Hazards and navigation safety events
Here you'll find current information about hazards and navigation safety events in the Canterbury region.
Navigation safety alerts are short-term warnings about temporary or changing risks on the water, issued when conditions are unsafe or unpredictable.
Notified hazards are known, ongoing hazards that are permanently or regularly present in a waterway. They do not include everyday risks that a prudent skipper or boatie would normally expect and watch for. This information is not an exhaustive list of all hazards that may be present.
Report a boating incident, accident or hazard: Report unsafe behaviour, accidents or hazards on the water to our Harbourmaster's Office. For urgent issues, call 03 328 9168
Current navigation safety alerts
Railway iron in the Ashley River
12 October 2026
A large railway iron has become exposed in the middle of the main current on the Ashley River just under the State Highway 1 Bridge.
Please navigate with caution.
Sunken navigation safety hazards - Akaroa
12 October 2026
There are multiple sunken navigation safety hazards in the Akaroa Harbour. Warning buoys have been installed.
Please navigate with caution.
Railway irons in the lower Waimakariri River
5 October 2026
Exposed railway irons have been found in the lower Waimakariri River.
Please navigate with caution.
Fence wires in Waipara River
7 May 2026
There are exposed fence wires stretched across the Waipara River following recent flooding in the area.
Please navigate with extreme caution.
Approximate location of the exposed fence wires across the Waipara River
Concrete blocks in Rakaia River
7 May 2026
- Concrete blocks are located in the Rakaia River (true right, downstream of Dobson Ferry Road)
- Please navigate with caution
- Works are planned for winter to relocate the blocks
Location of concrete blocks in the Rakaia River downstream of Dobson Ferry Road
Various waterways in the Canterbury Region
Fluctuating water levels on various waterways, including rivers, lakes, and lagoons in Canterbury may result in fences, waratahs, or other objects being obscured from view and sitting below the surface. All water users are strongly recommended to exercise caution and keep your speed to 5 knots or less within 200 metres of the shore, unless the area is uplifted or has any other form of speed exemption. It is the responsibility of the skipper of the vessel to ensure that the area you are using is navigable and safe to transit.
Lower Clarence River / Waiau Toa - navigation safety hazards - sputniks
Sputniks are large concrete blocks with protruding steel beams that were historically used on rivers for bank protection. Many still exist on some rivers, including several in the lower Clarence / Waiau Toa, some of which are navigation safety hazards for those boating the river. For more information see the Sputniks notice (PDF 710 kB).
Brooklands Lagoon - submerged objects
Submerged and semi-submerged objects including tree stumps have been reported in the Brooklands Lagoon water ski area. Users of this area are advised to exercise caution as these objects may be difficult to see, particularly if navigating at towing speed.