The Global Urbanist

News and analysis of cities around the world


RAINS: a surprisingly simple answer to Yemen's water crisis that's ready to scale up?

Sana'a, the capital of Yemen and facing one of the most severe water crises of any city in the world, may have an answer in a startlingly simple project to help households reconfigure their onsite water storage systems to collect their own rainwater.

Cities: Sana'a

Topics: Water, waste and sanitation, Sustainability

A Sana'ani resident is barely visible as he pokes his head above the enormous new tank installed in his home to collect water from his rooftop during the rainy seasons as part of the RAINS initiative. Photo: Sabrina Faber
Runoff water flooding the Sailah on April 9 this year, a causeway that is otherwise used as a major arterial road during the dry season. By collecting water from rooftops before it drains out onto the street network, residents of Sana'a may be able to generate their own solution to the growing water crisis affecting the city. Photo: Sabrina Faber
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The revolutions that swept the Arab world from Tunisia to Yemen have cast a new light on the region both in terms of its underlying issues and future potentials. The uprisings are widely believed to have surfaced due to injustice, inequality and low living standards among many other reasons. Yet other issues are largely overlooked by international circles as fascination with the uprisings, change, revolution and conflict take precedent. One that deserves immediate attention is Yemen's water shortage problem.

Working to address this pressing crisis is Sabrina Faber, a development professional living in Yemen. In 2011 Faber submitted an initiative to the Philips Livable Cities Award Competition and was subsequently awarded the 2010/2011 award for her idea. Dubbed RAINS (Rainwater Aggregation IN Sana'a), her initiative aims to bring immediate impact to the residents of Sana'a as well as to draw attention to the water crisis in Yemen that hinders development and fuels conflict.

To put things into perspective, in 2008 the World Bank estimated Yemen's renewable internal freshwater resources at a significantly low 125 cubic metres per person per year, or 340 litres per person per day. Scarcity occurs below 1,000 cubic metres per person per year, at which point water shortage slows a country's development. The global average was 6,750 cubic metres per year — so far ahead of Sana'a's alarming figure. Most Sana'ani residents are not receiving clean and reliable water.

Rainwater is extremely clean--cleaner than most other water that Sana'anis access--and residents can capitalise on it since the city is not heavily industrialised.

RAINS, believes Faber, offers a simple solution to the water crisis in Sana'a. Yemen has two rainy seasons: one between the months of March and April, and the second in July and August. Rainwater is extremely clean — cleaner than most other water that Sana'anis access — and residents can capitalise on it since the city is not heavily industrialised.

In villages throughout rural Yemen, rainwater is used in a more efficient and traditional way by being captured during rainy seasons for future use, ensuring less dependence on water brought in by a third party. By contrast, in urban Sana'a most rainwater evaporates or lands on pavement which consequently become unsanitary.

What Faber noticed is that every structure in Sana'a has a flat roof, a ground-level water storage tank and a pump. Currently most households receive water from a city provider which is stored in the tank, and a pump — typically electrically operated — pushes water up onto the roof for internal redistribution throughout the building. 'Everything is in place,' says Faber, 'you just need to connect the dots.' The essence of the RAINS project is to use the existing components to capture water from the rooftop instead.

The simple technology has three components: a catchment area on the roof, the storage system which can be in the form of an under- or above-ground cistern, and downpipes to link the two. The RAINS initiative takes the existing components and enhances their capacities by reorienting or adding parts such as downpipes and elbow joints for increased flow into the tank. Additionally, RAINS revamps the current infrastructure by replacing the typical 500 litre tanks with newer ones that have the capacity to store at least 5,000 litres!

The RAINS project takes into account traditional methodologies from Yemeni villages outside Sana'a and adapts them to the city in a way that can be replicated and systematised. Yemen used to be entirely dependent on rainwater for agriculture and personal use, but 'in the past forty years, local and external actors have promoted groundwater extraction over rainwater use. The last two generations have almost entirely abandoned rainwater harvesting. It's time to bring it back,' Sabrina says.

Implementing the RAINS initiative

Currently Faber is piloting the initiative, having completed its fifth pilot site and working on its sixth and seventh. The first step is to ensure that an agreement is in place on each site to set the expectations for the beneficiary. The site agreement assigns one person in the household to be responsible for the system, making sure it is clean and free of obstruction as well as conducting an annual purge to ensure the tank is clear of debris. The installation, however, cannot be managed by a household member — it requires fitting by a plumber and some minor contracting work to ensure it is safely installed and constructed. The household nevertheless is responsible for maintenance to maximise its effectiveness.

What Faber noticed is that every structure in Sana'a has a flat roof, a ground-level water storage tank and a pump. 'Everything is in place,' says Faber, 'you just need to connect the dots.'

As with any international development initiative, sustainability is a key question. RAINS will be 'very sustainable', says Faber passionately; 'water prices will increase and so people have to be more creative about how to get clean and inexpensive water.' Faber goes on to explain the four main water sources theoretically available to a city: freshwater from lakes or rivers, of which Yemen has neither; desalination, which is very costly and requires a huge amount of power and pumping from the coast 250 kilometres away; ground water extraction, which is depleting Sana'a's aquifers; and rainwater, the least invasive and least costly source. RAINS is able to accommodate different ways of collecting rain water to ensure that the process is sustainable and fits with the architecture of most types of building. Furthermore, sustainability is promoted because rainwater collection can be customised according to local needs and through 100 per cent local procurement of hardware and services.

Today RAINS is implementing pilot projects throughout Sana'a and gaining increased attention from both the private and public sectors to integrate rain water collection for water use in commercial and government buildings. The project is being promoted by Philips as well as local media and both private and public sector contacts that Faber maintains connections with. Local contracting firms, the INGO forum, and USAID have all been interested in RAINS as it may prove to be a highly successful avenue for alleviating the water crisis. During tense political times such as these, access to water and addressing the water crisis can offer a resolution to many local, community and tribal disputes. With a simple innovative solution like RAINS, Sana'a is able to have a cost effective way to address its looming fate.


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