This is a more technical review because it was part of a post I wrote for the regrarians.com platform after participating in one of their workshops at Mallorca in 2025, there are many details included and some other info hidden based on the audience it was written for.
The development of the first water retention embankment was done in 2023 with the the following goals in mind:
- to bring a space to have a bath and swim in the summer, it can get really hot here with temperatures over 35°C.
- to observe how nature and the environment develops around it, we’re building a small natural reserve in the property so we wanted to test how it would affect it.
- to obtain a big water retention system in case we want to irrigate a large amount of trees in the future, while it can also help by fighting fires.
At the beginning of that year we contracted Green Curves (https://greencurvesdesign.com/), a local developer who follows P.A. Yeomans work. According to the conversations we had, we defined location, characteristics and the project requirements. Their analysis threw the following values:
In April of that year the excavation started and the work went smoothly, I think the only challenge for them was that the machine broke and it took them ~3 days to repair, while they also found the earth was more wet than they planned so they had to scratch more earth from the hill next to it. That said, about ~10 days it took from start to finish. See attached images.
Particularly, as the area has a natural small flow of water that in summer almost disappears, we decided to sit a 110mm diameter 6m long tube through the wall at the level of full capacity to drain that flow in order to keep the shape and quality of the big overflow that’s necessary for heavy showers.
After about 5 months it filled the 2.5 million liters and we followed the next checks and developments:
May 2023: the dam got some cracks given the amount of water the earth to make the wall had, but as far as we consulted that wasn’t a bad sign, and the growing of vegetation over it would made it more stable.
June 2023: we found that the tube for natural draining got obstruct by vegetation so we decided to put to layers of nets, one big first and secondly a small to avoid it.
July: Before the place got completely full, we decided to sit 4 posts of hard wood to build a small deck. Later, I’d need to finish it over the water which was an interesting challenge. More ahead we decided to build some small wood trails to access and to add a fire stove sauna, which was another big challenge.
September 2023: the place got completely full, the birds were drinking and possibly eating small fishes. Two ducks came to visit. See image attached.
October 2023: I came back from traveling and I put full power to the deck, Panga the cat is already liking it. See image attached.
November 2023: by this time we completed the deck and trail to access to it. We found the water was still quite dark so we decided to add some typhas, indian shots and other native plants, which have grown steady, some of them with the years we found they also they dry and come back again.
December 2023: we still found that the vegetation around it took some time to restore, definitely the effect of big machinery it’s hard even for the first layer of plants.
January 2024: The temperatures have reached very high levels, and even though, it doesn’t’ empty very much – actually after all these years it has only dropped just 10cm below the tube where it drains and comes back again when it rains.
February 2024: from different sources in the area, we heard that it would be a good idea to add some fishes to eat the plants and algae, ours didn’t had much but as a precaution measure we added grass carps. We knew this fish is a big threat to other species, but given that this is an embankment with no contact with other sources of water, we thought it would be a good idea.
March 2024: after almost a year, the dam looks in good conditions, it has received heavy rain and the overflow has worked as expected.
April 2024: we celebrated one year of this project, and I have to admit it surpassed our expectations, if I would have known how much value it added to our life I would have done it earlier.
Many ideas and sub-projects went and are ahead, we’ll see how this evolves. All this work and development is mainly done or managed by me, so it’s a big challenge to prioritize, provide resources and time for it.
