Slips caused by heavy rain have closed the main trunk line in the North Island and forced the occupants out of a Wellington house.
Heavy rain has fallen in parts of the country, including Nelson and Wellington, and was continuing to move north on Thursday night. MetService is forecasting up to 200 millimetres in the Tararua Ranges, Mount Taranaki hill country and Tongariro National Park.
The main trunk line was closed on Thursday evening following a collision between two trains and slips near Wellington.
A passenger train carrying 40 people to Paraparaumu hit a landslip and derailed north of Plimmerton at 3.15pm. A south-bound train carrying 14 people then clipped the cab of the derailed train. Five people were taken to hospital with minor injuries.
KiwiRail subsequently closed the line, which is also the main trunk line, after slips between two tunnels at Ngauranga.
Another slip near Pukerua Bay will also limit services for the next two days.
KiwiRail chief executive Jim Quinn says staff will be working overnight on Thursday to clear the tracks.
Mr Quinn expects rail services to and from Wellington to be limited on Friday and there will be buses for commuters in the morning.
Police say Grays Road near Plimmerton and Paekakariki Hill Road remain closed as a result of flooding and a slip.
They say a slip has also been reported near Normandale in Lower Hutt and contractors have also cleared a slip on State Highway 2.
Occupants forced out of house
The occupants of a Wellington house were unable to return home after a large slip pushed it off its foundations.
The Fire Service was called to the suburb of Melrose about 3pm on Thursday.
The Wellington City Council says it is thought a large section of soil shifted. The house is uninhabitable and the occupants will have to spend the night elsewhere.
Council engineers assessing the damaged property say they also have concerns about a neighbouring property.
South Island roads affected
State Highway 6 at the top of the South Island has reopened after flooding but caution is advised.
Earlier, heavy rain in Nelson and Marlborough closed roads and left rivers swollen, but has since eased.
The Nelson City Council says Kokoroa Road and Manuka Street Ford remain closed due to flooding and slips, but Maitai Valley Road has reopened.