| Cuenca | Capacidad | Embalsada | Variacion | ||
| Tajo | 11012 | 5697 | (51.73%) | -33 | (-0.30%) |
| Guadiana | 8635 | 6601 | (76.44%) | -16 | (-0.19%) |
| Guadalquivir | 8280 | 6348 | (76.67%) | 8 | (0.10%) |
| Duero | 7520 | 3980 | (52.92%) | 0 | (0.00%) |
| Ebro | 7507 | 4085 | (54.42%) | 0 | (0.00%) |
| Norte | 3655 | 1962 | (53.68%) | -4 | (-0.11%) |
| Júcar | 3336 | 1761 | (52.79%) | 13 | (0.39%) |
| C. Atl. Andaluza | 1878 | 1484 | (79.02%) | -1 | (-0.05%) |
| C. Med. Andaluza | 1177 | 807 | (68.56%) | -1 | (-0.08%) |
| Segura | 1141 | 636 | (55.74%) | -2 | (-0.18%) |
| Cataluña Interna | 736 | 597 | (81.11%) | -3 | (-0.41%) |
| Galicia Costa | 684 | 373 | (54.53%) | -7 | (-1.02%) |
| Pais Vasco Interna | 21 | 19 | (90.48%) | 0 | (0.00%) |
