The persistent low water levels on the Danube are currently leading to significant restrictions in civilian shipping.
While cargo ships have to reduce their loading capacities and passenger ships on various sections of the route – such as in the Wachau region and east of Vienna – are temporarily suspending or adjusting their operations, the connection between Vienna and Bratislava remains open thanks to the Twin City Liner. The fast ferry is operated by Central Danube Region Marketing & Development GmbH, in which Wien Holding and Raiffeisenlandesbank NÖ-Wien have a stake.
The high-speed catamaran's operational capability at low water levels is due to its specific design. Even when fully loaded with up to 250 passengers, the vessel has a draft of less than one meter. This allows the catamaran to navigate the route in the main channel as well as via the Vienna Danube Canal. During the current summer season, the vessel operates three times daily in each direction. According to the company, low water levels have not resulted in any service disruptions since the start of the regular service in 2006.
The current hydrology of the Danube is posing broader problems for shipping in Lower Austria and adjacent sections. The waterway company via donau is reporting water levels at several gauge stations that are significantly below the multi-year average. In addition to restrictions on passenger ship traffic, excursion services and regional roll-on/roll-off ferries are also affected by reduced tonnage or service suspensions. The shift of freight transport to rail and road highlights the vulnerability of river logistics to extreme water levels.
Although the shallow-water catamaran is maintaining its scheduled service, industry observers point to operational challenges during prolonged periods of low water. Shallow water increases the risk of damage to the waterjet propulsion systems from stirred-up sediment or debris in the fairway. Furthermore, the operating model is heavily dependent on seasonal passenger traffic, meaning that fluctuations in revenue due to adverse weather conditions or unplanned repairs impact the ship's profitability.