Plexus 5.0 - The revolutionary data-driven approach to complex water challenges

Plexus 5.0 - The revolutionary data-driven approach to complex water challenges

Storm surges, sea level rise, heavy rain events, drought; as climate change takes hold, all are taking an increasing toll on Aotearoa New Zealand’s vulnerable three waters infrastructure.

Pinpointing a network “problem child” has often been a complex, time-consuming – and at times impossible – exercise in analysing years of SCADA data using Excel.

Tonkin + Taylor’s (T+T) new cloud-based Plexus 5.0 suite of tools is an industry gamechanger, delivering a data-driven approach to resolving complex water engineering issues, while also allowing clients to accurately prioritise their emergency works and capital spending.

Put simply, Plexus 5.0 combines clients’ existing SCADA data with that gathered from low-cost, real-time sensors to analyse current issues, identify trends and build predictive models.

David Wyllie, T+T’s Technical Director – Digital Innovation, says Plexus 5.0 is a “big leap” away from the traditional model.

“In talking to our clients, we found there was a huge amount of data inside the SCADA systems. Let’s not look at water infrastructure in the way engineers used to look at it, let’s bring in some data science skills – not just a snippet; one week or two weeks’ worth of data, let’s take all of it.

“Let’s take all of the SCADA data and overlay it with all the tidal data and all of the rainfall data and see what it’s telling us. When you start looking at the whole lot, you can see the influence of the tide, you can see the influence of the rain, you can see the water that’s entering the system and you can see the water that’s leaving the system. That data can also be used to prove solutions that Councils put in place actually work.”

Nelson City Council Inflow and Infiltration Engineer, Bill Ewing, had identified a number of issues in his wastewater infrastructure. Salt water was getting into the network and, from time to time, heavy rainfall during storms was causing pump stations and treatment plants to struggle.

For Nelson’s residents, the flow-on effects could be unpleasant, including sewage gushing from manholes in the city’s roads and, in the worst case, sewage erupting from gully traps on private property. Needless to say, Bill was keen to accurately pinpoint the causes, their locations and develop sustainable, resilient solutions.

“T+T’s Plexus 5.0 helps us understand which parts of our network are the real ‘problem children’,” Bill explained. “We’ve commissioned a number of reports lately, including inflow and infiltration reports for our pump stations and a pump station resilience report which covers the whole of Nelson.

“I’ve also just commissioned another one for salt water infiltration to get an idea of the role salt water plays in the network. I want to get an idea of a large volume, a medium or a small volume, because it happens every day, twice a day. Unlike rain events, the tide is every day, all day – especially during spring tides, when we get quite a bit more in our network.”

By understanding the differences between rainfall and tidal impacts, Bill says, he can prioritise repairs and capital spending.

Historically, Bill admitted, the process of analysing pump station SCADA data was “a bit of a painful process”, often involving making assumptions and “just hoping you get it right”:

“You’re trying to direct your mains replacement programmes and repairs to reduce the effects. My aim is to try and measure the improvements we make – so if we replace a main or do some work on a catchment, we can actually say how much improvement we’ve had. David’s new ‘toy’ will actually help us to gauge that. We’ll get some idea of what value for money we get from doing repairs and working catchments. We can also identify exactly which catchments we should be concentrating on, because we can see the ones that are giving us the worst inflows. We’ve already been getting some very nice results of tidal inflows as well. It’s all heading in a good direction and it’s helping me to understand where we should be focusing our expenditure.”

Inflow and infiltration is, he said, a universal problem.

“Anything innovative in that space will be well received and from the results I can see for Nelson, I can see a great use for Plexus 5.0 throughout New Zealand.”