| name | image | Average flow (m³/s) | basin (m²) | Height (m) | origin location | mouth location | Length (m) | latitude (°) | longitude (°) | canyon | Map |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Asón |  | 551,000,000 | 680 | Cantabrian sea | 44,000 | 43.2027361111 | -3.5849750000 | Map | |||
| Nalón (river) |  | 55 | 3,692,000,000 | 1,443 | Cantabrian sea | 138,000 | 43.5646076000 | -6.0767160000 | Map | ||
| Miera River |  | 295,000,000 | 1,280 | Castro Valnera | Cantabrian sea | 41,000 | 43.1711578400 | -3.6635806600 | Map | ||
| Río Besaya |  | 465,000,000 | 870 | Cantabrian sea | 47,000 | 43.3628000000 | -4.5744400000 | Map | |||
| Sella River (Bay of Biscay) |  | 43 | 1,284,000,000 | 1,100 | Picos de Europa | Cantabrian sea | 66,000 | 43.4672222200 | -5.0641666700 | Map |