De or het waterstroming?

The correct Dutch article is:

de waterstroming

Rule Words ending in -ing: almost always de. See the rule

How to use waterstroming

the waterstromingde waterstroming
this waterstromingdeze waterstroming
that waterstromingdie waterstroming
our waterstromingonze waterstroming
your waterstromingjouw waterstroming
every waterstromingelke waterstroming
which waterstroming?welke waterstroming?
a big waterstroming / the big waterstromingeen grote waterstroming, de grote waterstroming

Dutch words ending in waterstroming

grondwaterstroming

In compound words, the last part decides the article. See the rule