Southland region

Throughout its length, the Mararoa is a fast flowing river, with powerful runs and deep pools. The swift current of the river, as well as the large cobble substrate, provide great habitat for rainbow trout, which the Mararoa is renowned for amongst fishermen. Near the Mararoa River’s natural confluence with the Waiau River, the Manapouri Lake Control now diverts the water from the Mararoa back into Lake Manapouri, excepting when the Mararoa River is in flood. This is to augment the flow required by the Manapouri hydropower station. Environment Southland has no water level recorders on the Mararoa River but the Mararoa River is monitored for flow by NIWA on behalf of Meridian Energy, near the Manapouri Lake Control. An automatic rainfall recorder is located near the Whitestone River at the Te Anau-Mossburn Highway. NIWA also runs a raingauge site further up in the Mararoa catchment. The Mararoa surface water zone is one of the few fully allocated management zones in Southland. This is due to hydroelectric power generation activities in the Waiau River catchment. A small number of rural community water supplies are also sourced from the lower Mararoa River.