Waikouaiti River

The catchment has indistinct boundaries for the most part, with no dividing ranges between it and neighbouring catchments. To the west it is bordered by the Nenthorn stream catchment, Three O’clock stream catchment and various other small catchments that drain to the lower Taieri River. To the north and east it shares headwaters with the Shag and Pleasant Rivers and to the south it is bordered by the Silverpeaks.

The average annual rainfall in the upper catchment is 740mm rainfall, in the lower catchment (Palmerston) it is 545mm.

Vegetation in the catchment has been considerably modified over the last 150 years. Extensive forest and tussock areas have been replaced by a mixture of high- and low-producing grasslands with scattered areas of remnant broadleaf and native and exotic forest. In the uplands beyond the confluence the pasture is mostly low producing with both native manuka/kanuka and introduced scrub in gullies. In the Silverpeaks, in the headwaters of the south branch, some native manuka/kanuka and broadleaved indigenous hardwood forest/scrub remains.

High producing pastures predominate in the hills and downs, river flat areas in the lower catchment below the confluence. The Waikouaiti estuary supports the largest remnant saltmarsh system in Otago, and is listed in the Water Plan as containing a scarce wetland type containing glasswort and jointed rush.

The Waikouaiti River is used extensively for whitebaiting between August and November, with inanga, koaro and banded kokopu all contributing to the whitebait catch.  The Waikouaiti River supports one of the most diverse freshwater fish communities in Otago, with 11 native and one introduced fish species present. Black flounder and yeloweye mullet are also common in the lower reaches of the Waikouaiti River. The river also supports a locally significant brown trout fishery, and is especially well known for its population of large sea-run brown trout in its lower reaches.

During the summer there is weekly monitoring at Bucklands.

This site was suitable for swimming on most of the occasions sampled.

Our data tells us that the source of bacteria is ruminant (sheep/cows), and therefore we recommend you stay out of the water for 48 hours after rainfall or after high river flows to avoid swimming in rural-run off that can contribute to high bacteria concentrations.