Hoteo River Kayak
What do kayaking and river bank erosion have in common?
The Hoteo River is situated in the Northwest of Auckland and flows from Wellsford to the Kaipara Harbour. It is the longest river in Auckland and has the biggest catchment occupying roughly 9% of the Auckland region. The river traverses through steep hill country which is predominantly farmed before discharging through a long tidal channel by the Mangakura boat club on state highway 16.
The Stormwater Unit has commissioned Dr Andrew Simon, geomorphologist from CARDNO ENTRIX to undertake analysis of erosion potential and sediment loads associated with the river’s banks. The catchment has been flown by a helicopter to give the scientist a broad overview of the area and photographic record of reaches subject to erosion. In an effort to gain more detailed information a number of council staff, scientists and other interested parties kayaked the lower section of the river. Information on the percentage of active stream bank erosion was recorded on GPS referenced video.
All up about 20km of river was kayaked in 5 hours with a brief stop for a well-earned lunch break. Kayaking the river gave a great perspective of the river’s characteristics and the low water levels allowed the toe of the river banks to be inspected. The next phase of the research is to undertake detailed bank analysis at specific locations down the river. This information will be run through models to quantify sediment loads and erosion rates. Options with associated benefits and costs will be developed aimed at mitigating erosion and improving the water quality in both the Hoteo River and the wider Kaipara Harbour.
This research complements other work being carried out in the Hoteo Catchment by the Sustainable Catchments Programme (Environmental Services Unit) to better understand the Hoteo environment and people and to plan a catchment wide programme. It demonstrates the power of multiple teams – CLAW, stormwater and ESU working together towards the same objectives.