Why rainwater?

According to the United Nations the world faces a water deficit of 40% by 2030.
It is imperative to take action today to have water tomorrow.




1. Communities without water


More than 10 million Mexicans do not have access to water services. In DF alone, at least 250,000 people live without connection to the network and millions more have an intermittent service or receive contaminated water.


A rainwater system can supply a large quantity of water and supply a family for 5 – 12 months of the year. With good design, the water can be used for all household uses, even to drink!

2. Flooding

Every time Mexico City suffers from severe flooding, the drains are flooded with enormous amounts of rainwater.


With rainwater harvesting, instead of contaminating and saturating the drainage system, we could use this water to fill cisterns!

3. Sinking of the city

In Mexico City, 70% of the water that we use comes from aquifers directly underneath the city. The extraction has been so extreme that the city has sunk more than 10 metres in the last 100 years!


Harvesting the rain when it falls on our roofs, enables us to reduce the amount of water we have to pump out of the aquifers, slowing and perhaps eventually stopping the sinking of the city.

4. Decline of the Aquifers

Mexico City is ranked third in the list of major world cities facing extreme water stress. This is because we extract from the aquifers and rivers, much more water than is naturally recharged. If we maintain this trend, our sources will cease to exist in the not too distant future.


If the roofs and buildings of the city capture rainwater instead of allowing it to flow into the drainage, we could extract less water from underground during the wet months and allow the aquifers time to naturally recharge. We need to reach a water balance with the aquifer to ensure that it can give water during the dry season.

5. Cost of Energy and Resources

30% of the water supplied to the Mexico City network is provided by the Lerma-Cutzamala system. This water is pumped from a distance of 150km away and vertically 1km over mountains from sources outside the Valley of Mexico.
The energy cost to pump all this water is equivalent to the total electricity consumption of the city of Puebla!


In the zones where supply from the network is poor, the capture of rainwater becomes hugely important, reducing the need to pay for thousands of water trucks (pipas) each year and saving large amounts of energy, money and resources for families and the authorities responsible for the supply.

6. Rainwater harvesting: Changing paradigms to manage water

“It is inconceivable that here, where we are drowning in rain and flooding, yet at the same time we are going without water to drink”
José Luis Luege Tamargo, Ex Director Conagua (2006-2012).


We are working to promote the uptake of rainwater harvesting and to learn to do it in the most effective way possible, seeking to develop to the point where rainwater harvesting can be incorporated effectively into the water infrastructure of our city.

To learn more about the problem, visit our library where you can find documents about the issue! (Spanish index)