Ullivarri reservoir

Araba/Álava · Euskadi

Ebro basin Reservoirs in EuskadiHydroelectric

Province: Araba/Álava
Basin: Ebro
River: Zadorra
Dam: Buttress · 1957

60.3%

Current level

88 hm³

Stored water

146 hm³

Total capacity

-1.0 hm³

Weekly change

-8.0 hm³

Vs. 2025

-5.4 hm³

Vs. 10-year mean

Historical trend

Stored water volume · hm³

hm³

Weekly summary

The Ullivarri reservoir (embalse de Ullivarri), in the Ebro basin and linked to Arrazua-Ubarrundia, Araba/Álava and Euskadi, is at 60.3% of its capacity, holding 88 hm³ against a maximum capacity of 146 hm³. It is currently falling, by 1.0 hm³ this week.

Compared with 2025: below (-5.5 points). Compared with the recent historical mean: below (-3.7 points).

Its main uses include water supply, irrigation and hydroelectric power.

References
Reference	Level	Difference
Previous week	61.0%	-0.7 pts
Same week 2025	65.8%	-5.5 pts
10-year mean	64.0%	-3.7 pts

Technical data

Characteristics of the dam and its recorded uses.

Characteristics

Municipality: Arrazua-Ubarrundia
River: Zadorra
Dam type: Buttress
Year built: 1957
Surface area: 1,490 ha
Upstream: — no data
Downstream: Mequinenza

Recorded uses

Water supply
Irrigation
Electricity
Fishing
Boating
Swimming
Restaurants

Not recorded: industrial, picnic.

Source: MITECO Inventory of Dams and Reservoirs.

Data: MITECO · AEMET