Our people work on a variety of projects in their chosen portfolios and are supported and encouraged to acquire new skills and knowledge. The integration of knowledge and insight from the different disciplines is of value to our clients.

John Holmes / Rowena Hay / Chris Hartnady / Kornelius Riemann

Richard Wonnacot / Jody Frewin / Dylan Blake / Paul Lee / Alex Kuhudzai / David McGibbon / Greg Molzen / Eddie Wise / Hugo Marais / Sinawo Oscar Jack / Lunga Nolakana / Luke Towers / Marshall Fusa / Kristian Gerstner / Magen Munnik / Julie Anne Buchanan / Mlamli Vundla

John Holmes



> Present

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Rowena Hay

Managing Director

1992 – Present

Rowena graduated with an MSc in Geology from the University of Cape Town. She founded Umvoto in 1992. Before she started the business, she worked in the mining sector and nuclear waste disposal. She initiated the Umvoto Internship Programme in 2002. She has been recognized for scientific contribution and entrepreneurship.

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Chris Hartnady

Research & Technical Director

Chris continues to be an important and informed resource to the media, granting interviews ranging from Acid Mine Drainage to earthquakes and tsunamis. His vast scientific experience and love of teaching has played a critical role in the success of Umvoto.

Chris joined the company in 2000. He received his PhD in Geology from the University of Cape Town where he was Associate Professor in the Department of Geological Sciences. He is internationally recognized in the field of structural geology and tectonics with an emphasis on Southern and Central Africa.

He has applied this knowledge to fractured rock aquifers, hazard and risk assessment and disaster risk reduction studies, with particular reference to geohazards. His experience in geospatial data analysis and remote sensing applications includes the use of space-geodetic methods.

His ability to develop innovative applications of technologies has led to several advances in the field of drilling, hydrogeological monitoring and use of geoinformatics for hydrogeological modelling.

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Kornelius Riemann


2002 - Present

Kornelius joined the company in 2002 after he completed his PhD at the University of Free State. His focus is on integrated water resource planning, development and management. He is an experienced Project Manager.

He is involved in the development and implementation of strategies for adaptive groundwater management, and this comprises improved resource evaluation and monitoring to support sustainable resource management.

He is knowledgeable about implementing the National Water Act (1998) as well as supporting environmental legislation. He is a specialist with regard to groundwater regulatory protocols.

He has worked in the areas of pollution assessment, remediation planning and safety and health protection on contaminated sites as well as quality assurance systems. He heads Umvoto's Quality Management System which ensures the company’s products and services are maintained at the highest quality. In March 2011 Kornelius was elected chairman of the South African Geological Society’s Groundwater Division in the Western Cape.

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Richard Wonnacot

Geodetic Specialist & Associate

2013 – Present

Richard Wonnacott joined Umvoto in 2013 as a geodesy specialist and associate. Geodesy deals with the measurement and representation of the earth, including its gravitational field.

Richard spent much of his career with the Chief Directorate: National Geospatial information and Directorate of Survey Services.  His extensive expertise in geodetic surveying was gained on several major projects, such as the preparation, observation and computation of  primary triangulation control network projects covering South Africa and Namibia.  He managed the technical, financial and personnel matters of the Directorate of Control Surveys from 1993 to 2013 and initiated and project managed the implementation of the country-wide network of active GPS base stations (TrigNet).

Richard is a member of numerous national and international committees and bodies. These include being on the Governing Board of the International GNSS Service since 2006 and the Executive Committee of the International Association of Geodesy since 2007


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Jody Frewin


2016 – Present

Jody holds an MSc in geology plus a B. Ed. She previously worked for PetroSA for 19 years, following 15 years of teaching (10 years of earth science at tertiary level, and five years of science at secondary level).

She was a specialist modeller at PetroSA, introducing geo-modelling workflows into best practice – overseeing modelling work and integrated teams involved in modelling. She also developed and managed PetroSA’s structured geosciences and sub-surface disciplines’ Graduate in Training (GIT) programme.

Jody’s interest in education was maintained through involvement in the University of the Western Cape’s taught Master’s degree, coordinating PetroSA experts (including herself) to assist with specific courses and assisting postgraduate students locally and internationally. This interest expanded when she was appointed as the PetroSA board representative for the Upstream Training Trust (funded by oil and gas companies undertaking exploratory work in South Africa to promote science in South Africa.)

“I enjoy the enthusiasm and passion of working at Umvoto, and am looking forward to being more involved in the modelling of aquifers,” said Jody

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Dylan Blake

Senior Geologist

2007 – Present

Since joining Umvoto Africa in 2007, Dylan has become proficient in hydrogeological monitoring data collection/analysis, groundwater assessments, South African environmental/resource legislation and groundwater use licensing, and rotary/core drilling supervision/contract management.  He has significant experience in Table Mountain Group and Sandveld/Bredasdorp Group stratigraphic analysis (along with a generally extensive knowledge of the geology and hydrogeology of South Africa), and structural modelling and fractured rock reservoir estimates of the Peninsula and Skurweberg Formation aquifers.

Dylan has sited high-yielding boreholes in structurally complex regions of the Table Mountain and Bokkeveld Groups, and has undertaken numerous groundwater assessments for farms, towns, schools, solar facilities and municipalities across the Western and Eastern Cape, North West and Limpopo provinces. His knowledge of coastal zone dynamics, sedimentary formations, environments and processes along the South African coastline has introduced additional expertise to the company, and he has undertaken large-scale coastal hazard assessments for the City of Cape Town and Provincial Government of the Western Cape. He has also worked on various mineral exploration and disaster risk reduction projects and initiatives, and has a personal interest in the potential effects of shale gas exploitation on water resources.



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Paul Lee

Environmental Scientist / Climatologist

2012- Present

Paul Lee joined Umvoto in 2012 after he returned from an over-wintering as an Expedition Leader and Senior Meteorological Officer at the South African Base in Antarctica. He holds an Honours degree in Environmental and Geographical Science. He specialises in Climatology and is a Registered Environmental Practitioner holding a certified EAPSA certificate. His environmental portfolio mainly involves the mining sector in which he focuses specifically on Right and Permit applications, environmental audits and development of Mine Work Programs and Closure Quantum’s.  His environmental experience also extends to in field management of drill and mining sites in the capacity of Ecological Site Manager.

nbsp; His Honours degree and related post academic work was largely focused on data collection and monitoring of weather stations and he has constructed, commissioned and operated weather stations from the Antarctica to the planets hottest environment in the Danakil Depression of the Horn of Africa.  His experience in managing projects and running his own company has provided him with an excellent platform for consulting and project management.  Paul is the Umvoto front man on all public relations issues over a wide range of fields within his experience.

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Alex Kuhudzai

Senior GISc Technologist

Alex joined the company in 2008. Alex studied at Fort Hare and received his BSc (Honours) in Computer Science where he focused on Applied Remote Sensing and GIS. Alex was also part of the team that won the Department of Science and
Technology's National Innovation Competition in 2007. In addition to his GIS and IT duties, Alex assists with maintenance and development of databases and tender process support.

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David McGibbon

Trainee Geologist / Hydrogeologist

2014 – Present

David McGibbon, who joined Umvoto in 2014, has a BSc degree in Earth Science (majoring in geology and geochemistry), an Honours degree in Geology from Stellenbosch University and a Masters in Geology (majoring in structural geology) from the University of Cape Town. Since joining Umvoto David has gained significant experience in hydrogeological field monitoring, drilling and contract supervision, boreholes siting, environmental reporting, Carbon 14 sampling and groundwater assessments including pumping test analysis and sustainable yield determination for farms, schools, solar facilities and municipalities. Outside the office David likes to take part in distance running and cycling.

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Greg Molzen

Trainee Geologist / Hydrogeologist

2014 – Present

Greg Molzen, who joined Umvoto Africa in 2014 as a Contract Field Technician, has a B.Sc. (Hons) in Geology from UCT. This was funded by Inkaba yeAfrica (a joint research initiative of the German and South African earth science communities) and the National Research Foundation.

Greg’s thesis included two weeks of mid-year field work along the South African-Namibian border. Lab work involved electron-microprobe use, along with XRF analysis, to produce “The Gannakouriep mafic dyke swarm in the Sjambok-Seven Pillars area, Lower Orange River: Field distribution, geochemical and petrographic analysis”. His bursary enabled him to attend an Inkaba yeAfrica Geo-Future workshop in Potsdam, Germany.

Practical and hands-on, Greg has rebuilt cars as personal projects and worked as a film camera crane assistant and skydiving rig packer. He also assisted with the installation of equipment and re-wiring of a Cape to Rio racing yacht and travelled in Thailand, Cambodia, Vietnam and Laos for three months. He enjoys sports such as hiking, surfing, downhill skateboarding, wakeboarding and climbing.

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Eddie Wise

GIS Technician

2015 – Present

Trainee environmentalist Eddie Wise focuses on GIS and environmental consulting, and is gathering experience on topics ranging from map-making to water supply schemes. Having enjoyed an internship with Umvoto during the first half of 2014, Eddie took up a fulltime post in 2015 after completing his BSc Forestry studies at Stellenbosch University. When not at the office or in the field, Eddie enjoys hiking, fishing, squash, beach volleyball and running half-marathons.

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Hugo Marais



Hugo recently joined the Umvoto family, bringing with over 17 years of consulting experience, functioning as manager and lead modeler, providing technical direction in the fields of groundwater flow and solute transport modeling, dewatering and groundwater resource assessment for the mining, industrial and petrochemical industries. He managed several multi-disciplinary projects from green-fields to brown-fields, focusing primarily on hydrogeology, providing practical and effective operational water management solutions throughout the whole project life cycle.

Hugo’s professional experience was obtained on projects in developing countries and overseas, using a variety of simulation tools for the revision of salt and water balance models, to manage potential environmental liabilities and conducting various technical and legal audits and peer reviews.

“I am excited by the prospect to contribute and develop sustained and responsible operations, which appeals to my ideals to value engineer risks, improving environmental impacts and general enhancement of socio economic well-being”.

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Sinawo Oscar Jack

Trainee Geologist / Hydrogeologist

2012 – Present

Sinawo Oscar Jack joined Umvoto as an intern, but currently working as a Trainee Hrydrogeologist. Sinawo completed his BSc (Honours) in Geology at the University of Fort Hare, in South Africa. His main responsibilities are data processing and analysis, geological and hydrogeological tasks and field work, as well as draft reporting. He has gained experience in data processing and analysis, foundational knowledge of geology, hydrogeology and water quality as well as an understanding of the concept of the Groundwater Reserve. In addition, he has gained supplementary experience in groundwater monitoring fieldwork, geological/hydrogeological draft reporting and EIAs.

He is currently undertaking monitoring tasks in the Hermanus Wellfield and Stanford area; and desktop studies for smaller projects.

His most recent contribution has been in the Support to the Implementation and Maintenance of Reconciliation Strategies for Towns in the Southern Planning Region; and the WRC Water Governance of Groundwater and Surface Water in South Africa.

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Lunga Nolakana

Trainee Geologist & Hydrogeologist

2014 – Present​
Lunga joined Umvoto in 2014 as an intern after completing his M.Sc. in Petroleum Geology. Since joining Umvoto he has been working in numerous projects where he deals with construction and running of groundwater flow models. Involvement in all these projects has allowed him to gain insight into numeric modeling, among his recent contributions has been constructing and running the groundwater flow model for water resource estimation for a project in Ethiopia. He has also been involved in monitoring of various wellfields around the Western Cape.
Lunga is also an avid runner, whether it’s tackling the daunting trails or the tarmac he is always ready for the challenge.

One day he will be taking on the ultimate human race (the Comrades Ultramarathon), with the hope of getting the silver medal in the first time of asking, meanwhile his just watching it from the comfort of his couch and training hard.

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Luke Towers

Trainee Geologist/ Hydrogeologist

2015 – Present

Luke Towers, 28, started at Umvoto in 2015 as an intern while completing his MSc. (Hydrogeology). Lukethesis was based on work Umvoto did in the Danakil Depression of Ethiopia.

Luke enjoys the exposure to diverse subjects and disciplines related to the earth sciences and is particularly impressed by the rigour of science and research at Umvoto. Through a combination of field work, research and reporting Luke is developing the required skills to understand and better define complex natural systems.

As a former intern, he offers training and support to current interns with the aim of piquing curiosities while identifying and developing career related goals. "I love the fact that every day I learn something new".

Luke completed his BSc. Geology through the University of Stellenbosch and his Honours and Masters through the University of the Free State.

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Marshall Fusa

Trainee Hydrogeological Technician

2013 – Present  

Marshall Fusa completed his BSc degree in Applied Geology at the University of the Western Cape.  Marshall is currently involved in wellfield monitoring and data processing.

His main responsibilities include field collection of telemetry data and water samples and routine maintenance of field equipment such as water level loggers and weather stations.

Since joining Umvoto in 2013, Marshall has gained significant experience in groundwater exploration and has further developed his skills in deep borehole drilling supervision and core/chip logging in the Oudtshoorn area.

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Kristian Gerstner

Junior Environmentalist

2017 – Present

Kristian joined Umvoto in 2016 as a part-time intern whilst completing his M.Phil. in Climate Change and Sustainable Development (UCT). He joined Umvoto full-time in 2017 as a Junior Environmentalist. His work focuses mainly on environmental consulting, climate and weather analysis, and monitoring. His interests also extend into disaster risk management and climate change adaption.

Kristian also has two years’ experience in the field of risk management, having worked in the waste industry prior to beginning his master’s programme.      

Kristian’s thesis has focused on the nature of social networks, and the influence they hold over water management and climate change views and behaviours at a local municipal government level. His work has been largely explorative and he hopes it will encourage further research into the area.

Kristian is a passionate musician who enjoys performing part-time. A lover of the outdoors, his favourite activities include, surfing, hiking, trail running, climbing, and mountain-biking.

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Magen Munnik

Trainee Geologist/ Hydrogeologist

2016 – Present

Magen Munnik, 25, graduated with a BSc in Applied Geology and a Postgraduate Diploma in Integrated Water Resources Management (IWRM) at the University of the Western Cape. She is currently finishing off her Masters in IWRM focusing on wetlands and water quality.

Magen joined Umvoto Africa November 2016 as a Junior Intern. Since then, she has gained significant experience in public participation within the Environmental Impact Assessment process and groundwater field monitoring as she has been given the opportunity to work on various projects. Magen has also gained insight and skills in laws and legislation, hydrochemistry data analysis, quality control, report writing as well as personal development in her time at Umvoto. She has a special interest in wetlands and is keen on broadening her knowledge and experience.

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Julie Anne Buchanan

Trainee Geologist/ Hydrogeologist

May 2017 – Present

Julie Anne Buchanan is a BSc (Hons) Applied Geology Graduate, having studied Earth Science at Stellenbosch University (SU) over four years.

Julie has been an intern for a few months at Umvoto and joined the team as a Trainee Geologist/ Hydrogeologist as of August 2017. She is involved in the Hydrogeological Drilling Projects whereby she has created maps in the software QGIS, and been to the field on a monitoring round, she will also be involved in supervision of the drilling; She is learning what is involved in the process of siting boreholes for the abstraction of groundwater, using her knowledge in Geology. Julie has also been exposed to working with environmental data such as water levels and rainfall.

“I love the atmosphere around working at Umvoto.

Everyone is friendly and easily approachable. The work I believe is challenging yet particularly meaningful and rewarding”, said Julie.

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Mlamli Vundla

Junior GIS

2016 – Present

Originally from Eshowe in KZN, 28-year-old Mlamli Vundla moved to Cape Town in 2006 and has been completing the last four modules of a BA degree in Environmental Management through UNISA. Next, he plans to undertake an Honours degree in GIS.

Mlamli says that, since joining Umvoto in September, key learnings have included the importance of professionalism and optimal time management; how to capture data using ArcGIS and QGIS; and arranging and filing maps chronologically

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