What are rail irons? 

Rail irons are steel beams historically placed in rivers for erosion control and debris management. Many have shifted, become buried, or recently been exposed by erosion and high flows. These hidden structures pose serious risks to jet boaters and other river users. 

Four rail irons sticking up out of the water, across the width of a river
A rail iron sticking up out of the water of a river at and angle
Three rail irons sticking up out of the water of a river

Why they matter 

Rail irons can sit just below the surface and be difficult to see, especially after flood events. Hitting one can cause serious injury or death.  

Where the risks are highest  

Known hotspots include several Wairarapa rivers, particularly the Ruamāhanga and Waiohine, where rail irons are present and jet boating communities are active. Rail irons have also been spotted in other rivers across the region, including the Ōtaki River in Kāpiti, so keep an eye out wherever you are. As rivers shift, more previously buried irons may reappear. 

What to do if you spot one 

  • First, stay clear!   
  • If it’s safe to do so, take photos of the rail iron. 
  • Make a note of its location on the river. 
  • Report it to Greater Wellington as soon as you can using the form below so it can be recorded and removed. 

What else you do can to help 

Stay alert after high flows, always look out for potential hazards, and share this information within your boating community. Every report contributes to safer rivers for all recreational users. 

Report a rail iron now

Updated March 25, 2026 at 4:25 PM

Get in touch

Phone:
0800 496 734
Email:
info@gw.govt.nz