Rhine River water levels are expected to continue to decline on Monday, further restricting the supply of vital commodities to parts of inland Europe. The water level at Kaub — a key waypoint west of Frankfurt — is expected to drop to 30 centimeters (12 inches), according to German government data. The Rhine River fell below 40 centimeters to a new low on Friday as the continent battles with its worst energy crisis in decades. At that depth, it’s not economical for a lot of barges to transit the chokepoint.