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The construction of two rainwater cisterns

“Water is the driving force of all nature”

– Leonardo Da Vinci

This quote is not only valid today but it is even more relevant when we see the steep decline of drinking water reserves globally or the impact that climate change has on the water cycle, just to mention these two.

Since the beginning of our adventure to become regenerative farmers, we know that one of the key pillars in the project is the use of water resources responsibly.

Therefore, we started the construction of two rainwater cisterns that would serve as storage, distribution, and optimization of water use especially in times of drought. Also, this storage of water is extremely important in the fight against wildfires that are quite common in summer.

Several wild fires on neighbouring lands monitored closely by Natural building students September 2020.
Fighting a small bush fire with shovels and hoes before the fire reaches our land.
Wild fires are common in this area during summer. Most of them are man-made!

We discussed several ways of building the cisterns without finding the “right one” until Diego, one of our volunteers with experience in the construction sector, suggested building them in a round form. This would require us to use metal molds to be able to pour the walls in a circular shape. His confidence and motivation convinced us and that is how we started the construction of the first cistern at the end of May 2020.

The first step was to find a suitable location where to build them. They had to be close enough to the house for maintaining a constant pressure (the pump that connects us to the public supply is too far away – due to that we often used to have pressure problems).
An even more important reason for proximity to the house was that we wanted to collect the rainwater from the house roof.

View of the building site at the first stage.
To let gravity do the work for us, we’ve constructed a funnel connected to a pipe
to pour cement from the upper terrace directly into the form. This has saved us a lot of time and back pain 😉

Taking into account that the average rainfall in Badolato is 905mm / year and that our roof surface equals 110m2, we have the potential to store almost 100m3 of water per year.

We chose the closest olive grove from the house to build the cisterns since it is close enough for laying pipes. At the same time, the cisterns would be hidden amongst the trees and not draw too much attention away from the unique landscape.

From the beginning, Diego suggested excavating the holes by hand as the soil is sandy and not too compacted. Despite a certain skepticism, we accepted, and with the help of other volunteers, we started digging.

We used our homemade broad fork from the garden for digging the first part.
One of the metal molds that were used to give shape to the cistern.
Digging manually and with a jackhammer.


The first centimetres were easy to dig but soon we found coarse sand that was very compacted and we had to use a pneumatic hammer.

A metal ring helped us to keep the same right diameter during digging.

The first cistern is 2m wide and 3m deep, which amounts to 9m3 or 9,000 liters. The second cistern measures 2m x 3.5m which generates a capacity of 11m3 or 11.000 liters.

Digging the second cistern.
Detail of the mold and concrete walls.

To ensure waterproofing capabilities of the cisterns we added a finishing painting layer.

Applying a finishing painting layer to avoid any leaks.
A long ladder was mandatory to reach all parts of the big cistern.

At the beginning of July, the cisterns were ready to be filled and we were able to install the pipe system that connects the roof to one of the cisterns to start harvesting rainwater.

View of the rainwater harvest pipe from inside of one of the cisterns. It makes us think about “2001: A Space Odyssey” movie!

After so many weeks of hard work, we opted to hire an excavator to help us with the trenches for the pipes and also to lift the concrete lids onto the cisterns.

The excavator digging the trenches for us.
Installation of one of the lids made of concrete.
Rainwater system connecting the roof to the cisterns.
Construction of the lid.
View of the trenches and Badolato borgo.
Detail of the cistern lid. Metal ring, mesh and hooks.

Both cisterns have submerged pumps that are independent of each other, which allows us to switch between them easily.

The latest step was to build a small housing for all the pipes, faucets, and control units. The natural place for this was right between the two cisterns.

View of the cisterns and housing for pipes and switchers. The ugly orange pipe (we will hide it, promise!) is the one connected to the roof for harvesting rainwater.

The current set-up gives us full control of the water flow, for example, we could decide to pump all the water from one cistern into the other for cleaning purposes.

These are our happy faces reflected on the full cistern while realizing the importance of having such a reserve of water.

After some months of using the cisterns, we can proudly say that the whole project fulfilled all our hopes and expectations.

The system is running so efficiently that we are totally independent in terms of water use except for the driest season. This means that we don’t need to buy any communal water for about half the year! We are very happy to have successfully added some level of self-sufficiency to our lives and to this project.

We want to thank all the volunteers and people involved in this project, especially Diego and Rob who played a key role in the design and construction process. You rock guys!

View of the cisterns area from the top. We can see one of the manhole open.