Statistics

Statistics by country and year

Yearly summaries computed from the daily readings of every station: how many station-days were spent below the low-water level (LDC) or above the high-water level (HDC) — as a count and as a share of the station-days with thresholds. Useful for agriculture (irrigation seasons with low water) and navigation (days with restricted draught).

Agriculture: station-days below LDC mark the low-water periods when irrigation intakes and water availability are under pressure.
Navigation: days below LDC mean draught restrictions on that sector; days above HDC mean suspended traffic.

Daily data from 1879 to 6 November 2026

Download this tab’s data (CSV)

LDC: Low-water mark. The river stays above it on 94 of 100 ice-free days; below it, ships cannot sail fully loaded.
HDC: High-water mark. The river exceeds it on 1 day in 100; above it, navigation can be suspended.
Station-days: One station-day is one station measured for one day: 13 stations over 10 days make 130 station-days. It shows how widely and how long something lasted.

Irrigation season 2011: Bulgaria spent the longest below LDC, 13 % of days

Irrigation season (April–September)

Station-days below LDC in the irrigation season, by country and year, against the average of the other years; the longest uninterrupted spells below LDC.

10%14%

8%11%

11%13%

13%5%

2011Meanbelow LDC in season

Irrigation season (April–September) 2011
countries	station-days in season	below LDC in season	%	vs. average
Germany	1,647	163	10%	-4 pp
Austria	1,647	5	0%	-1 pp
Slovakia	545	2	0%	-3 pp
Hungary	3,476	9	0%	-2 pp
Croatia	915	3	0%	-1 pp
Serbia	2,196	170	8%	-3 pp
Romania	2,379	254	11%	-2 pp
Bulgaria	1,098	139	13%	+8 pp

Longest spells below LDC

Uninterrupted periods of at least 5 days below LDC, by station.

Longest spells below LDC
Station	countries	From	To	days
Veliko Gradište	Serbia	2011-10-28	2011-12-11	45
Oryahovo	Bulgaria	2011-11-10	2011-12-19	40
Ruse	Bulgaria	2011-11-11	2011-12-20	40
Silistra	Bulgaria	2011-11-12	2011-12-21	40
Svishtov	Bulgaria	2011-11-11	2011-12-19	39
Szob	Hungary	2011-11-02	2011-12-09	38
Tulcea	Romania	2011-09-11	2011-10-17	37
Dunaföldvár	Hungary	2011-11-04	2011-12-10	37
Novo Selo	Bulgaria	2011-11-09	2011-12-15	37
Lom	Bulgaria	2011-11-10	2011-12-16	37

The daily series uses the first reading of each day.