| Cuenca | Capacidad | Embalsada | Variacion | ||
| Tajo | 11009 | 5175 | (47.01%) | -114 | (-1.04%) |
| Guadiana | 8630 | 4090 | (47.39%) | -85 | (-0.98%) |
| Duero | 7463 | 5268 | (70.59%) | -122 | (-1.63%) |
| Ebro | 7403 | 6037 | (81.55%) | -139 | (-1.88%) |
| Guadalquivir | 7373 | 3667 | (49.74%) | -26 | (-0.35%) |
| Norte | 3655 | 2903 | (79.43%) | -56 | (-1.53%) |
| Júcar | 3346 | 1194 | (35.68%) | -22 | (-0.66%) |
| C. Atl. Andaluza | 1878 | 1005 | (53.51%) | -14 | (-0.75%) |
| Segura | 1129 | 379 | (33.57%) | -6 | (-0.53%) |
| C. Med. Andaluza | 1041 | 527 | (50.62%) | -9 | (-0.86%) |
| Cataluña Interna | 740 | 607 | (82.03%) | 2 | (0.27%) |
| Galicia Costa | 684 | 528 | (77.19%) | -3 | (-0.44%) |
| Pais Vasco Interna | 21 | 19 | (90.48%) | 0 | (0.00%) |
