Atazar, El reservoir

Madrid · Comunidad de Madrid

Tajo basin Reservoirs in Comunidad de Madrid

Province: Madrid
Basin: Tajo
River: Lozoya
Dam: Arch · 1972

65.7%

Current level

280 hm³

Stored water

426 hm³

Total capacity

-3.0 hm³

Weekly change

-53.0 hm³

Vs. 2025

-12.4 hm³

Vs. 10-year mean

Historical trend

Stored water volume · hm³

hm³

Weekly summary

The Atazar, El reservoir (embalse de Atazar, El), in the Tajo basin and linked to Patones y Atazar, Madrid and Comunidad de Madrid, is at 65.7% of its capacity, holding 280 hm³ against a maximum capacity of 426 hm³. It is currently falling, by 3.0 hm³ this week.

Compared with 2025: below (-12.4 points). Compared with the recent historical mean: below (-2.9 points).

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

References
Reference	Level	Difference
Previous week	66.4%	-0.7 pts
Same week 2025	78.2%	-12.4 pts
10-year mean	68.6%	-2.9 pts

Technical data

Characteristics of the dam and its recorded uses.

Characteristics

Municipality: Patones y Atazar
River: Lozoya
Dam type: Arch
Year built: 1972
Surface area: 1,070 ha
Upstream: El Villar
Downstream: Castrejón

Recorded uses

Water supply
Irrigation
Electricity
Industrial
Fishing
Boating

Not recorded: swimming, picnic, restaurants.

Source: MITECO Inventory of Dams and Reservoirs.

Data: MITECO · AEMET