Mohaka Catchment

Mohaka Catchment

The Mohaka catchment covers the Mohaka and Waihua River catchments. Mohaka River rises in the Kaimanawa Ranges, is bound by the Kaweka and Maungaharuru Ranges to the south and east and flows into Hawke Bay near the Mohaka settlement. The Waihua is a smaller catchment to the north. Geologically, the upper catchment features both hard rock (greywacke, volcanic ignimbrite) and pumice. The lower catchment is mostly soft sedimentary rock. The climate tends to be wetter and colder than the regional average. 

Mohaka River is recognised nationally for its outstanding trout fishery, exceptional whitewater recreation opportunities and stunning landscapes. Above Willow Flat, a Water Conservation Order prohibits most damming, and other water uses must not detract from the river’s outstanding characteristics and features.

Indigenous forest covers about half of the catchment, along with exotic plantation forestry, manuka/shrubland and exotic grasslands. There are some natural wetlands in forested areas. A third of the catchment is under some form of formal protection, such as Nga Whenua Rahui or as DOC conservation areas. The frost flats of the Ripia and Waipunga valleys are nationally-rare ecosystems. Some threatened bird and plant species are found here, including whio (blue duck), kaka and long-tailed bats.  

The main productive land uses are plantation forestry, and sheep and beef pastoral activities. There is a significant area of dairying in the Taharua catchment and orchards near the coast.

There are no towns in the catchment rather small rural communities at Taharua, Puketitiri, Te Haroto, Te Pohue, Kotemaori, Raupunga and Mohaka. Only Raupunga has a registered drinking water supply. There are substantial blocks of Māori Trust land, some of which is managed under Ngā Whenua Rāhui agreements with the Department of Conservation.

Known Issues

We know that the Mohaka catchment faces the following issues:

• Degraded water quality – where farming leads to elevated nitrogen concentrations in the Taharua River, fuelling nuisance algae (periphyton) growth; this affects ecosystem health below the confluence with the Mohaka River, and reduces Mohaka’s value for water-based recreation
• Forestry slash and logs – creates safety hazards for recreational users, clogs water flow, destroys amenity values along the waterways and coastal foreshore
• Excessive sedimentation on the lower Mohaka River – poor visibility, degraded cultural and amenity values, smothered aquatic habitat, adversely affected drinking water supplies
• Livestock in rivers – degraded water quality, bed disturbance, damage to riparian margins and vegetation
• Public access - includes poor infrastructure (access and toilets) – environmental damage, detracts from use and enjoyment, also at the river mouth
• Biodiversity – retaining valued remnant indigenous vegetation, improved riparian margins and wetlands, plant and animal pests such as goats and possums, spray drift, generating multiple ecological, water quality and pest reduction benefits
•  Customary Rights and Treaty issues - resolve access to and management of valued natural resources by tangata whenua, and gravel management including hangi stones.

Your feedback

The following infographic displays what the community has told us about this catchment in our first round of engagement.  For more information read the full Kotahi Community Engagement Report here.