International Airport on Airport Road from the Tamahere side of the city are advised to allow approximately 30 more minutes for their journey. The recommended alternate route to and from the airport is via SH3 (Ohaupo Road). Detour signs will be in place.
The bailey bridge was installed to enable river bank strengthening and stabilising to take place beneath the Narrows Bridge.
Clark says the Narrows Bridge itself is structurally sound. The strengthening of the riverbanks beneath involved drilling around 75 holes in each bank, 100mm in diameter, to a depth of 18 metres. Once the holes were drilled a reinforcing bar was installed in each one and the hole filled with cement grout. The faces of the river banks were then covered with concrete to protect them and prevent further erosion as river levels rise and fall.