Answer by  
                                                                                          LeheckaG (1826)
                                                            
                          
                          
                                                          First, bail out what overflow sewage/water you can.
 
 You can try vacuuming/plunging/snaking your pipes;
 follow the pipes looking for a clean-out-access-plug.
 
 Pulling/sucking clogs out of your pipes is more beneficial than trying to force them down further;
 the later can make your clogs worse, by blocking your pipes even more.