People

Acacia Water (from left to right: Goswin, John-Paul (not longer a member of the team), Jacob, Koos, Lieselotte, Albert, Jouke, Arjen. On the photo Theo and Monique are missing. They are members of the team since Januari 2012.

Arjen de Vries

General Manager

Arjen de Vries graduated in 1992 with a Master degree in soil science in Wageningen. After defending his PhD study in 1999, Arjen joined the international water resources department of Royal Haskoning, a Dutch consultancy firm in the field of water and environment. In this job, he acquired a broad experience in integrated water resources assessment and management and with the application of Remote Sensing and GIS techniques in (ground)water resources assessment and management. In 2004 Arjen became a member of the Acacia Institute. Since 2008, he is general manager of the Acacia Water, and carries out projects in the field of (ground) water resources, both in the Netherlands and abroad.
Arjen has a broad background, with special reference to institutional and awareness aspects of (ground) water projects. He is accustomed to complex projects, both in terms of institutional and technical aspects and often in the role as project leader.  His strengths are not so much specialist technical solutions, but in the arena of complex institutional settings finding appropriate solutions, both technical and institutional. Arjen utilizes both his technical background, and communicative and persuasion skills to carry out projects successfully. Through his involvement in many international projects, often under difficult circumstances, he has learned to approach problems and people in a creative, positive and optimistic manner, such that solutions and options can be found in which all or most stakeholders feel comfortable.

arjen.devries@acaciawater.com

mobile +31 (0) 6-10917175
office +31 (0)182-686424
fax +31 (0)182-686239

Albert Tuinhof

Senior Groundwater Management Advisor

In 1976, I graduated with a degree in civil engineering from the Delft University of Technology with a specialisation in groundwater hydrology. After a 3-year contract in a rural water supply project in Indonesia, I joined IWACO BV (now Royal Haskoning) in 1979 as a groundwater hydrologist and the team leader for water supply and groundwater management projects in the Netherlands, Mozambique and Egypt. In 1991, I returned to Rotterdam as regional manager for Egypt and the Middle East and since 1996 have been the manager of the international water resources business group.
Since 2002, I was strategic advisor for the water division in the new Royal Haskoning organisation. In these capacities I made frequent visits to the Middle East and other countries. In 2000, I became a member of the groundwater management advisory team of the World Bank (GWMATE), for which I conducted advisory missions to Pakistan, Cambodia, Kenya, Southern Africa (SADC), Nepal and Zambia.
 

In 2003 I founded the Acacia Institute together with Koos Groen. In my position at the Acacia Institute and currently Acacia Water I have continued the work for GWMATE. With regard to my professional affiliations, I am chairman of Netherlands National Committee of the International Association of Hydrogeologists and member of the Advisory Board for the Youth Water Action Team.

albert.tuinhof@acaciawater.com

mobile +31 (0) 6-10901840
direct +31 (0)182-686424

Koos Groen

Senior hydrogeologist

In 1980, I graduated with a degree in hydrogeology from the Institute of Earth Sciences at the Vrije Universiteit Amsterdam and joined IWACO BV (now Royal Haskoning). For 14 years I worked as a resident consultant in the Netherlands, Mozambique, Burkina Faso, Ghana, Pakistan and Suriname. I gained experience in water supply projects for cities, industries, rural communities and irrigation. Since 1988, the focus of my work has shifted to groundwater pollution, wetland restoration and integrated water management.
In 1994, I joined the Faculty of Earth and Life Sciences of the Vrije Universiteit Amsterdam. There I conducted a PhD study (2002) on the topic of freshening and salinization of coastal and offshore groundwater. In addition, I assisted MSc and PhD students. I was also a lecturer in applied geophysics, groundwater exploration, isotope hydrology, groundwater systems and groundwater management.
 

In 2003, I founded and started working at the Acacia Institute with Albert Tuinhof, with a part time assignment as lecturer in hydrogeology at the Faculty of Earth and Life Sciences and the UNESCO Institute for Hydraulic Engineering in Delft.  Acacia Institute was the predecessor of the current Acacia Water, of which I’m partially the owner.
In terms of professional affiliations, I am a member of the National Committee for IHP (UNESCO) & HWRP (WMO) and member of the JIIHP Steering Group (UNESCO/IAEA).

koos.groen@acaciawater.com

mobile +31 (0) 6-10909945
direct +31 (0)182-686489

Jouke Velstra

Senior hydrogeologist

In 1997 Jouke Velstra graduated with a Master degree in hydrogeology at the Faculty of Earth Sciences of the Vrije Universiteit Amsterdam and a Master degree in geology at the Faculty of Earth Sciences of the University Utrecht. In that same year he joined with Royal Haskoning, where he was project leader for the development of the integrated modelling environment TRIWACO and the training of staff members. Knowledge transfer and training of staff members of counterparts is an integral part of his job. He now has over 10 years of experience in hydro-geology and geochemistry, both in the Netherlands as abroad. His expertise covers all aspects of groundwater system analyses (isotopes, geophysics, structural hydrology, karst hydrology and geochemistry) and surface water – groundwater interaction whereby groundwater modelling and geo-chemical modelling are used as powerful tools. He joined Acacia in 2007 as a senior hydrogeologist and groundwater modelling expert. In 2008 he started with its PhD study at the Vrije Universiteit on the topic salinisation of coastal aquifers as a consequence of climate change, sea level rise and land subsidence and development measures. 

jouke.velstra@acaciawater.com

mobile +31 (0) 6-12133713
direct +31 (0)182-687117

Lieselotte Tolk

Hydrogeologist

Lieselotte Tolk graduated in 2005 with a Master degree from the Vrije Universiteit Amsterdam in Geo-Environmental Science, with a focus on climate change and eco-hydrology. After graduation she started working at the same university as a PhD-researcher. She developed a modeling system to quantify the CO2 uptake and emissions at country-scale, based on observations of the CO2 concentration in the atmosphere. For this she used atmospheric and biospheric models to simulate the transport of CO2 through the atmosphere and the CO2 exchange by the vegetation. In march 2010 she joined Acacia Water and started working as a geo-hydrologist. She works on projects in the fields of water quality, interaction of the groundwater with the vegetation and fresh water availability both in the current situation and under a changing climate.

lieselotte.tolk@acaciawater.com

mobiel +31 (0)6-10914315
direct +31 (0)182-686424

Theo Kleinendorst

Senior Hydrogeologist

Theo graduated in 1987 with a degree in hydrogeology from the Institute of Earth Sciences at the Vrije Universiteit in Amsterdam and joined IWACO BV as hydrogeologist and geophysicist for a number of water supply projects in West-Africa. Theo worked in the Netherlands and abroad (West Africa, Middle East, India, Suriname) in the field of water resources assessment and management where groundwater monitoring and data management are important aspects.

Theo has a broad experience in the following subjects: water resources assessment and management, software development, management information systems, GIS and remote sensing, groundwater modeling, geophysical prospecting and water wells. 

He uses his technical, specialist background to find creative, practical solutions for water management problems.

theo.kleinendorst@acaciawater.com

mobile phone +31 (0)6-
direct +31 (0)182-686424

Monique Teeuw-Scholsz

Office Manager

Monique is our office-manager. With her experience everything within Acacia goes smoothly.

Monique.Scholsz@acaciawater.com

mobiel +31 (0)6-83797000
direct +31 (0)182-686424

fax +31 (0)182-686239

Goswin van Staveren

Senior Geohydrologist

Goswin van Staveren graduated in 2001 from the University of Utrecht in the field of Geophysics. After his study Goswin started working for Royal Haskoning as a groundwater specialist. His duties consisted of providing groundwater consultancy by aid of complex model studies. 

In 2006 he joined Nelen & Schuurmans where he became project leader. His function at this point became more generalistic. Projects consisted of writing policy documents as well as providing a link between technical advice and the policy makers. In March 2009 Goswin joined the Acacia team where he is currently active as senior project manager.

goswin.vanstaveren@acaciawater.com

mobile +31 (0)6-13302072
direct +31 (0)182-686489

Jacob Oosterwijk

Geohydrologist
 
Jacob Oosterwijk studied from 2004 to 2010 at Wageningen University (WUR). After finishing his master Hydrology, with a minor ‘International Development Issues’, he started his work at Acacia Water.

For his master-thesis ‘Hydrological drought characteristics of the Nedožery sub catchment, Upper Nitra, Slovakia, based on HBV modelling’ Jacob went a few weeks to Bratislava. This master-thesis was done as part of the EU-WATCH programme (Water and Global Change). Jacob did his internship at Acacia Water. For his internship Jacob made a water and salt balance of the Schermer-polder.


jacob.oosterwijk@acaciawater.com

mobile +31 (0)6-12143599
direct +31 (0)182-687117

Tarun Ghawana

GIS specialist

Tarun Ghawana is our GIS specialist. He got his MSc GIS with the specialisation natural resource management from the International Institute of Geoinformation Science and Earth Observation (Netherlands).

He has executed assignments as a GIS expert in India, Netherlands, Germany and Kenya on natural resources management projects with academia as well as private consultancies. His area of expertise includes spatial analysis and spatial data modeling in particular for natural resource applications. His research work includes international publications focused on spatial dimensions of groundwater management.

Contact:

arjen.devries@acaciawater.com

direct +31 (0)182-686424

Acacia Water • Jan van Beaumontstraat 1 • 2805 RN Gouda • The Netherlands • Tel: +31 (0)182 - 686424 • Fax: +31 (0)182 - 686239