Low water levels could result in further restrictions being imposed on navigation on the river Rhine in the coming days, the German Federal Institute of Hydrology (BfG) has warned. “It’s within the realm of possibility,” the BfG’s Bastian Klein told dpa in the western city of Koblenz on Wednesday. Up to a water level of about 30 to 35 centimetres at the Kaub gauge, shallow-draft barges could still pass the Middle Rhine stretch, he said. “According to the forecasts, we are heading towards 30 centimetres by the beginning of next week at the Kaub gauge. Rhine navigation in this area is likely to …