“Navigation is necessary” (Navigare necesse est), we quote often the old romans, mostly to support all plans for navigation developments. But the original statement was longer, it was “Navigare necesse est, vivere non est necesse” (Navigation is necessary, living is not necessary). The sentence is supposed to be said by Pompeius to his sailors when they had to transport grain from Sicily to Rome in the stormy see.

It is a wildly distributed opinion that navigation is environment friendly, kind of green. Many do not even doubt its reality, however data shows the opposite. But then, why is navigation necessary?

“Because the water is already there, we only have to sail it.”

One of the great advantages of inland navigation is that there is no need for any construction here, as "water is there already, we only have to sail it.” The facts of recent years seem to contradict this.

In 2018, River Danube showed the lowest ever level of water, which it held for months - virtually completely impossible for navigation.

Walkers in the middle of riverbed at Budapest, autumn of 2018. Foto: MTI- Balogh Zoltán http://www.ovf.hu/hu/hirek-ovf/sajtokozlemeny-181016

An actual policy paper worded that “recently the number of navigable days went under 250 days a year.” But how about the future? The Strategy on Adaption on Climate Change of the ICPDR (International Commission for the Protection of the Danube River) in 2013 (page 14) stated that („The tendency for drier summers strengthens during the course of the century…”

Change of summer mean precipitation in the Danube River Basin for different periods according to A1B and A2 scenarios of different model results. Green colour shows no change, grey shows contradictory data, blue the increase of precipitation, all other colours show decrease of precipitation.Resource: Strategy on Adaption on Climate Change, ICPDR 2013 https://www.icpdr.org/flowpaper/app/#page=14

Dredging of the riverbed may give answers for the low level water discharge. Still, it is only a temporary solution and is definitely found demanding. And, dredging of the riverbed may decrease the level of water table of the whole area. This correlation is stated among others by the report of the European Environmental Agency titled Groundwater quality and quantity in Europe: „Changes in river flow characteristics, such as surface water abstractions, river channelization and dredging of river channels for various purposes, may lead to decreasing groundwater recharge.”

In this relation is the disposal of the Hungarian National Climate Change Strategy (Nemzeti Éghajlatváltozási Stratégia), which emphasizes the avoidance of any action that may lower the level of water table (Chapter IV. 7.2. Water Management): “In the management of watercourses affecting groundwater levels, it is important to prioritize solutions that avoid deepen the channels and riverbeds so as to avoid lowering the water table” („A talajvíz szintjét befolyásoló vízfolyások kezelése során fontos a medermélyítés (csatornák) és medermélyülés (folyók) talajvízszint-csökkentő hatását elkerülő megoldások előnyben részesítése”).

Mr Georg Frank, Secretary-General of the DANUBEparksConnected Project, said in his presentation at the Danube Commission (Budapest) on September 11, 2019 that a recent survey conducted by conservation experts in the DANUBEparksConnected Project found that the factor that endangers riverine natural habitats the most was caused by the navigation and the maintenance of its infrastructure. In the same time Frank Georg also emphasized that this seems to be in conflict with the fact that 15% of conservationists never and 67% rarely have joint discussions with hydrographers and/ or navigation specialists.

Source: presentation of Frank Georg on 11. September 2019 (https://www.danubecommission.org/uploads/doc/2019/Joint_Statement_20190911_12/presentations/Georg_Frank_190911_DANUBEparksCONNECTED.pdf )

Source: presentation of Frank Georg on 11. September 2019. (https://www.danubecommission.org/uploads/doc/2019/Joint_Statement_20190911_12/presentations/Georg_Frank_190911_DANUBEparksCONNECTED.pdf )

In December 2007/ January 2008 the ICPDR (International Commission for the Protection of the Danube River), the Danube Commission and the International Sava River Basin Commission adopted a Joint Statement (https://www.icpdr.org/flowpaper/app/services/view.php?doc=Joint_Statement_FINAL.pdf&format=pdf&page={page}&subfolder=default/files/), which among others states: “on the one hand riverbed stabilisation works and dredging can eliminate ecologically important in-stream structures and lead to a uniform aquatic environment; whilst, riverbed erosion downstream of stabilisation works can lead to a vertical separation and hydrological decoupling of the river from its floodplain habitats.

In addition to hydromorphological impacts, navigation can also have other impacts on the water environment, such as pollution, which will be addressed in the respective EU WFD river basin management plans and in specific projects (e.g. on waste and sewage collection).

From the mechanical point of view, ship traffic causes waves, which can disturb the reproduction habitats of fish, benthic invertebrates, other biota as well as de-root aquatic plants. Ship engines can also cause an unnatural suspension of fine sediments, leading to reduced light for plant and algae growth…

…In order to guarantee an interdisciplinary approach and broader acceptance of the ongoing and future planning process from the beginning, the ministries responsible for environment, water management and transport, scientists and experts in river engineering, navigation, ecology, spatial planning, tourism and economics as well as representatives of other stakeholders, such as environmental non-governmental organisations and relevant private sector representatives, should be involved.”

„Because navigation is environment friendly and green”

The belief that navigation is environment friendly and green is widely spread. But data show something else. Inland navigation emits one and the half / double CO2 than railway transport.

Greenhouse gas emission in transport: CO2, CH4 és N2O emission in case of truck, train and ship in g/ tkm, in CO2 equivalent (Source: Umwelt Bundesamt, Emissiondaten, 2018. https://www.umweltbundesamt.de/themen/verkehr-laerm/emissionsdaten#textpart-1 )

CO2 emission in transport in case of freight train, passenger train, freight barge, truck, passenger car and airplane, in g/ tkm (or in G/ pkm) Resource: Rail Transport and Environment – Fact & Figures http://www.cer.be/sites/default/files/publication/Facts%20and%20figures%202014.pdf


„Because navigation boosts local economy”

Admiring the cursing ships on the Danube one may come to the idea that this from of tourism boots local economy. But scientific researches show something else.

Dr. Michael Meschik (University of Natural Resources and Life Sciences, Vienna), in a presentation in Budapest in 2018, stressed the importance of counting cycling tourists. He said the number of biker tourists in Austria is increasing year by year. The numbers show that although the number of longer ride bikers seems to have stopped, it is well offset by the number of daily hikers and daily cyclists. Surveys for 2018 show that on average one-day cycling tourists spend € 42, while multi-day cycling tourists spend an average of € 75 per day. Comparing the data of a similar survey from 2000 we see a significant growth of the sector. Further information: (https://eionet.kormany.hu/ecovelotour-konferencia ) and (https://eionet.kormany.hu/eurovelo-es-okoturizmus-fejlesztesek-ausztriaban )

In parallel, a survey on the daily spending of hotel boat passengers has been conducted by the Belgrade Tourist Organization of Belgrade. According to Danube Competence Center, Boris Čamernik, the average hotel cruise tourist spends € 6 a day on the spot. Further information: (https://eionet.kormany.hu/ecovelotour-konferencia )

At the same conference, Mr Máriusz Révész, Government Commissioner of „Active Hungary” said in a speech that "there is more money in Europe from cycling than from boat tourism." You can read more about it here (https://eionet.kormany.hu/ecovelotour-konferencia ) .


In a speech by Mr András Weiperth (Danube Ecological Corridor, Budapest, March 28, 2018 https://eionet.kormany.hu/danube-ecological-corridor ) stated that the Danube, which provides drinking water to approximately 23 million people, connects 5 geographical areas (Alps, Continental, Steppe, Black Sea and Pannonian) results in an extremely rich ecosystem. As a result of river regulation, navigation conditions improved, but the rate of wetlands in the Carpathian Basin decreased from 24% to 2%. However, he stressed that the transport corridors required by the EU could also be provided by rail, which, at least in an area where the rail network is extremely dense, should at least be considered.

Railway network of Hungary

Further information:

Handbook on the external costs of transport. European Commission, Version 2019 https://ec.europa.eu/transport/sites/transport/files/studies/internalisation-handbook-isbn-978-92-79-96917-1.pdf

Original of this article (in Hungarian language, 8th of October, 2019): https://eionet.kormany.hu/akadalymentes/hajozni-muszaj