Danube waterway, navigable to 98,5% in the last 11 years with an average navigation blockage of only 5,5 days per year

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Over the last 11 years, inland navigation was prohibited on only a total of 61 days. This makes an annual average of 5,5 days, respectively 1,5% unavailability.

In 11 years only 2 events of ice formation and 18 days flooding

The reasons for the navigation blockage were 43 days due to ice formation while high waters were made accountable for the remaining 18 days. A remarkable fact is that between 1996 and 2006, only two blockages were issued due of ice formation: In January 1997 (25 days) and January/February 2006 (18 days). While the blockages due to high water occur more frequently, the consequent blockage periods are considerably shorter. The most important events were the floods in August 2002, in July/august 2005 and in April 2006. In spite of these incidents, the availability of the Danube to navigation remains at an average of about 360 days a year.

Beside ice formation and high water, low water periods are the main reason for the limited usability of the Danube waterway. In this case, cargo vessels, for instance, can sometimes be loaded only up to 25% of their capacity which in turn results in a perceptible rise of the transport costs. A statistical evaluation of the water levels of the reference water level gauge at Wildungsmauer, East of Vienna, performed between 1996 and 2006 has shown very variable results: in the four years 1999 to 2002, the fairway conditions were very favourable for navigation whereas, especially in 2003, conditions for navigation were very difficult due to an unusually long low water period lasting from August to November. Furthermore, 2005 and 2006 were both coined in their last quarter with a low water period which led to a reduced draught for the vessels and therefore affected the attractiveness of the transport mode inland vessel for the manufacturing industry. Yet, while over the long term monitoring period it was noticed that years with extreme low water periods are actually rare, more stable fairway conditions still have to be assured in order to cope with such eventualities.

In the future even more reliable

The main aspect of the National Action Plan Danube Navigation (NAP) is the improvement of the waterway infrastructure; through the implementation of the “Integrated River Engineering Project on the Danube to the East of Vienna”, better and more stable fairway conditions can be guaranteed during low water periods. Further important measures in the field of infrastructure apply to the optimization of the routine maintenance work of the fairway channel as well as to the minimization of the lock revision times performed by Verbund – Austrian Hydro Power AG (AHP).

Source: via donau