Catchment: where does the water we drink come from
Hera draws water from various supply sources: surface water (streams, rivers, lakes), groundwater (mainly located in plains), and springs located in hills and mountains.
The source mix depends on natural water resources and facilities available in each area, as well as on water availability at different times of the year. Surface sources are more subject to quantitative variations over time due to a more direct correlation between precipitation and flow rates in watercourses, especially in the absence of works (i.e. reservoirs) that allow water accumulation in periods of abundant flows and their release in periods of scarcity.
| Aquifer | Surface water | Springs | Total | |
| Bologna area | 49.2% | 45.8% | 5.0% | 100% |
| Ferrara area | 41.8% | 58.2% | 0% | 100% |
| Forlì-Cesena area | 15.4% | 78.7% | 5.9% | 100% |
| Modena area | 84.5% | 1.6% | 13.9% | 100% |
| Padova area | 95.2% | 4.8% | 0% | 100% |
| Pesaro-Urbino area | 16.4% | 56.9% | 26.7% | 100% |
| Ravenna area | 6.4% | 93.6% | 0% | 100% |
| Rimini area | 46.5% | 47.9% | 5.6% | 100% |
| Trieste area | 82.8% | 0% | 17.2% | 100% |
| Total | 50.5% | 41.7% | 7.8% | 100% |
| Aquifer | Surface water | Springs | Total | |
| Bologna area | 87 | 11 | 472 | 570 |
| Ferrara area | 26 | 2 | 0 | 28 |
| Forlì-Cesena area | 57 | 9 | 137 | 203 |
| Modena area | 83 | 2 | 272 | 357 |
| Padova area | 45 | 3 | 0 | 48 |
| Pesaro-Urbino area | 180 | 10 | 330 | 520 |
| Ravenna area | 10 | 2 | 0 | 12 |
| Rimini area | 13 | 0 | 74 | 87 |
| Trieste area | 13 | 3 | 2 | 18 |
| Total | 621 | 51 | 1.288 | 1.960 |
