overtopverb
/ˌəʊ.vəˈtɒp//ˌoʊ.vɚˈtɑːp/[ T ] (of water) to rise to such a high level that it goes over the top or edges of something:
Floodwaters overtopped the levees that year.
[ I ] (of a river, lake, etc.) to have so much water that the water goes over the top or edges of it :
There are fears that the river will overtop.