The Clutha/Mata-au is the largest Freshwater Management Unit in Otago, and encompasses the full extent of the river catchment, from the mountains to the sea.  

This area has been divided into five sub areas called “rohe” to enable meaningful consultation with different communities in the area, and to ensure a more localised approach to decision-making.


Clutha Mata-au main stem map


Clutha Mata-au main stem 

This summary paper provides an overview of the environmental flows and take limits relating to the main stem of the Clutha Mata-au, Kawarau River and Hawea River main stems.  

The “Cutha Mata-au main stem” includes the  

  • Hawea River from Lake Hawea Dam Outlet to the Confluence with Clutha Mata-au
  • Kawarau River from outlet of Lake Whakatipu to the Confluence with Clutha Mata-au arm of Lake Dunstan 

A map of the Cutha Mata-au main stem is shown below.

map of the Clutha Mata-au main stem fmu showing boundaries

Setting take limits and environmental flows

The Clutha Mata-Au main stem is a high valued and unique water body. There are many values present and other matters that will inform the setting of take limits and environmental flows, these include:

  • High natural character and unique river form
  • The Kawarau River and parts of the Clutha Mata-Au main stem have been identified as a potential Outstanding Water Body
  • Water Conservation Order on the Kawarau River
  • High recreational values
  • Ecological habitat/flow relationship is in reverse and not the key driver for setting EFL and take limit (less water means more habitat)
  • Renewable electricity generation 
  • Water quality and the requirement to maintain or improve where degraded


Draft proposed environmental flows

It is proposed to retain existing environmental flow regime as established by the conditions of the resource consents held by Contact Energy Limited for operating hydro-electricity generation infrastructure at the Lake Hawea outlet and the Clyde and Roxburgh dams.

The draft proposed environmental flows for the Clutha Mata-au, Kawarau River and Hawea River main stems are shown in Table 1 below.

Draft proposed take limits

Two options have been developed for setting take limits for the Clutha Mata-au main stem, the Kawarau River and the Hawea River.