On the Rhine, the water levels at the constriction near Kaub in Rhineland-Palatinate, which are important for shipping, have continued to drop.
According to the Federal Waterways and Shipping Administration (WSV), the fairway depth was only 1.54 meters on Friday morning.
The day before it was 1.59 meters.
According to the WSV, the depth of the fairway is lower than in Kaub between Bingen and Koblenz on any other section of the Middle and Lower Rhine.
It is decisive for how much freight barges can still load.
The Kaub level was 42 centimeters on Friday afternoon.
The water level does not show the level at the lowest point, since the zero point of the water level is not in the middle of the river and at the deepest point of the river.
This is 112 centimeters lower.
If this value is added to the water level, the result is the maximum water depth in the fairway at this measuring point.
Less cargo at low water levels
According to the authority, the water levels are at an exceptionally low level for this time of year.
For the next three to four days, water levels are expected to fall another four to six inches.
The forecasts pointed to a slight increase from the middle of next week, but this is not "significant".
Cargo and passenger ships in particular have been struggling with the low water for weeks.
The inland waterway skippers must pay attention to the draft of the ship when loading their cargo and observe a safe distance from the river bottom.
At low water levels, they can carry less cargo.
The Federal Institute for Hydrology has declared that up to a water level of around 30 to 35 centimeters at the Kaub level, shallow inland waterway vessels can still pass the Middle Rhine route.
Forecasts assume water levels in the direction of 30 centimeters by the beginning of next week.
Then shipping on the Rhine in this area would "tend to come to a standstill," it said.
Much shift to road and rail
This is because at some point transport by ship is no longer economical.
Due to the low water levels, the Rhine Water and Shipping Office has not imposed any restrictions on shipping.
The office explained until when a transport is nautically possible and economically viable, depends on many factors such as the characteristics of the respective ship or freight rates as well as the contractual regulations of the bargemen.
The President of the General Directorate for Waterways and Shipping, Hans-Heinrich Witte, told the Frankfurter Allgemeine Sunday newspaper that he expects ships to sail the Rhine continuously this year, despite the persistent drought.
When the water level is low, however, these could transport considerably less freight.
"That means: cargo space on ships is scarce." This also makes it difficult to transport coal and oil on the Rhine.
"Then a lot has to be done by road and rail."
According to the economist Stefan Kooths from the Kiel Institute for the World Economy, the economic consequences of the low water level in the Rhine are painful.
Calculations on the consequences of the low water in 2018 had shown that industrial production would fall by around one percent if the Kaub level fell below 78 centimeters for a period of 30 days.
At the peak, industrial production was down by around 1.5 percent.
For the year as a whole, the low water in 2018 is likely to have cost 0.4 percent of economic output.
"However, the situation at that time cannot be transferred one-to-one to today," explained the scientist.
The "height of fall" for industrial production was much greater at the time.