Lindis low flow rules discussed

The Otago Regional Council today hosts the first of two public meetings to discuss the possibility of imposing minimum water flow restrictions on the Lindis River, a catchment it says is "seriously over-allocated".

The meeting, at the Tarras Community Hall from 1pm to 3pm, would focus on the social, cultural, economic and environmental values of the river, ORC policy and resource planning director Fraser McRae said this week.

If a minimum flow restriction is created, it will be defined in the ORC's water plan and relate to a specific monitoring site.

People with resource consent to take water will have to stop if flows drop below the minimum.

ORC water resource scientist Matt Dale will talk about the river and its ecology.

The views of residents would be discussed and taken back to the ORC for analysis.

A second workshop would be held later this year, Mr McRae said.

A 10-page discussion document about the Lindis catchment is available on www.orc.govt.nz

It states flows are generally high during spring but greatly reduced during summer.

Heavy abstraction occurs and the river is occasionally "dewatered".

Anecdotal evidence suggests the lower Lindis River naturally runs dry during extreme droughts, but this is difficult to verify due to "the relatively small amounts of flow and rainfall monitoring", the document says.

ORC monitoring in recent years shows there has been a consistent loss of water downstream of the Ardgour Rd flow recorder, which is downstream of any surface water abstraction.

Data showed that without abstraction the river would typically flow all the way to the confluence with the Clutha River.

There are 31 consented surface water takes and six consented groundwater takes.

The ORC says the catchment is "seriously over-allocated".

A dynamic management flow regime has been proposed, reflecting natural extreme low flows and providing for trout spawning habitat.

The proposed regime for October-April inclusive is. -A management flow of 0.75cumecs at Ardgour Rd.

When flows at Lindis Peak fall below 0.96cumecs, the management flow at Ardgour Rd will drop to 0.4cumecs.

The 0.4cumecs flow will remain in place until flows at Lindis Peak reach 1.6cumecs, after which is will return to 0.75cumecs.