For three decades, we have been passionate about numerical models and creating tools that reflect reality as accurately as possible. Our goal is to understand the processes occurring within the study area and based on this knowledge, to develop solutions that enable informed and data-driven decisions.

Our projects take us to a wide variety of regions in Switzerland and occasionally abroad. In close collaboration with municipalities, cantonal and federal authorities, engineering firms, and research institutions, we are committed to protecting and sustainably managing our water resources.

A look back – from the beginnings to today

After many years of research and consulting work at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich, Jürg Trösch and Uli Kuhlmann decided to go into self-employment in 1995 and founded TK CONSULT AG. With scientific expertise and the motivation to establish numerical modelling within the Swiss private sector, they started their company in rented office space in Oerlikon.

The first major contracts soon followed, including important Swiss groundwater models such as ‘Alpenrhein’, “Dünnerngäu” and ‘Thurauen’, as well as the first site modelling for Nagra. Following the floods at Whitsunday in 1999, the Thurauen project was our first project for which a large-scale 2D discharge model was developed – now standard in almost every river engineering project. International projects, such as the PEGASOS earthquake study, expanded the range of expertise. In parallel, another pillar of the business emerged in software development: inverse modelling was integrated into programmes such as SPRING and FLUX/FLORIS, resulting in long-standing partnerships.

Over the following decades, TK CONSULT developed into a recognised engineering firm for numerical simulations of groundwater, rivers and lakes. The portfolio expanded to include studies on large-scale thermal groundwater use as well as 3D modelling for hydraulic structures. In addition, numerous scientific publications were published.

TK CONSULT AG has been part of the HOLINGER Group since 2016 and continues to operate independently as a subsidiary. The founders Jürg Trösch and Uli Kuhlmann have taken well-deserved retirement and the management has changed hands. The legacy of the founders is now being carried on by long-standing employees such as Michael Ballmer and Michel Kuhlmann. They are passing on their comprehensive modeling expertise and enthusiasm for technical details to the younger generation in the team with great dedication.

This legacy also lives on in the form of significant projects. One notable example is a groundwater management system developed in cooperation between Water Supply Zurich (WVZ), ETH Zurich, and TK CONSULT. The prototype co-developed by Uli Kuhlmann evolved into a dynamic real-time forecasting system. Today, this system provides WVZ with daily recommendations for optimal artificial groundwater recharge.

Our commitment to developing innovative solutions and successfully realising complex water and environmental projects remains unchanged. Every project, no matter how big or small, is part of our company history.

Voices from the Team

We asked the team, including one of the company founders, a few questions:

What makes working at TK special for you?

"I am fascinated by the use of mathematics to describe processes in nature that are subject to clearly defined laws. In addition, our varied work brings us into contact with people from a wide range of disciplines, such as geology, environmental science, energy, and engineering firms. We also come into contact with construction companies, power plant operators, transport companies, and water suppliers, as well as authorities from all three levels. The exchange with these people contributes to an enormous broadening of horizons, which leads to a better understanding of the connections between planning, execution, and operation in general. Our modeling work is a small but important part of the implementation of projects." Michael Ballmer, Project Manager

"The diversity of perspectives, genders, and nationalities. Although we are an engineering firm in Switzerland, we do not only consist of men and of Swiss nationals. It is precisely this diversity that I value. In addition, everyone treats each other with respect and friendliness, both on a professional and personal level - that's what makes our team a genuine and great team." Dila Demiral, Project Engineer

Which project do you remember particularly well and why?

“The Wellenberg project was a defining chapter in our company's history. TK CONSULT was founded in July 1995 with a business plan that focused on model calculations for NAGRA regarding the planned deep geological repository site at Wellenberg in the canton of Nidwalden. But soon after the company’s launch, things took a different turn: the Nidwalden electorate rejected NAGRA's drilling application request. This meant that there was no longer any need for further modeling – and a significant portion of the expected revenue was out of the window. We had to quickly rethink our strategy and compensate for the loss with new orders. Another exciting project was the Thurauen project. Costs of over CHF 50 million were approved unanimously by the cantonal council and the project was implemented. I always enjoy hiking there and observing the development." Jürg Trösch, founder

“Projects that were implemented promptly following our modeling work remain particularly memorable because they allow us to compare the model forecast with reality. For example, we were able to contribute to a revitalization project in the Upper Engadine using groundwater modeling, which has now been completed. The measurements confirm our model forecast.” Michael Ballmer, Project Manager

“I particularly remember the WVZ project, which represented an exciting interface between research and application. By optimising the groundwater injection quantity and consistently taking customer requirements into account, we were able to develop a significantly better solution. This project demonstrated how important it is to combine scientific findings with practical needs.” Ning Li, Project Manager

How did you find your way to the company?

"I have always had a keen interest in mathematics, but studying pure mathematics seemed too theoretical to me. So I decided to study civil engineering at ETH Zurich. Towards the end of my studies, I delved deeper into topics such as hydraulic engineering and gained my first experience in groundwater modeling in a course. For my thesis, I chose the topic “Estimation of groundwater recharge in selected areas of Vorarlberg” because I found the subject very interesting. The question of groundwater recharge arose from TK CONSULT's modeling in the Alpine Rhine Valley and the company's connection to ETH. This is how I came into contact with the company, where I eventually started working in March 2007." Michael Ballmer, Project Manager

What motivates you to work in this field?

"Models are used in natural sciences to understand why a certain system behaves in the observed manner and to make predictions about how it will develop in the future. In hydrogeology, we often encounter groundwater flow systems in which complex boundary conditions occur and the parameters of the aquifer change significantly within a small area. Such situations quickly exceed the scope of analytical models, making numerical calculations indispensable. For me, numerical modeling is therefore a key tool in applied hydrogeology - and a field of work that I definitely wanted to pursue further." Marina Bolat, Project Engineer

"To work on diverse, exciting and challenging projects in the areas of surface water, groundwater and natural hazards. Numerical modelling and programming serve as tools to improve process understanding. The focus is on finding elegant and pragmatic solutions together as a team and with our customers." Michel Kuhlmann, Project Manager

Looking ahead

The coming years will be shaped by a multitude of challenges: longer heat waves, heavy rainfall events, flooding, rising lake and river water temperatures, and advancing glacier melt. Added to this are rising water demand, longer periods without groundwater recharge, increasing pressure on groundwater-dependent ecosystems, and pollution issues such as PFAS, nutrient inputs, and persistent pesticide residues. Last but not least, conflicts over the use of water resources will continue to grow in importance.

At the same time, new focus areas will emerge or existing ones will gain in relevance. These include, for example, the designation of contribution areas for drinking water wells, the use of medium and deep geothermal energy, a holistic view of the water cycle - including the interactions between groundwater and surface waters - and concepts such as “sponge city” for sustainable urban water planning. Optimizations to hydropower plants and technical developments such as real-time models, decision support systems, central databases, and improved data exchange options will also play an important role in the future.

Numerical modeling plays a role in the assessment of all of these issues. In the coming years, we will continue to develop innovative solutions together with our customers, maintain reliable partnerships, and help shape the future of water with enthusiasm.

Our heartfelt thanks go to all our customers and partners: Your trust, your constructive cooperation and the exciting challenges you have entrusted us with have made this success story possible. We look forward to continuing on this path with you in the future.

Your TK CONSULT Team