On 11 April, just ahead of the IMF-World Bank Spring meetings in Washington DC, a group of 80 government ministers from around the globe are gathering to promise to do more to bring safe water and decent toilets to those without.
It has been two years since a similar group of ministers from developing and wealthier nations made similar pledges, and events since then have shown us why this time around is more important than ever.
Since then, the world has been gripped by unusual and often devastating weather patterns. We've seen drought in southern Africa, Australia and parts of the United States, and dramatic flooding in the UK, Central Europe, India and Indonesia. All of these make creating and maintaining safe drinking water supplies and sanitation systems more challenging, particularly in developing countries where infrastructure is fragile and easily destroyed.
We've seen the eradication of polio in India through a massive vaccination effort - a stunning public health victory, but threatened by the country's struggle to improve safe water and sanitation services, since polio thrives in their absence.
Still 748 million in need of safe water
Despite the world's efforts, this week a Joint Monitoring Programme of the WHO and Unicef has revealed that some 748 million people are still without safe drinking water and 2.5 billion are without access to decent toilets. The latter number has remained largely unchanged in more than a decade.
One child dies every minute from diarrhoeal diseases linked to unsafe water, bad sanitation and poor hygiene -- illnesses that are completely preventable.
So we at WaterAid look to the 11 April meeting with strong expectations. UN Secretary-General Ban Ki-moon and World Bank President Jim Yong Kim will lend their voices to the call. This is our moment to convince the international community to deliver water and sanitation to everyone, everywhere, forever, and within our lifetimes.
It is a crisis of incredible proportion, and it needs to be addressed now.
This year is a critical time for progress in water, sanitation and hygiene. The United Nations is in the final stage of outlining its agenda for reducing international poverty beyond 2015. The original UN Millennium Development Goals run out next year and will be replaced by a set of sustainable development goals. Water and sanitation need to be among those goals.
There is momentum. We have had calls to action from the UN Deputy Secretary General, Jan Eliasson, and the President of the UN General Assembly, John Ashe. UN Secretary-General Ban Ki-moon has called the need for access to safe drinking water, sanitation and hygiene "a matter of justice and opportunity."
But this fight cannot be an exercise of words alone. The Sanitation and Water for All High Level Meeting cannot become a place for lofty promises that are soon forgotten.
We need more commitment and accountability from both donors and developing countries to make this happen. We need to work with public and private partners on both financing and delivery, to make sure investment in good work is sustainable and long-lasting.
The gap to bridge is massive. In southern Africa alone, the gap in financing to put countries back on track on water and sanitation amounts to $3.6 billion US per year.
That means 36 million people in southern Africa who should have received clean water by 2015 will miss out, and another 66 million will go without sanitation.
There is a tremendous economic cost to this, from lost productivity and missed work and school days stemming from illness or time spent searching for water or a safe place to defecate. The economic impact of inadequate sanitation in India alone is estimated at over £34 billion. Poor sanitation in Nigeria costs nearly £2 billion a year.
Safe water and sanitation mean better health, a better chance at survival for mothers and their newborns, better education, better nutrition and stronger resistance to illness. They also create a safer environment for women and girls, by removing the vulnerability that comes with long walks for water or open defecation and empowering them to spend their time on education, generating income or caring for their families.
These are basic human rights, and extreme poverty cannot be eliminated without them.