The Department of Hydrogeology and Engineering Geology (HGIG) performs tasks from the scientific branch of geological engineering at the scientific and professional levels. It is an applied part of the geological profession that belongs to the technical sciences.

In addition to the core activity of HGI-CGS, basic maps, researchers participate in numerous diverse projects - scientific and/or professional - financed by a wide variety of sources: national scientific, mainly the Croatian Science Foundation (HRZZ), European (Horizon2020, Interreg, etc.) and other international funds, through various institutions such as UNESCO, to numerous market, mainly national, funding sources: ministries, agencies, faculties, local administration, water supply companies, geotechnical designers and other clients from the public or private sector.

In the future, institutions of our type will increasingly be financed by working on competitive projects of various kinds. The HGIG department has a rich tradition of participating in EU projects, from several COST projects in the 1990s, through our first Interreg projects in the early 2000s, to the significant increase in projects of this type after 2010. The HGIG department’s benefit from projects of this type is excellent. Thus, valuable research equipment was obtained, and fieldwork and analytics were financed, which have, or will, significantly contribute to the work on fundamental projects and scientific work sensu stricto, i.e. writing scientific articles and the preparation of doctoral dissertations. In addition, researchers, mainly young engineers, are employed directly on such projects. In this way, they gain rich experience and contribute to the department with their work, and since they are paid directly for the projects, they do not strain the budget of the Ministry of Science.

In addition to basic projects, scientific and EU projects, the HGIG department is traditionally present in numerous market projects at the national level and occasionally outside the Republic of Croatia. These projects often have a shorter duration but sometimes lasting several years. Researchers, as far as their basic and scientific work allows, continuously receive and implement new projects of this type, and it is possible to conclude that there are about twenty of them active at any given time. Scientists and experts of the HGIG department systematically and continuously propose new international and national scientific and professional projects. All these projects provide essential data for work in the core business, scientific research, and dissertations.

The department's researchers are trained to carry out numerous research procedures and prepare reports and studies, so the following can be distinguished: reports on sanitary protection zones, hydrogeological and engineering geological zoning, parts of environmental impact studies related to geological engineering, foundations related to construction projects, among which stand out in particular extensive experience working on linear infrastructure facilities and hydroelectric power plants, geophysical researches, tracing underground flows, researching deep and shallow geothermal and hydrothermal resources, finding new and studying existing supplies of underground drinking water, or groundwater resources for irrigation (or any other purpose), researching water quality, hydrochemical and isotopic properties of water, geohazard research, landslide and other instability research, GIS projects, remote sensing with unmanned terrestrial or aerial equipment, and laboratory analyzes of various types. Since the two natural environments in which geologists work in Croatia are significantly different, namely the karst Dinarides and the Pannonian region, some researchers are more or less specialized in working in one of them.

In addition to the traditionally essential professions, hydrogeology and engineering geology, in recent times, geothermal and hydrothermal research, remote sensing, and applied geophysical research are increasingly being conducted at the department.

Regarding the publication of scientific works, the department, as a whole, and individual researchers of the HGIG department, are among the most referenced scientists in the scientific field of geological engineering in the Republic of Croatia. A significant step forward in the number and quality of published papers has been made in the last decade, and the trend of increasing the number of scientific papers continues and is continuously encouraged.

In the HGIG department, as a kind of subunit, two laboratories operate: hydrochemical and engineering geological:

The hydrochemical laboratory has existed since the mid-1990s of the last century and has continuously improved since its establishment. It is now able to determine numerous parameters important for hydrogeological expertise at a high level. It is fully incorporated into the daily work of researchers - hydrogeologists. The laboratory has equipment for in situ measurements: field probes with multiple indicators, sensors for continuous measurement of EC, T, pH, and oxygen directly in the field (the so-called data-loggers), and depth probes. Of the laboratory equipment, the ion chromatograph, spectrophotometer, and Picarro analyzer that determines the stable isotopes of deuterium and oxygen-18 (instrument purchased as part of the IPA Adriatic project Drinkadria), and the TN analyzer from the company HACH and the analyzer for total and dissolved organic and inorganic carbons (purchased in as part of HRZZ project TRANITAL). The hydrochemical laboratory shares some of the instruments with individual laboratories of other departments. The method of procuring laboratory equipment through EU or HRZZ projects is the central aspect for the future improvement of equipment.

Unlike the hydrochemical laboratory, the engineering geological laboratory is somewhat younger. In addition to the preparation of samples, various engineering, geological and geotechnical experiments are successfully performed. The laboratory has already successfully conducted numerous analyses embedded in the department’s core activity, scientific papers, and doctoral dissertations.