When Joe Gendall saw a job ad for a hydrologist role at Watercare, he knew it was the perfect role for him.

“I thought it was 100 per cent up my alley. I love the mix of field work and office work.”

He landed the role – his first as a hydrologist – and his first day on our team was two days before the first COVID-19 lockdown, which threw a spanner in the works.

He had to learn the office-based side of the role remotely, while a fellow hydrologist did the field work.

It was also the start of the Auckland drought, so it was a busy time.

“Within my first three years of the job, I saw a wide range of hydrological events, from drought to the Auckland Anniversary flooding and Cyclone Gabrielle.”

Now a senior hydrologist, a large part of his job is managing and maintaining our hydrometric network, which has 66 sites across Auckland – rain gauges, dam level monitoring equipment, ground water monitoring and stream flow monitoring sites.

Our network tracks the volume of water at each stage of the water’s journey and the data from the rain gauges feeds into the source management model run by our Water Resources team.

The model helps us to balance our water sources and determine how much water we take from each of our sources in any given week.

“The data is also used to make sure we are compliant with our consents. We’re responsible for data processing and archiving and we often get data requests. If you wanted to know how much it rained on any particular day, I can tell you that.”

He can also keep an eye on most of the gauges and sites on his laptop, through our telemetry system.

“My role is half field work and half office work. I go out to sites for regular inspections to make sure our sites are kept in accordance with the National Environmental Monitoring Standards. These set out requirements and methodologies to enable consistent collection, processing and archiving of monitoring data."

“I’m lucky that I get to visit so many of our sites, like treatment plants and the headworks and dams. I go just about everywhere.”

Joe and his team liaise with NIWA and the MetService to arrange long-range weather briefings for the rest of the company, and they distribute weather event forecasts from Metservice for anything that could be impactful for us – things like flooding, high winds, and lightning risks.

Joe originally studied geology and geophysics at Auckland University and after graduating, he moved to Australia to work as an exploration geologist for a gold mining exploration company.

He later did a master’s programme at Freie Universitӓt in Berlin, studying environmental earth science, which included more hydrology-focused papers.

“It took my water understanding from below ground to the surface.”

Being a hydrologist lets him put that knowledge to good use.

“It’s quite a multifaceted role. I deal with a lot of people from across Watercare. It’s great to meet people from different teams, from communications to operations and planning. No two days are the same. Beyond our regular work, there are always projects we’re setting up or helping out with."

“One of my favourite things about my job is my team – I have great workmates!”

He’s also made a splash in the industry at large – he invented a new technique for assessing the accuracy of rain gauges, which was adopted by other hydrologists in New Zealand and Australia.

Joe presented his solution at the Australian Hydrographers Association conference last year, and it was discussed again at the 2024 New Zealand Hydrological Society Technical Workshop held in Queenstown in April.

"How much rainfall a rain gauge is going to record is affected by a range of things – including topography, elevation, exposure (such as high wind), and whether there are any obstructions," says Joe.

"All of those things need to be taken into account, because they have an impact on the air flow, which in turn affects rainfall recorded at the site."

Joe's solution uses a 3D camera, combined with some basic programming, to capture changes in obstructions – like vegetation growing near the rain gauges.

On the back of his presentation, he was asked to moderate a panel discussion called Beyond H20: A Discussion on Diversity at the Australian Hydrographers Association Conference in Australia.

“It was nerve-wracking. I’ve never done anything like that before. It was the first time they had had a diversity discussion at the conference. I started reading up on moderating and had some online meetings with the three panellists to come up with discussion topics. We came up with some questions that I would ask them to get the ball rolling.”

It turned out to be a positive experience with a lot of audience engagement.

When he’s off the clock, Joe spends a lot of time outdoors doing activities like rock climbing, trail running and surfing.

“It gives me time to relax and think. If something has stumped me at work, I’ll have time to think about it when I’m out and about.”