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Role with a view

When it’s extremely dry or far too wet, Cantabrians take a keen interest in lake levels and river flow. For the hydrology team at Environment Canterbury, it is their daily bread and butter.

Measuring and monitoring the rivers and lakes 365 days a year gives Environment Canterbury live data that tells us what’s happening and helps model what’s likely to happen during floods and droughts, as well as inform sustainable management of water as a resource.

The hydrology team, part of the Surface Water group, has 13 people throughout Canterbury but one of the most visible jobs is that of a hydrological officer, who spend most of their time out in the environment.

And after a day out in the Mount Somers area with Senior Hydrologist Officer Owen Payne it is clear that this role requires someone with plenty of initiative to tackle the challenges thrown in their way.

A computer could never do this job

There’s no doubt that technology has made a big difference to hydrologists – especially with equipment and computer modelling - but the fixed digital water level gauges in our rivers and lakes all around Canterbury are not (yet) infallible. A human is still what’s needed to routinely inspect each site and carry out manual monitoring to assess what’s going on with the waterways. The team visit each monitoring site regularly – usually every month or two.

Owen explains: “We need to look at the context of the situation – rivers can change their course, like they did after the July floods, so the meter might need to be moved to a more relevant spot. In summer, the growth of weeds can raise water levels, so we really need to look at the bigger picture rather than just a number.”

Owen surveys the monitoring site (the fixed water level recorder is in the background) at North Ashburton

The information gathered by the hydrology team is crucial to many. It helps Environment Canterbury to sustainably manage the overall water resource that’s available for irrigation, environmental values and recreation. It provides important data for staff in planning, consenting, surface water quality and enforcement, as well as for external stakeholders, such as farmers, recreational users of rivers and science and conservation bodies.

Hydrological information also helps create essential rainfall runoff models and flood forecasting models – which are very important for flood warning systems for landowners and civil defence.

His 4WD driving skills are impressive

Making it safely to the 155 river and lake sites monitored around Canterbury is a big part of the job. Owen and his colleagues often travel in pairs and the vehicles are equipped with safety gear and radio transmitters. For the remote sites in the hill country this can mean off-roading through some tricky countryside.

“If there’s been a lot of wind or rain, I’ll check in with the landowner before heading out – a tree across a track could muck up the whole trip. This year, the ground has been sodden and we’ve seen lots of change to some of the tracks, with washouts and fords. We’ve all undertaken 4WD training and have a lot of experience as well to help calculate risk.”

The other road users are not always courteous but Owen is patient and careful not to worry the stock.

The main piece of kit for the Ecan hydrologists is a SonTek FlowTracker. It may look low-tech (like a sheep crook with EFTPOS) but it’s actually very clever and collects all measurements digitally for the hydrologists to download once back in the office. The FlowTracker (worth at least $17k each) is an acoustic doppler velocimeter and works by using ultrasonic sound waves which bounce off the particles in the water to help calculate the velocity, and therefore flow, of the water.

The meter alone doesn’t do the job though – Owen needs to plot a course across the river stopping at least 20 times to take depth and distance measurements as well. These together will give you the flow.

“It usually takes about 20 minutes but sometimes it can take up to an hour. We were up at Asbhurton SH1 the other week and it took about an hour as the river was so braided and took so long to get across.”

The team also have some special remote-controlled boats – definitely not toys – that they can use when the water is too deep to wade across. They only have a few of these, due to their significant cost, but they are already proving their worth in those tricky spots.

He needs proper wet weather gear (ie. not an umbrella)

Owen with his FlowTracker, about to measure the flow at the Ashburton North site.

If you’re a hydrologist you need to be confident in the water and be equipped with the right gear. This becomes apparent as Owen braces against the force of the Ashburton River as he painstakingly completes his river flow monitoring across its width at the North Ashburton site.

Owen wears a life jacket and GPS spot tracker and also relies on his partner to throw him a safety rope if he gets into trouble. He has also undertaken extensive water safety training.

Owen starts measuring with the Flowtracker across a straight tape measure path.

“I checked the fixed reading in the office earlier and it was 9 cumecs (cubic metres per second) but now it’s reading 11.9 cumecs,” he reports on making it safely back to the bank. “Around 10-12 cumecs is where it gets a bit tougher for us to do manually so we might use the boat instead.”

A chainsaw comes in useful

The often-steep paths down to monitoring sites are maintained by the hydrology team.

Trekking into the monitoring sites down steep banks has meant the hydrology team have had to build and maintain a network of steps and pathways over the past 50 years for their own access.

“We keep track of what condition the tracks are in and will bring a chainsaw or gear out to do some maintenance if we need to,” says Owen.

Also required for the job is some good old Kiwi ingenuity. “If a meter or gauge is not working or has a problem, we should be able to do a basic fix. There’s a lot of travel time going backwards and forwards so once we’re here we want to get things right if possible.”

His lunch spots are pretty awesome

The back of the truck overlooking the monitoring site called North Ashburton is the lunch venue.

A perk of the role is the time spent in Canterbury’s outdoors. That is big part of what has kept Owen enjoying the role over the past 15 years, since he started off as a graduate assistant in the Christchurch office.

“I love being in the outdoors and getting out of the office. I am in the truck a lot but make up for that with all the walking backwards and forwards once we can’t go any further by vehicle.”

Owen also enjoys the variety of interesting projects he has been a part of over the years.

“It’s great working closely with the science team and being able to support them with what they need. Group investigations like the MALF (Mean Annual Low Flow) investigation on the Rangitata were really fun – where about eight of us got dropped off by helicopter at remote spots in one day to take readings at the same time.”

Owen has also been working on the Hinds/Hekeao Managed Aquifer Recharge (MAR) Pilot Project, providing water data to help gauge its effectiveness in replenishing groundwater levels.

The North Ashburton is the lunch venue

No two monitoring stations are alike

No two monitoring stations are alike. They all have their quirks and were built at different times. Most have a locked cabin or box which contains the fixed water monitor gauge, log book and use radio transmitter, cell phone or satellite for communication. The latter come in useful during flood events, when hydrology staff are often out in the field, checking river levels in person and reporting any faults with meters.

Owen’s favourite monitoring sites are at alpine locations, such as North Rakaia and Macauley at Tekapo.

“Turtons Saddle at the top of the Rakaia really is my favourite spot in the whole world.”

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