| Cuenca | Capacidad | Embalsada | Variacion | ||
| Tajo | 11012 | 5812 | (52.78%) | -219 | (-1.99%) |
| Guadiana | 9261 | 4952 | (53.47%) | -8 | (-0.09%) |
| Guadalquivir | 8118 | 4297 | (52.93%) | -41 | (-0.51%) |
| Ebro | 7642 | 5238 | (68.54%) | -97 | (-1.27%) |
| Duero | 7507 | 4314 | (57.46%) | -130 | (-1.73%) |
| Júcar | 3337 | 924 | (27.69%) | 4 | (0.12%) |
| Miño-Sil | 3030 | 1885 | (62.21%) | -94 | (-3.10%) |
| Guadalete-Barbate | 1651 | 1041 | (63.05%) | -5 | (-0.30%) |
| Med. Andaluza | 1174 | 643 | (54.77%) | -4 | (-0.34%) |
| Segura | 1140 | 251 | (22.02%) | -5 | (-0.44%) |
| Galicia Costa | 684 | 435 | (63.60%) | -19 | (-2.78%) |
| Cataluña Interna | 677 | 594 | (87.74%) | -3 | (-0.44%) |
| Cantabrico Occidental | 518 | 370 | (71.43%) | -9 | (-1.74%) |
| Tinto, Odiel y Piedras | 229 | 177 | (77.29%) | -7 | (-3.06%) |
| Cantabrico Oriental | 73 | 57 | (78.08%) | 0 | (0.00%) |
| Pais Vasco Interna | 21 | 16 | (76.19%) | 0 | (0.00%) |
