culvert vs sewer

culvert

verb
  • To channel (a stream of water) through a culvert. 

noun
  • A channel crossing under a road or railway for the draining of water. 

sewer

verb
  • To provide (a place) with a system of sewers. 

noun
  • A pipe or system of pipes used to remove human waste and to provide drainage. 

  • One who sews. 

  • A small tortricid moth, the larva of which sews together the edges of a leaf using silk. 

  • A servant attending at a meal who is responsible for seating arrangements, serving dishes, etc. 

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