The greater Waiau catchment, including its lakes, receives approximately half of Southlands angling use.
It is one river with two very distinct parts.
The upper Waiau River refers to the river that flows between Lakes Te Anau and Manapouri. This is Southlands largest river and results from the Fish & Game drift counts show it has the most trout per kilometre of all our waterways. It also contains some very large trou, these are mainly residing in the deepest water.
It fishes best in late summer evenings when the caddis hatch. This draws the fish higher in the water column, making them easier to catch in the often fast-flowing current.
The banks are heavily lined with native bush which provides both cover and feed for all aquatic life. However, this makes shore-based angling spots few and far between. It is common practice to fish it from a boat, and some commercial jet-boat operators offer fishing packages.
Bankside access can be made at the Kepler Track carparks, at various points off the Lake2Lake cycleway and via rough tracks from the Manapouri Te Anau Highway.
The vast majority of the water flowing out of Lake Manapouri does so through Meridian Energy’s West Arm power scheme. The remainder passes through the Manapouri Lake Control Structure (aka Mararoa Weir) and goes down the lower Waiau River. Consequently, the lower Waiau River is defined as the river downstream of this control structure and is significantly smaller than the upper.
There is continual debate about what constitutes a healthy flow down this section of the river. Historically, before the construction of the power scheme, the river below Lake Manapouri averaged 450m³s (cumecs), whereas now it has minimum flows between 12 and 16cumecs. A 97% decrease in water volume. So, it is now a shadow of its former self.
The impact of didymo is significant at the top end of the lower Waiau however is less noticeable further downstream. The river is a manageable size and wadable however care must be taken as it is very slippery.
Warning: The water level in the lower Waiau can rise rapidly. Under certain conditions Meridian Energy release a ‘flushing flow’ down the river to slough didymo build up off the riverbed. For updates on these, check or follow Meridian Energy and/or Southland Fish & Game on Facebook.
Access is limited through these reaches, however anglers who are prepared to do the leg work can rest assured that they will have solitude when they get there.
These remote areas of both the upper and lower Waiau can have particularly great fishing during a ‘mouse year’. Anglers wanting to target these large, predatory trout, should be searching out pools that have native trees either overhanging, alongside or upstream of them. Imitation mice patterns can be fished either during the day or night, with either spin or fly gear.
The Monowai River adds a significant volume of water to the river and below this confluence boat access is possible.
Unlike other Southland rivers, the Waiau does not have a long estuary. However, it has a large lagoon that holds a good population of brown trout. Late winter and spring provide the best fishing here, especially early or late in the day using small baitfish imitations.
The Waiau River, is the only river in Southland where an angler can target brown trout, rainbow trout and chinook salmon (November – March).
All accesses can be found here.
Notable tributaries of the Waiau River include.
Note: These are only the main tributaries that flow directly into the Waiau River. There are numerous other rivers/streams in the catchment that flow into the lakes, and then into the Waiau which are not listed here.