One of their regular jobs is to monitor the Waituna Lagoon, southeast of Invercargill, when the lagoon's seawall is opened to the ocean.
But securing a consistent sample was tricky and involved staff balancing on the unstable lagoon edge and dipping a steel bucket attached to the end of a long pole.
That was until environmental technical officer Doug Keith came up with a brainwave - a modified water bottle attached to a line and flung into the water using a surfcasting rod.
He bought a sturdy off-the-shelf water bottle, drilled a hole in the end, fitted a simple non-return valve used by plumbers, added a top breather, sealed around the hole with duct tape and Bob's your uncle.
Actually, all the bottles have been called Bob because they float and bob about initially.
He said they do not last forever and already there has been a Sideshow Bob, a Bobby Sue, a Ricky Bobby and a Bob's Your Uncle.
The surfcasting rod was bought second hand for under $100. While some of his colleagues were keen fishermen and had used a surfcasting rod before, Mr Keith had not and had to learn the skill.
He said everyone was familiar with the technique now and could fling the bottle a useful 20m-30m into the lagoon.
Earlier this year, principal technical officer Karl Erikson took the bob bottle to a national conference for regional council environmental technical staff where it won the Charlie Thurgood award for innovation.
Mr Keith said he was pleased his invention had been recognised.
''It does the job and keeps staff safe, and that was the aim.''
- allison.rudd@alliedpress.co.nz
