Mexico: IHE Delft researchers help residents in three towns stave off flooding threat posed by dam
For 16 years, the El Zapotillo Dam has been a source of tension in the Mexican state of Jalisco. The dam in the Verde River, envisioned to solve water supply problems in two major cities, threatened to flood three small towns, putting their residents’ homes and ancestral lands at risk. The residents, who opposed the dam, fought fiercely for their rights, and in recent months garnered success, with Mexican President López Obrador promising that the towns will be protected.
In his third visit to the region in four months, President Lopez Obrador on 10 November 2021 affirmed his commitment to ensure that the dam won’t flood the towns - Acasico, Palmarejo and Temacapulin. He also recognized the residents’ struggle and encouraged them to continue their efforts.
“It is becoming clear that dialogue and mutual respect makes it possible to reach agreements that benefit all,” he said. “I think your struggle is exemplary: for a long time - many years - you persevered and you achieved the goal of not flooding these three towns. This is quite an achievement.”
The town residents sharpened their arguments with the help of IHE Delft PhD researcher Jonatan Godinez Madrigal, who began studying the case of the dam in 2015.
"The dam has long been considered an intractable conflict, but it had not been studied comprehensively,” he said. “Since the start of my research in 2015, I had a clear vision: I wanted to not only contribute to science, but also contribute to resolving the conflict through action research.”
Godinez Madrigal, working with his IHE Delft PhD supervisors, Prof. Dr. Pieter van der Zaag and Dr. Nora Van Cauwenbergh, achieved both goals. By advising residents and proposing workable solutions, he helped the parties involved break a stalemate, and he added to scientific insights.
“We contributed to the understanding of water conflicts and we also co-produced water knowledge that is relevant and impactful," he said. “We did this by opening up our models and actively making them understandable for a wider audience. This could be a basis to build on to resolve other conflicts related to dams, water access and poor water quality.”
The El Zapotillo Dam has a long history that spans over several local and national government terms. According to initial plans, the dam should be 105 metres high – meaning that it would flood all three towns. Construction of the dam never reached that height, however, as it was stopped by a Supreme Court ruling. The existing structure is about 80 metres high and would still flood the towns if used at full capacity.
The IHE Delft team advised the town residents as they evaluated a sophisticated proposal from Mexico’s National Water Commission, CONAGUA, to adapt dam operations and management to make it safer. The assessment showed that this would not fully protect the towns, particularly considering that climate change will increase the occurrence of torrential rainstorms and other extreme hydroclimatic events.
The town residents and IHE Delft experts offered CONAGUA a new proposal that provides stronger protection by retrofitting new spillways halfway up the dam wall, to ensure that the reservoir can never rise to flood levels. This adjustment allows the dam to be used to supply water, but at a lower rate than originally envisioned.
“We need to spend some time to listen to and communicate with people on the ground and avoid restricting ourselves to top-down processes,” he said. “We should try to democratize access to scientific knowledge, so that it can support those who want to change the world for the better.”