| Water level (m) | Normal water level | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | |||||||
| Days | Water volume | Days | Water volume | Days | Water volume | Days | Water volume | Days | Water volume | Days | Water volume | Days | Water volume | ||
| (Ave) | (Ave) | (Ave) | (Ave) | (Ave) | (Ave) | (Ave) | |||||||||
| 3.5 | Overflow warning water level | 1 | 1517.0 | 0 | - | 0 | - | 0 | - | 0 | - | 0 | - | 0 | - |
| 3 | Flood fighting corps standby water level | 1 | 1014.8 | 0 | - | 0 | - | 0 | - | 0 | - | 0 | - | 0 | - |
| 2-3 |
| 1 | 560.5 | 1 | 690.1 | 0 | - | 1 | 566.4 | 0 | - | 1 | 488.5 | 0 | - |
| 1-2 |
| 8 | 379.5 | 1 | 363.5 | 0 | - | 0 | - | 0 | - | 1 | 226.3 | 0 | - |
| 0-1 |
| 131 | 25.9 | 72 | 10.6 | 167 | 13.1 | 76 | 12.9 | 154 | 18.8 | 114 | 22.6 | 103 | 17.4 |