From Nisramont to Liège, the Ourthe is a navigable waterway under Annex 1.A of the Walloon Government order of 19 March 2009. The rules of the game are therefore mostly a matter of flow and temporary administrative decisions. For the framework common to Walloon rivers, see the navigation conditions.
- Official status
- Paddling prohibited
- Regulated stretch
- The Ourthe downstream from Barvaux's mobile dam up to Comblain-au-Pont
- Reference gauge
- Tabreux
- Permitted range
- 2.5 – 65.0 m³/s
- 72-hour average
- 5.0 m³/s
An open stretch from Nisramont to the Meuse
Navigation is allowed from the Nisramont weir, not included, to the confluence with the Meuse in Liège. It is permitted all year. The hours for the navigable stretch are:
- 16 March to 15 June: 9:30 a.m. to 7 p.m.;
- 16 June to 15 October: 9:30 a.m. to 8 p.m.;
- 16 October to 15 March: 9:30 a.m. to 5 p.m.
The two closure days linked to fishing opening days do not apply to this stretch.
Thresholds that rise with the river
| Section | Station | Minimum | Maximum |
|---|---|---|---|
| Nisramont to the Maboge bridge | Nisramont | 3 m³/s | 31 m³/s |
| Maboge to the Barvaux weir | Durbuy | 1.9 m³/s | 50 m³/s |
| Downstream of the Barvaux weir | Tabreux | 2.5 m³/s | 65 m³/s |
The highest ceiling of all open Walloon rivers, 65 m³/s, applies downstream of Barvaux. This is the section, measured at Tabreux, that the Ourthe water level page follows. The minimum is judged on the average of the last 72 hours.
When flow alone doesn’t settle it
Flow is not the only reason for a closure. Article 8 allows the minister to ban or limit navigation temporarily, for nature or river management reasons, even if the thresholds are met. The status block above shows the decision in force, with the reason when the SPW publishes one; a stretch may remain closed with no reason displayed.
The upstream branches
The Ourthe orientale, downstream of the rue Porte à l’Eau bridge in Houffalize, and the Ourthe occidentale, downstream of the Prelle bridge, fall under Annex 1.C: open only from 1 October to 15 March, with a ceiling of 8.8 m³/s at Houffalize and 6 m³/s at Amberloup, and no minimum. These are sporty stretches, outside the leisure trips.
Put-in and legal basis
Launching and landing are allowed only at designated areas, marked according to Annex 3; do not stop on a private bank. The thresholds are set by Annex 2, the daily status by Article 6. The order requires no equipment, but the authorities consider a life jacket essential for children under 12.