Coastal Engineering in Whanganui
Whanganui meets the sea where its river reaches the South Taranaki Bight, and that river-mouth coast sets its coastal engineering apart. The open coast here is a long, exposed, sandy and gravelly shoreline driven by westerly swell, the river entrance carries training works and a long maritime history, and the low ground near the river and coast is exposed to flooding from both sea and river.
LDE’s team brings coastal and marine engineering to this setting, with seawall and revetment design, coastal erosion and hazard assessment, river-mouth and foreshore structures, and sea-level-rise and surge resilience for low coastal land. We help the district, landowners and operators manage a coast where a major river meets an exposed shore.
For Whanganui, that means coastal advice grounded in the real behaviour of a river-mouth coast.
How our Whanganui team delivers coastal engineering
A long, exposed open coast and a major river mouth make erosion, surge and entrance works the defining coastal issues in Whanganui. Our team assesses swell, surge and erosion exposure on the sandy and gravelly shore, then designs seawalls, revetments and foreshore structures suited to a high-energy coast. At the river entrance we assess training and bank conditions, since river flows and coastal action work together, and on low ground we factor coastal inundation into design.
It is the same coastal and marine engineering capability behind our ports and marine work, alongside the water and flood experience this coast demands.
- Coastal erosion and hazard assessment on an exposed open coast
- Seawall and revetment design for sandy and gravelly shoreline
- River-mouth and foreshore structures where the Whanganui meets the sea
- Coastal inundation and sea-level-rise planning for low coastal land
Coastal hazards and consenting in the Whanganui area
Coastal work around Whanganui is shaped by Horizons Regional Council coastal plans and natural-hazard information, with consents through Whanganui District Council. We align assessment and design with that framework and national coastal policy.
- Ministry for the Environment coastal hazard and RMA guidance
- Maritime New Zealand navigation and river-entrance safety
- Natural Hazards Commission Toka Tū Ake coastal erosion and inundation research
LDE on the Whanganui coast
We bring coastal and marine engineering to Whanganui’s river-mouth and open-coast settings, from shoreline protection on an exposed coast to structures where the river meets the sea. You can explore more of our regional delivery on the projects page, and read about our ports and marine capability nationally.
Common questions about coastal engineering in the Whanganui area
What defines coastal engineering at Whanganui?
A long, exposed open coast and a major river mouth meet here, so erosion, surge and river-entrance works all feature. Coastal structures and protection have to account for river flows and sea conditions together.
How do sea and river flooding combine near the coast?
High seas and storm surge can hold back river drainage at the mouth, worsening flooding on low ground. We factor coastal water levels into how low-lying coastal land and its protection are designed.
Who leads LDE’s Whanganui coastal work?
Chartered Professional Engineers from our team, supported by LDE coastal and marine specialists nationally.
Can LDE design protection at the Whanganui river mouth?
Yes. A river entrance needs works that manage both the river flow and coastal wave and surge action, so we assess the combined conditions and design training, revetment or bank protection to suit. On a coast defined by its river mouth, this combined view is essential to durable, consentable protection.
Whanganui / Manawatū
