If dry conditions continue, it is predicted the effects on the Taieri River will be worse than in previous dry years.
There were water restriction alerts at three of the five monitoring sites on the river, and last week the Otago Regional Council put a water shortage direction on the Paerau to Waipiata section of the river, rationing and rostering water takes on that stretch, affecting three farms.
Council chief executive Peter Bodeker said farmers should be implementing plans to deal with the longer-term effects of water shortages on their properties.
''We appreciate the co-operation we've had so far from many farmers in difficult circumstances.''
The Taieri River was a special case as the majority of water takes were ''deemed or mining takes'' which were not subject to the minimum flows imposed under resource management consents to protect the ecology of rivers.
While restrictions had come into force on the upper Taieri River, the level at Outram was just sitting above its minimum flow of 2.500cumecs at 2.985cumecs.
When the minimum flow of a river was breached, all consented takes linked to that site had to stop immediately.
The lack of rainfall meant most places on the Taieri River had been safe to swim in since mid-December as bacterial contamination generally occurred after rainfall when rural run-off entered the water.
At Outram, the river had been under action levels at each test so far this summer except on December 1.
Monitoring at Lake Waihola also showed it had been safe to swim in all summer.
However, the Taieri River at Waipiata had a history of high E. coli results, some of which were not related to high rainfall events, which the council had been investigating.
So far this summer, it had reached amber alert levels once, on December 11, and action levels on December 29.
Taieri River
• Has a catchment of 5700sq km.
• Flows 318km from headwaters in Central Otago.
• Flows out to sea 30km south of Dunedin.
• More than 100 consents to take water from the river and tributaries.
• Majority are ''deemed'' or ''mining permits'' from the gold rush days.
• Minimum flows set for five sites on Taieri.
