What you're, in effect, saying is that universal availability of clean water would contribute to all the problems associated with overpopulation.

Unfortunately, the day that universal clean water is a reality is so far off into the future that many other current assumptions about overpopulation won't be valid.

Right, now overpopulation is a problem mostly confined to Third World countries where women have, on average, more children because of fear that many won't survive childhood.

As cleaner water, and other health related improvements increase the survival rates of children born, all evidence indicates that the number of children born in these countries will decline.

In many developed countries, the rate at which the average woman in producing children falls below the "replacement rate" and the population is actually declining. Look at Japan, some European countries and even Russia.

In other words, the human population will likely decline over coming centuries.

At the same time, better, and potentially unlimited energy sources may be available, like the long expected fusion power, cheap renewables like solar, thorium reactors, etc. Food production can be increased with more efficient agricultural methods, and current high wasteof available food stocks reduced, and hopefully developed country humans will realize they should not over consume food which leads to obesity, disease, and shortened lives.

In the US, computerized bar code cash register scanning has allowed food retailers to efficiently manage their inventories, and has significantly reduced the amount of food, particularly produce, that each store previously had to discard due to spoilage. Technology improvements are making things better all the time.

Land space is not a problem, and if, in developed countries, like the US, if many suburban and rural residents all decided to grow fruits and vegitables on land now used just to grow decorative grass lawns, the nutritious food supply could be increased substantially.

To sum it all up, the universal availability of clean water will make this a better, and more sustainable world, for humans. Not add to overpopulation, disease and premature death. Keep on crunching for clean water, and make the world a better place for generations yet to arrive on the planet.