| Cuenca | Capacidad | Embalsada | Variacion | ||
| Tajo | 11009 | 6279 | (57.04%) | -20 | (-0.18%) |
| Guadiana | 8292 | 4744 | (57.21%) | -22 | (-0.27%) |
| Duero | 7463 | 5096 | (68.28%) | 21 | (0.28%) |
| Ebro | 7413 | 5199 | (70.13%) | 59 | (0.80%) |
| Guadalquivir | 7313 | 3246 | (44.39%) | 10 | (0.14%) |
| Norte | 3655 | 2911 | (79.64%) | 46 | (1.26%) |
| Júcar | 3346 | 808 | (24.15%) | -2 | (-0.06%) |
| C. Atl. Andaluza | 2216 | 943 | (42.55%) | -8 | (-0.36%) |
| Segura | 1129 | 229 | (20.28%) | -2 | (-0.18%) |
| C. Med. Andaluza | 1041 | 320 | (30.74%) | 1 | (0.10%) |
| Cataluña Interna | 740 | 199 | (26.89%) | 24 | (3.24%) |
| Galicia Costa | 684 | 525 | (76.75%) | 1 | (0.15%) |
| Pais Vasco Interna | 21 | 20 | (95.24%) | 0 | (0.00%) |
