Kōmanawa Solutions Ltd

“Everything should be made as simple as possible, but no simpler”

~Albert Einstein

At KSL we believe in finding solutions that are simple, but not too simple. So what do we mean by “too simple”? Let’s take groundwater allocation limit-setting as an example. A complex problem that could be tackled through numerical groundwater modelling of groundwater-surface water connectivity, aquatic ecology effects assessment, extensive community consultation and economic impact analysis: an expensive and time-consuming process.

The simple solution:

Allocate groundwater based on a fixed percentage of annual average rainfall recharge, e.g. 50%.

Simpler than possible?

Rainfall recharge during 2015 – 2017 period was more than 50% below average, in response to the 2016 El Niño event. Groundwater had been allocated based on 50% of long term average recharge and usage was well above average. The outcome? More than 75% of total aquifer recharge was extracted in some areas, leaving little water in the aquifer to support spring-fed stream flows and aquatic life. Some streams dried up with impacts on ecosystem health, shallow wells lost water and debate over irrigation water use raged in the media and negative views about the effects of farming on the environment came to the fore.

Reducing water usage in retrospect, after over-allocation has occurred, is extremely challenging and can require multi-generational rates of change.

Finding the right balance between complexity and simplicity is a key part of delivering great science to support sustainable management of our natural resources and thriving rural and urban communities. We’ll help you to find that balance.

Zeb Etheridge BSc MSc Founder and Principal Water Resource Scientist

Zeb Etheridge, Principal Water Resource Scientist and founder of Kōmanawa Solutions and Adjunct Senior Fellow at the University of Canterbury, has 25 years experience in water resource science and management, spanning contamination and water quality, surface water and groundwater resources, numerical modelling, groundwater source protection, managed aquifer recharge, ground-source energy systems, water supply engineering, climate change impact assessment and mine water management.

After graduating with Distinction in MSc Water Resources, his career path has encompassed contaminant risk analysis and mitigation for major hazard contamination sources, water resource impact assessments for invaluable  water resources such as the World Heritage Bath Hot Springs (UK), water management design to remedy mine discharge impacts, water supply design and optimisation for MOD bases across the UK and delivery of blue-ribbon groundwater science to support water quality management of the Christchurch city aquifer.

“My goal is to deliver excellent science to support the wise stewardship of our environment, for us and our children after us. I strongly believe in open and honest science communication to inform the increasingly challenging natural resource management decisions we are now facing. I’m passionate about working together, across the social, cultural and political spectrum, to forge a prosperous future and thriving natural environment. I combine a clear vision of the pathway to achieving successful project outcomes with dedication to on-time delivery and out-of-the box thinking, to help my clients, partners and employers achieve success.”

Matt Dumont né Hanson BA, MSc Computational Hydrogeologist Matt@komanawa.com

Matt Dumont has more than 8 years of experience in groundwater resource management, numerical modelling, quantitative analysis, and data science.  Matt graduated with honors from Whitman College with a BA in Chemistry-Geology and was granted a Fulbright Graduate Award to complete an MSc with distinction from the University of Canterbury. Matt went on to work with the University of Canterbury, Bodeker Scientific, and Environment Canterbury.

A keen programmer, Matt enjoys bringing the power, efficiency, and automation of scientific programming to solve complex resource management problems. He believes that with scientific programming and novel thinking we can add value, integrate uncertainty, and provide the guidance that is needed to solve ever more complex environmental challenges. When Matt isn’t writing code and running models he enjoys tramping, mountaineering, and all other things outdoors.

Jens Rekker BSc, PGDipSci Principal Hydrogeologist

Jens Rekker has 29 years of experience in groundwater, hydrology, modelling and water resource management. Jens graduated as a geologist from Otago University with a Post-Graduate Diploma in Science (Credit) focusing on the water sciences. He went on to work with Amsterdam Water, international engineering / environmental consultancies, Lincoln Agritech, private practice, and Otago Regional Council. Jens has been fortunate to be able to apply his expertise in a wide range of professional applications, including water supply assessment, contaminated sites, basin groundwater quality analysis, groundwater resource assessment, mine water management, hydro-geophysics, applied monitoring techniques, indigenous values, computer modelling, catchment hydrology and region-scale water policy development.

Jens operates best in developing quantitative conceptual models of complex hydrological systems with an emphasis on the groundwater dimension. He enjoys matching innovative techniques of analysis to real-world water management problems from their inception to final outcomes, such as providing technical evidence in hearings or court. He passionate about informal science education, using layperson language in explaining complex hydro-environmental processes and mentoring of the next generation of professionals where he can. When not in the office or field, Jens can be found in the hills hiking or tending tree crops and vegetables in the garden.

Evelyn Charlesworth BSc, MSc (MURR) Water Resource Scientist

Evelyn Charlesworth is a recently graduated water resource scientist. Having completed a Bachelor of Science in Environmental and Masters in Urban Resilience and Renewal, Evelyn has a keen understanding of the intersection between people and planet. Water resources is her greatest interest within environmental science, given its vitality to the world. Evelyn has interned at Watercare Services Ltd for two summers, gaining experience in field work, resource consenting, and data processing. She was also part of the biosolids reuse project that has been setup at Watercare.

Evelyn is passionate about effective science communication and integrating Indigenous knowledge and science to respond to the current climate crisis. She believes in working together to create a kinder, more environmentally-just world. Her education has spanned a variety of topics, allowing her to better understand the interconnected world we live in. She has some background in coding and is currently on a journey of learning Python! Evelyn enjoys reading, cooking, running, learning languages, and spending time in nature.

Patrick Durney BSc, PGDip, MSc (Water Resource Management) Computational Hydrogeologist

Patrick is an experienced hydrogeologist with a strong background in groundwater science and environmental research, holding a BSc in Geology, a Postgraduate Diploma in Engineering Geology, and a Master’s in Water Resource Management from the University of Canterbury. He is currently a Computational Hydrogeologist at Kōmanawa Solutions Limited, applying his knowledge in groundwater science to address modern hydrogeological challenges.

Before this, he was part of the Environmental Research Group at Lincoln Agritech Ltd from 2019 to 2024, focusing on unsaturated flow and transport modelling, integrated water resource modelling, and evaluating groundwater mounding effects from artificial recharge. His contributions supported significant projects like the Braided Rivers Programme and the Critical Pathways Programme, aimed at solving complex hydrological issues. In previous roles at DHI Water and Environment, and Environment Canterbury Regional Council, Patrick concentrated on the hydrogeology of the Canterbury Plains, contributing to regional water management strategies, including the establishment of groundwater allocation limits.

As a member of the New Zealand Hydrological Society and the International Association of Hydrogeologists since 2010, Patrick has engaged with the hydrological community, sharing his work through presentations at conferences and in technical reports. His professional contributions include lead authorship in several technical reports, involvement in projects such as the Hinds Managed Aquifer Recharge trial, and input into environmental policy development and major engineering projects, reflecting his dedication to sustainable water management.