Inundate

Definitions:

Princeton says:

(fill quickly beyond capacity; as with a liquid) "the basement was inundated after the storm"; "The images flooded his mind"
and
(fill or cover completely, usually with water)

Webster says:

1

: to cover with a flood : overflow

2

: overwhelm <was inundated with phone calls>

Pronunciation: In as in in, Un as in that same sound I can't figure out what common word it's in! Sounds enough like en though, as in then. Date as in... date. Rhymes with eight, freight, appreciate, great.

Webster audio

Synonyms: 

Princeton 1  flood,  swamp
               2  submerge