"We are seeing some excellent examples of collaborative water management, particularly in the Upper Taieri where they have implemented some excellent measures for the benefit
of the rivers.''
ES director of science and information Graham Sevicke-Jones said low flows in both the Oreti River and the Mataura River had triggered water restrictions in Invercargill, Bluff, Mataura and Gore.
Other rivers and aquifers were very low and a sustained period of rain would be needed for them to return to normal, Mr Sevicke-Jones said.
Rain forecast for later in the week would be welcome but its effect would be relatively short-lived.
"Apart from the rivers, the rest of the landscape will return quite quickly to the conditions it's got now, but we'd expect the rivers to drop quite quickly.''
It was unlikely the rain would recharge bores and aquifers to a significant level, he said.
Water restrictions remain in place in parts of the Queenstown Lakes, Clutha and Waitaki districts and the Dunedin City Council (DCC) is still asking residents to reduce the amount of water they use in an effort to avoid restrictions.
DCC group manager 3 Waters Tom Dyer said at this stage the council did not need to enforce formal restrictions as demand had dropped to a sustainable level.
A total fire ban remains in place across Otago and Southland and Fire and Emergency New Zealand is warning today could be a particularly high-risk day in Central Otago and the Queenstown Lakes area.
Dry rivers were also causing issues for fish as the number of strandings was on the rise across Otago.
Otago Fish & Game operations manager Ian Hadland said there was little that could be done to save the schools of fish already in trouble.
"Where we can we will relocate them but as you can imagine the fish that get trapped are already quite stressed and removing them puts them under even more stress.''
Where it was possible and safe to do so, fish would be transported to another body of water, he said.
People who noticed stranded fish should report them to either Fish & Game or the ORC, Mr Hadland said.