the generation Noach lived in is called the generation of the flood. they were subsumed by water.
water represents wisdom (חכמה). it is undifferentiated, contains what is necessary for life. and without something to hold it, water expands to cover and destroy everything.
in contrast, the generation of mashiach will be aspects of the generation of the flood. it is said that the torah that comes forth during these times will be so bright as to make all torah from before it to appear dim.
the torah is written to contain all wisdom. the torah is often compared to water. Noach's generation received so much water as to destroy their world; we receive the torah as to give life to our world.
a difference between these different waters that were received is seen in how we refer to the water of the generation of the flood—מי נח, singular waters. this is in contrast to the torah, which is referred to as מים חיים—multiple waters.
destruction is limited. creating is unlimited.