high water vs tidewater

high water

noun
  • The state of the tide when the water is at its highest. 

  • The highest stage of a river. 

  • The location of high tide on a coastal area. 

tidewater

noun
  • Water affected by the flow of the tide, especially tidal streams. 

  • The seaboard. 

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