How low summer river levels harm Germany's economy
STORY: The unusually hot and dry weather has caused water levels to fall on the Rhine river
It's a critical supply route for products ranging from grains to chemicals and coal
Cargo ships have been either unable to sail, or forced to sail with a reduced load
Shippers say some are leaving with only a quarter of the regular freight
That means more ships are needed, and added freight costs means higher prices for customers
Economists say it could knock as much as half a percentage point off Germany's economic growth this year
Costs for chemicals companies are expected to rise, which could lead to production cuts
And coal power plants, used now as an alternative to Russian gas, also face supply shortages
