Complex sentence: Flooding due to the partially obstructed river continued to occur upstream of the debris dam and, as a result, flood warnings are still being issued for the Stillaguamish one month after the March 2014 slide.
Split into simpler sentences: Flooding due to the partially obstructed river continued to occur upstream of the debris dam. As a result, flood warnings are still being issued for the Stillaguamish one month after the March 2014 slide.