How to assess the impact of choices in water management on the shipping sector?

How to Assess the Impact of Choice in Water Management on the Shipping Sector Tuesday, September 9 1:45 pm - 2:00 pm CDT RM 104 Technical Session B1: Economics of Inland Navigation About Rivers and the water system, used for inland navigation, have also other functions. In case of water scarcity it might be necessary to take measures to replenish the water supply or limit salt intrusion. These measures will result in negative impacts on the shipping sector. Climate change and thus increased water scarcity will result in an increased frequency of the use of measures. This combination of factors form a thread for the functioning of the waterways and thereby transport system. Rijkswaterstaat is responsible for the different functions of the water system. They have the obligation to execute stress tests to examine if the network meets the European standards. Determining the effect of measures for one function on the shipping is part of this task. Deltares has developed a method building upon earlier work to assess the functioning of the waterway network when measures are taken for other functions. Earlier work looked at the effect of drought, bed level erosion and lock operation. The consequences of four effects of scarcity measures on the waterway network were investigated within the project. The most straightforward is the reduction of navigable depth due to an increased extraction or redirection of water from free flowing rivers. The second effect is the increased waiting time at locks due to a change in lock operation. Furthermore, at certain locations there can be limitations for navigation due to nautical safety issues that might result in sailing restrictions for specific types of vessels. Finally, the effect of lock operation restrictions on seagoing vessels has been assessed using measurements of a dry summer. The results showed the impact of measures on navigation that are taken during drought for other functions. This provided vital insights in some of the consequences for the water manager. In order to help decision making, a dashboard was made based on these outcomes to assess the effect of redirection of water on the inland navigation. In order to make a more quantitative assessment of the effect of measures two difficulties have to be resolved that may be picked up in future research. The first one focusses on the difference between sea going vessels and inland navigation. The consequences of limitations for inland or maritime navigation are different, but also connected. These transport flows are directly influencing each other. Secondly, it's not always possible to assess the impact of the measures on other functions quantitively. Both related to the uncertainty of the physical effect on the water system and the assessment of the consequences of too much salt on certain functions. Currently, it's not possible to objectively quantify the potentially irreversible consequences of salt water intrusion into vulnerable freshwater ecology areas.