Public demand for evidence of what the Manuherikia River would look like under various minimum flows has prompted the Otago Regional Council to release a suite of photos this week.

The council has published 20 photos on its website, showing what the river looks like at flows ranging between 922 litres per second and 3780 litres per second.

The photos have been taken from the same viewpoint, the Little Valley Road Bridge, which is 580 downstream from the Alexandra campground.

There are two views upstream and downstream of the bridge. The photos were taken between 2013 and 2019.

The council is consulting on five minimum scenarios, increasing incrementally from 1200 litres per second to 3000 litres per second.

Not included in the scenarios is the status quo of 900 litres per second and 4000 litres per second, which the Central Otago Environmental Society has suggested would be best for river health.

The five flow scenarios are not popular and irrigators and farmers have demanded more evidence of what they look like.

Hundreds of people attended public meetings last week to raise concerns about the future of the district economy, businesses and employment prospects.

New freshwater regulations implemented in 2020 require regional councils to make river health and wellbeing the first priority, above the wellbeing of people and communities.

Minimum flows are designed to maintain environmental outcomes, such as ecosystem health, good swimming, and low risk of nuisance algae.

They must also support Maori iwi cultural values such as mahika kai (food collecting) and mana whenua (care for the land).

Regional council documents state stopping irrigation at 3000 litres per second would severely stress farm viability.

Stopping irrigation at 2000 litres per second would affect farm viability and land valuations, while stopping at 1200 litres per second would slightly improve ecosystem health, but nuisance algae would persist, and farm irrigation would be “OK but may experience a modest reduction”.