The sentence means as much as: "Well, we fear the next rainfalls, that partly still continue in the mountains, in the Alpes, and then, of course, the Danube could swell again. Yes, "anhalten" has different meanings. 1. as in the sentence above it means as much as to continue. "Der Regen hält an" means it keeps on raining and raining and raining. 2. it also means to stop...funny, never thought of it, same word for stop and continue... An example: "Der Bus muss an der Ampel anhalten". The bus has to stop at the traffic light. You can anhalten a taxi (hail a taxi) oder die Luft anhalten (hold your breath). 3. you can also "jemanden anhalten etwas zu tun"...urge somebody to do something. "Die Mutter muss ihren Sohn dazu anhalten, seine Hausarbeiten zu machen." The mother has to urge her son to do his homework. Hope that helps!