No exceedances of the tested gas values were found at three monitoring points. The visible pollution remained in the Mrežnica and did not reach the Korana confluence—but clean-up and monitoring are continuing.
The latest position on 1 September
The City of Karlovac reports good air quality following measurements at three locations. None of the gases tested exceeded the occupational exposure limits or short-term values used for comparison. That is a reliable all-clear for the measured air conditions, but it is not a laboratory result for the water.
According to the city, the visible contamination remained along the right bank of the Mrežnica and did not reach its confluence with the Korana. Hrvatske vode contained its spread with booms; clean-up and monitoring continued. The new notice did not explicitly lift the swimming ban.
What now applies in Karlovac
The City of Karlovac has prohibited swimming in the Mrežnica and Korana downstream from Mala Švarča until further notice. The ban explicitly includes Foginovo city beach on the Korana.
Direction is crucial: the restriction covers the river sections below the fire site, not every body of water or the entire city. As of 12:25 p.m. on 1 September, the city had not published an all-clear.
Why the swimming ban was imposed
While the industrial fire in the Mala Švarča business zone was being extinguished, firefighting water entered the Mrežnica. The city then imposed a precautionary swimming ban on the downstream sections of the Mrežnica and Korana.
This distinction matters: the discharge of firefighting water has been officially confirmed. Laboratory analyses are still needed to establish which substances are present in the river and at what concentrations. The ban alone therefore does not prove any particular chemical reading.
Why Foginovo is also affected
The Mrežnica flows into the Korana in Karlovac. Foginovo lies on the Korana, downstream within this river system. The city names the well-known urban beach explicitly so that the word “downstream” leaves no room for a mistaken interpretation.
On 1 September, the city reported that the visible contamination had not yet reached the confluence with the Korana according to observations on site. That was not an all-clear: the swimming ban remained in force, and the water sample for the Korana/Foginovo area is being analysed separately.
When the first results are expected
The city expects the air analyses from three measuring points in Karlovac by 2 p.m. on 1 September. The result of the water sample from the Korana, at Foginovo city beach, is due by 2 September at the latest.
For the sample taken from the Mrežnica at the discharge point, the city gives a timeframe of about one week. Another sample is to be taken there after the clean-up, with roughly ten days allowed for that second result. These dates refer to different samples and must not be compressed into a single “water result”.
The clean-up is continuing
According to the city, remediation of the wastewater that travelled from the fire site towards the Mrežnica began on 31 August and continued on 1 September. Emergency crews and the responsible services are continuing to monitor the situation.
For visitors and residents, one simple rule still applies: only an explicit notice from the city or the competent health authority can lift the swimming ban. Clear-looking water, no noticeable smell or a single inconspicuous spot do not replace that approval.
What is known about the fire
Croatia’s fire service headquarters received a report at about 4:25 a.m. on 31 August of a fire at an industrial facility in Mala Švarča. Halls or warehouses belonging to Nova Chem and Gavranović were affected. According to the city, around 60 firefighters and 26 vehicles were deployed; earlier fire-service figures cited 55 personnel and 28 vehicles.
No injuries were reported. During the night into 1 September, firefighters maintained a watch because small pockets of embers and smoke were still present. The cause of the fire and the damage remain under investigation.
How to act sensibly
Do not swim in the closed river sections, and wait for the official all-clear before entering the water. Observe barriers and city notices on site; in an acute emergency, call 112.
The swimming ban does not imply a problem with tap water or a blanket prohibition covering every body of water in Karlovac. Anyone planning another use of the river should ask the responsible authority or local operator instead of extending a bathing notice to fishing, boating or drinking water.
Evidence
Sources & date
Sources support the facts. Planning notes and recommendations are Golden Beach editorial assessments.
- Poznati rezultati: Zrak u gradu dobar, onečišćenje iz Mrežnice nije stiglo do ušća u KoranuCity of Karlovac · 1 September 2026, 15:28air measurements, geographical containment, barriers and continuing clean-up
- Rezultati analiza zraka u Karlovcu bit će poznati danas; vatrogasci i noćas dežurali na požarištu na Maloj ŠvarčiCity of Karlovac · 1 September 2026continuing swimming ban, remediation, timetable for air and water analyses, and fire watch
- Zbog izlijevanja vode od gašenja požara u Mrežnicu zabranjeno kupanje na Mrežnici i KoraniCity of Karlovac · 31 August 2026order and geographical extent of the swimming ban, including Foginovo
- Vatrogasci i dalje na požarištu na Maloj ŠvarčiCity of Karlovac · 31 August 2026businesses affected, scale of the response, injuries and ongoing investigations
- Požar u industrijskom postrojenju na Maloj ŠvarčiCroatian Firefighting Association (HVZ) · 31 August 2026alarm time, initial response figures and precautionary advice to the public
