What a negative reading shows
A water-level reading gives the height of the water in centimetres relative to the local zero of a particular hydrological station. That zero is fixed for the station; it is not sea level. So “−120 cm” means that the water is 120 centimetres below that gauge’s zero, not that the riverbed or water surface is 120 centimetres below sea level. Compare the station name, date, daily change, and forecast—not isolated figures from different places.
Why low water became important
Low water affects different systems in different ways. Navigation depends on available depth on a particular reach, waterway restrictions, and permitted draught; barges may carry less cargo. Hydropower depends on inflow and plant operation. On 2 August, Energy Minister Dubravka Đedović Handanović was quoted by 021 as putting Đerdap 1 at 20% capacity, Đerdap 2 at 30%, with inflow at about 1,500 cubic metres per second.
Current status
After the emergency staff meeting on 3 August, Prime Minister Đuro Macut said the energy system was stable and no general measures were being imposed on residents; the appeal to use water and electricity rationally remains. The same day, the provincial emergency headquarters banned system users from drawing water from the Danube–Tisa–Danube network in the South Bačka, North Bačka and West Bačka districts. This is not a general household water-supply ban. Citing the ministry, 021 also reported four vessels aground near Bogojevo and Bezdan; their crews are safe. RHMZ’s station-by-station operational readings and forecast can change daily.
Pančevo: refinery operation and a possible scenario
On 2 August, Aleksandar Vučić said the Pančevo refinery might have to pause temporarily if the Danube kept falling; he said the river was still navigable but cargo had to be cut to 50%. This was a warning about a possible scenario, not a shutdown decision. The next day, N1 reported that the water level had not yet affected production and that the refinery was operating normally; it said savings measures were being applied in other processes. No operator or authority has announced a halt.
Why this matters beyond river transport
Shallow water can raise transport costs when fuel and raw materials cannot be moved by barges at normal loads. Lower output at Danube hydropower plants changes the electricity system’s balance, but does not by itself mean outages. For the refinery, the relevant question is not one gauge reading but safe crude deliveries and the operator’s official operating status.
What remains open
The open question is whether further falls in water level and inflow will change crude deliveries or refinery operations. Follow RHMZ data and official statements from NIS, the refinery operator, or authorities: the refinery is operating for now, while a temporary halt remains only a possible scenario.