Submersible dirty water pump (Knotty Ash L12)

Does any member have a surplus Dirty Water Pump they wish too re-home , must be in working order , mine has finally failed , I need this type of device in order too drain garden fish pond of foul water prior to a clean and refill , if a member has such a thing will be most grateful to hear from you , thanks in anticipation. Scouser100 .