7 reservoirs with a combined capacity of 229 hm³ · latest official reading: 1 September 2026
The Tinto, Odiel and Piedras demarcation is currently at 72.5 % of capacity, about normal for the time of year. The week-36 average across 36 years of records is 67.6 %, a difference of +4.9 points.
For context: a year ago it stood at 75.1 % and a month ago at 76.4 %. Against last week’s reading it is falling (−0.9 points).
Blue line: average monthly filling for the whole demarcation since 1990. The dot marks today’s reading, 72.5 % in September.
With 1,908 weeks of record since 1990, the average pattern of the Tinto, Odiel and Piedras demarcation is clear: it peaks in April at 82.5 % and bottoms out in October at 64.6 %. That 18-point range makes it a moderately seasonal demarcation.
The highest reading in the whole series is 101.6 %, on 3 February 1998, and the lowest 30.1 %, on 5 October 1993. Comparing today against those two extremes says more than the bare percentage: 50 %% is comfortable in a demarcation that rarely tops 60 %%, and worrying in one that usually reaches summer full.
By capacity it is the 14th demarcation of the 14 covered by the hydrological bulletin: its 229 hm³ account for 0.4 % of everything Spain can store in mainland reservoirs. Today it holds 166 hm³.
The 7 dams the hydrological bulletin tracks in the Tinto, Odiel and Piedras demarcation, sorted by capacity. Linked names have their own page with the full record.
| Reservoir | Capacity (hm³) | Volume (hm³) | Fill | Δ week | Use |
|---|---|---|---|---|---|
| Piedras | 60 | 41 | 68.3 % | −1.7 | Irrigation / supply |
| Sancho | 58 | 48 | 82.8 % | +0.0 | Irrigation / supply |
| Jarrama | 43 | 29 | 67.4 % | +0.0 | Irrigation / supply |
| Olivargas | 29 | 24 | 82.8 % | +0.0 | Irrigation / supply |
| Corumbel Bajo | 19 | 14 | 73.7 % | −5.3 | Irrigation / supply |
| Los Machos | 12 | 3 | 25.0 % | +0.0 | Irrigation / supply |
| Odiel | 8 | 7 | 87.5 % | +0.0 | Irrigation / supply |
The figures on this page come from the official MITECO reservoir archive, the same database behind Spain’s weekly hydrological bulletin. The bulletin covers every mainland reservoir above 5 hm³ of capacity and is published every Tuesday with Monday’s reading.
The latest reading here is from 1 September 2026, and the comparison series starts in 1990. Nothing is estimated, interpolated or forecast: the percentage is stored volume divided by the usable capacity the bulletin itself assigns to the dam. Historical averages are computed over the same calendar week in every previous year, the only fair comparison in a system with such marked seasonality.
National summary and reservoir search on Reservoirs of Spain.
