Nice argument, but it has absolutely nothing to do with global warming. Lets have a look at the facts:
1) The snow in the alps melts every year. All of it. All of it that matters for us anyway, since most of the glaciers are positioned SOUTH of the watershed line, and the water from these glaciers will never reach the Netherlands. This means there is no "extra" melting done every year, because of shrinking glaciers or everlasting snow melting off.
2) This means that the amount of water melting in spring does not increase (and should actually DECREASE if you believe global warming, since more warming means less snow during winter, right?)
3) More and more of our rivers are being channeled up the line, decreasing the number of natural overflow basins up the line and therefore the Netherlands will get more water in less time during spring.
The influx of melting water in the Netherlands therefore has nothing to do with global warming, but has everything to do with water management projects in the countries up the line and the Netherlands itself.
Can't speak for rising sea levels, but when it comes to melting water, the Netherlands has nothing to fear from global warming. Manmade or not. What we DO have to fear for is misinformed people trying to push every change in their surroundings into the shoes of as yet unexplained phenomena, leading to lots of wrong decisions in politics.
I am one of those people that sees the temperature rise as being well within expected statistical variance, when looking to the last 2000 years or so. I guess that makes me an "unbeliever" and will probably be modded down for it severely. So be it.... ;-)