outfall vs welling

outfall

noun
  • The point or place of discharge of a river, drain, culvert, sewer, etc.; mouth; embouchure. 

  • A quarrel; a falling out. 

welling

noun
  • The act of something that wells, or issues forth like water. 

How often have the words outfall and welling occurred in a corpus of books? (source: Google Ngram Viewer )