| Cuenca | Capacidad | Embalsada | Variacion | ||
| Tajo | 11009 | 6689 | (60.76%) | 21 | (0.19%) |
| Guadiana | 8630 | 5955 | (69.00%) | 82 | (0.95%) |
| Guadalquivir | 8096 | 5926 | (73.20%) | 50 | (0.62%) |
| Duero | 7463 | 5688 | (76.22%) | -9 | (-0.12%) |
| Ebro | 7403 | 5545 | (74.90%) | -72 | (-0.97%) |
| Norte | 3663 | 2978 | (81.30%) | -57 | (-1.56%) |
| Júcar | 3345 | 1379 | (41.23%) | 19 | (0.57%) |
| C. Atl. Andaluza | 1878 | 1472 | (78.38%) | 15 | (0.80%) |
| Segura | 1129 | 470 | (41.63%) | 9 | (0.80%) |
| C. Med. Andaluza | 1041 | 733 | (70.41%) | 24 | (2.31%) |
| Cataluña Interna | 740 | 464 | (62.70%) | 1 | (0.14%) |
| Galicia Costa | 684 | 498 | (72.81%) | 4 | (0.58%) |
| Pais Vasco Interna | 21 | 20 | (95.24%) | 1 | (4.76%) |
