The international system is often accused of failing to give adequate early warning; of being myopic and not furnishing the appropriate powers with data and analysis that would allow an effective, timely response to predictable disasters. With the recent publication of the report, Gaza in 2020: A Liveable Place?, it would be hard to level these accusations at the UN country team in the occupied Palestinian territory. The report is a trend analysis based on data from authoritative sources, such as the UN’s specialised agencies, the World Bank and the International Monetary Fund (IMF), which sets out where Gaza will be in less than eight years’ time. This is early warning writ large.

By 2020, the population of the tiny Gaza Strip will grow by half a million people: 500,000 more to be fed, housed, educated, employed. More than half of the population will be under 18, with one of the highest youth populations as a proportion anywhere in the world.

The lack of safe drinking water is the most urgent concern in Gaza today and it will only get worse in the years to come. The coastal aquifer is the main water source, but 90 per cent of its water is not safe for drinking without further treatment. Three times as much water is currently extracted from the aquifer as is recharged from rainfall every year. This situation is not sustainable. By 2016, the aquifer may become unusable and damage to it may be irreversible by 2020 without remedial action now. Already, people have to drill deeper and deeper to reach groundwater. The UN Environment Programme recommends resting the aquifer immediately, as it would otherwise take centuries for it to recover. At the same time, demand for water is projected to grow to 260 million cubic metres per year in 2020, 60 per cent more than is currently extracted from the aquifer.

Only one quarter of sewage is currently treated. The remaining three quarters are dumped into the Mediterranean sea. Based on population growth, the amount of sewage and waste water that is generated per year could increase from 44 million cubic metres today to 57 million cubic metres in 2020. Current treatment plants need to be expanded and improved and new ones built.

These predictions have profound implications for all humanitarian and development organisations in Gaza, in particular the UN Relief and Works Agency (UNRWA) which works with Gaza’s refugee communities. Some 70 per cent of the population are refugees, with UNRWA’s current caseload of more than 1.2 million expected to rise to some 1.5 million by 2020. This 30 per cent increase in refugees will require massive investment to maintain current levels of services.

Take health: In 2011, there were over 4.4 million patient visits to UNRWA health centres. That could be expected to rise to more than 5.7 million annual visits at current rates. UNRWA’s 21 health centres currently have an average catchment of approximately 57,000 registered refugees; without new clinics that would rise to more than 74,000 by 2020. To bring UNRWA closer to World Health Organisation (WHO) standards, the agency currently needs an additional 90 doctors and 95 nurses. To maintain current service levels by 2020, UNRWA would need to add five new health centres, 220 doctors and more than 300 other health professionals and that is without improving the present level of service (more than 100 patient visits per doctor per day).

In the education sector, urrently UNRWA has 247 schools in 130 buildings, with 93 per cent double-shifting the same building, serving two separate shifts of students and teachers each day. To maintain the current student-teacher ratio, Gaza would need more than 2,000 teachers and support staff.

On social protection, UNRWA distributes food to more than 900,000 refugees, after which some 44 per cent remain food insecure because of a lack of jobs. Without improvements in the economy, that can only come about with the lifting of the blockade, that figure will rise to more than one million. An additional 350,000 refugees by 2020 means some 20,000 new shelters will be required.

Our prescription to avert this looming but avoidable catastrophe is simple. While the UN has condemned the rockets many times, we continue to demand a lifting of the blockade, which is costing the international community hundreds of millions of dollars each year. Allow the people of Gaza to enjoy the standards of development and economic prosperity for which they yearn. They are capable of self-sufficiency. They do not want the current levels of 80 per cent aid dependency to continue and neither do the world’s taxpayers, who fund the international aid agencies. Let us address the root causes of this looming disaster rather than expecting the international community to foot the bill to mitigate their disastrous consequences.

Robert Turner is Gaza director for the United Nations Relief and Works Agency for Palestine Refugees.