Meet the Miniflume: a new water control system

Meet the Miniflume, a new system we have developed to automatically and accurately control the abstraction of small volumes of irrigation water. The system is ideal, for example, to control water abstraction when filling a farm storage dam.

The Miniflume system comprises two major components: the measuring section and the control gate. Each is easily engineered into a typical open-race water channel, to measure and control the flow rate of the water passing through it. The system provides measurement and control of the flow of water in a water race, with a control range of up to 300 litres/second.

How does the Miniflume work?

A Neon Metering Module (NMM), measures the water level in a flume section and applies a mathematical equation to convert the water level to water flow rate.

The NMM compares the measured flow rate with the remotely programmable target, and incrementally opens or closes a motorised gate to let more or less water through, maintaining the flow rate close to its target.

The flow data are continuously recorded on the NMM and regularly pushed to a NIWA server where historical and real-time data can be viewed using a standard internet browser. Alarm values can be set for all data, and SMS messaging programmed to send text alarms to nominated user(s).

Commercialising the Miniflume

To be able to manufacture, install and support multiple systems, NIWA has invited collaboration from external manufacturers to commercialise the Minflume control systems. A commercial trial of a production prototype is being carried out at a site between Timaru and Pleasant Point.

A glimpse into the future

Miniflumes will significantly improve our ability to reliably manage water resources, matching demand with supply while meeting the requirements of the resource consent. Miniflumes are scalable and may be aggregated into networks grouped according to application or user type.

NIWA's Steve de Lima tests the Miniflume 300. [NIWA]
The Miniflume gate controller [Photos: Rod McKay]