Waka Kotahi NZ Transport Agency said shortly after midday that contractors would be carrying out the repairs this afternoon, warning of delays for motorists in the Otamarakau area.
The tomo formed in the westbound lane on the Waitahanui Stream Bridge between Waitahanui Lane and Otamarakau Valley Rd.
The tomo was repaired by 2.30pm.
A tomo is a shaft formed by water, limestone for volcanic rock and is sometimes referred to as a sinkhole.
Waka Kotahi regional manager of maintenance and operations Rob Campbell said a tomo was typically caused by groundwater eroding the soil and was more common at locations such as bridges due to nearby water sources.
