A Gigawatt near Topusko

The campus would sit south-west of Topusko, in a triangle between Pecka, Katinovac and Crni Potok. The 2021 census counted 165 residents across the three villages, just nine in Pecka.

According to HRT, investors had already bought about 1,500 hectares in the area. The announced data campus itself would cover 310 acres, about 125 hectares, with scope to expand to 450 acres, about 182 hectares. Some Croatian media reported the original figure as 310 hectares. A solar power plant, substation and battery system are also planned on Andabak’s land.

Very Andakak, the founding partner of the project, says they decided for Topusko because there they have a country where it is possible to achieve a project "that will not harm nature and the environment", and notes that Topusko is at the centre of the country. Accurate particles and layout of buildings are not published, so the campus and the purchased land on the map are only shown in the scale around the middle of the triangle.

At full operation the campus would use about 5 to 5.5 terawatt-hours of electricity a year. Zagreb uses about 3.2 TWh, while end customers across Croatia bought about 17.4 TWh the previous year.

The connection force of 1,000 megawatts is greater than the power of the Krško nuclear power plant, around 700 MW. The estimates of how much of this would be the share of Croatian consumption differ depending on what it is compared to: HRT points 20 to 30 percentage, IT analyst Marko Rakar around 40 percentage, and October interview with project manager Mario Gudel indicates slightly more than a quarter.

The figures on the money are even less solid. The announcement of "more than 50 billion euros" includes equipment that the tenants should have just installed; the campus investor estimates at 12 billion euros and in Wall Street Journal The initial amount from 13.5 billions of dollars is indicated. Compared to this, all direct foreign investments in Croatia from 1993. to 2025. amounted to 56.9 billion euros.

The closest 400 kV line is about 40 kilometres to the north, on the transmission ring around Zagreb. The Topusko area currently has only 35 and 110 kV lines. Pantheon is seeking four 400 kV connections.

According to the connection project, a new 400 kV train station should be built at Topusko and four water lengths of 280 to 300 km, each capacity of about 1.3 GW. Dalekovod, a member of the Končar group, values to 400 to 450 million euros, and with roads and optics the investor lists more than 500 million.

The Croatian transmission system operator (HOPS) in July accepted the optimal technical solution of the connection. According to the HOPS ten-year plan, similar infrastructure would otherwise only be built 2034. and in the real script and 2039., according to ICTbusiness.

On the October 29 panel, Project Manager Mario Gudelj said that the contract's signature is expected in November. Igor Šumonja from HOPS said that the investor would pay for the construction of four lines from 400 kV and connection costs. Until November 9 there is no public signature certificate. Panel Report

The routes have not been published. According to the project manager, much of the route is followed by Tumbri – Bihac, and part of the HOPS project Lika. "Four power lines are foreseen, although one would be sufficient to provide the necessary amount of electricity," Mario Gudelj said.

Almost all the electricity that computers use turns into heat. A one-gigawatt campus would have to shed heat as fast as it consumes electricity.

As it will cool down, it has not yet been decided. The project manager identifies two possibilities: water from its own wells, with consumption "as two golf courses per year", or electricity, with slightly less efficiency. Investors say that it will not use public water or water from rivers and streams, that they have wells at five locations and that the thermal sources of Topusko will not be compromised.

Green Action in November warned of the possible consequences of thermal and underground water pumping. Gudelj is November 9 for HRT repeated that the project will not endanger public water supply and that electricity will not be collected. These are investor claims; the impact on water should be determined by environmental assessment and the effect on electricity price is not confirmed.

With the announcement, consumption of about 100 per second, seasonally, most in summer was reported. Nacional weekly estimated that the data centre of one giant with cooling evaporation spends 3.8 up to 15 million litres of water daily. The Ministry of Environmental Protection and Green Transitions in a solution from September 10 warns that pumping could drain underground water and draining hot water into streams would harm life in them.

Waste heat could, according to the project team, be used to heat greenhouses or dry agricultural products; a specific analysis with the local community has been announced.

The developer projects 3,000 construction jobs and 1,500 permanent jobs, plus about 6,000 indirect jobs. The municipality of Topusko has 2,222 residents.

The figures changed already on the day of presentation: in the morning they talked about 5,000 to 6,000 direct and indirect jobs, in the evening about 3,000 during construction and 1,500 after it. Experts are skeptical. “Data centres do not employ people”, said Marko Rakar. Nacional says that industrial models for centres from one gigawatt anticipate 100 to 300 jobs and information security expert Lucian Caric at best 1000 to 1,500, mostly technical staff.

Commissioner Ivica Kuzmić expects the municipality's revenues to rise three to four times and to keep young people busy. Construction would require thousands of workers, and Profity warns that, due to chronic shortages of labour in construction, a large part would probably come from third countries.

The developer’s schedule puts the start of transmission-line construction in the fourth quarter of 2027 and the first computing capacity in early 2029. Changes to the land-use plan have yet to be adopted, and the project still requires environmental assessment and permits.

The Ministry of Environmental Protection and Green Transition of September 10 ordered Sisak-Moslavina County to conduct a major assessment of the acceptability of the ecological network within the 5. the change of the spatial plan, because it cannot exclude the impact on the 11 strictly protected areas in the area, including the Blatusha and Saseva and the Koran River with caves, even though they are locations outside them. The study must contain hydrogeological and thermal models and assess the joint impact of all operations.

Mayor Ivan Celjak October 8 has launched changes in the decision on strategic environmental impact assessment. The changes would separate the area outside the construction area of the village for the campus, move part of the county road Ž3228 and provide for a power station with power lines, solar power plants and battery tanks greater than 20 MW.

Gudelj expected October 29 to complete the county procedures by the end of February or the beginning of March 2027 It is an investor assessment without the confirmed date of adoption of the change plan.

According to the Sisak.info portal, this phase could take a year to two or maybe longer. If the campus remains in the plan, the procedure itself is followed by an environmental impact study with public debate, and permits. For long-range long-distance pipeline routes following a location permit are followed by privileges or service, with a fee.