The effects of fresh water dams
Caussade's illegal water dam, in the south-west of France, highlights the water supply issues currently raised by farmers, activists and politicians all around the world.
With the recent climate change, droughts became frequent in France for the misfortune of farmers (growing water demanding arboreal fruits and corn). 20 years ago, Lot-et-Garonne's agriculture committee made the wish to order a water dam to irrigate the Tolzac basin. In 2017, various environmental agencies advised to not proceed with the project. Nevertheless, in 2018 local authorities granted authorisation to start building the dam. Later, State authorities reported the project’s ecological flaws on court, but when judge ordered cops to close the construction site, 300 farmers interfered and their work continued until completion at the beginning of 2019. They now benefit from 420000m3 water per year to secure their production during this Summer drought.
Since Rémy Fraisse's death in 2014 during confrontations between cops and activists defending lands where Sivens's dam was planned, those projects were supposed to be negotiated in a legal framework calling on all concerned parties. Dams like the one in Caussade are small enough to be naturally resilient. What worries activists is their possible multiplication all around the country — dams being considered an inefficient way to manage water.
As hydrologist Willem Vervoort explains, dams lose large amounts of water through high evaporation and they have a limited lifespan due to sedimentation at their bottom. In his homeland, Australia, the Murray-Darling Basin Plan (2012) accounts as how disastrous dams can get, when socioeconomic values are prioritised over sustainability. Farmers legitimately struggle to face climate change, but they should bet on smart water management solutions: better crop varieties, more efficient water application and irrigation layouts, improved water infrastructure and education. Unfortunately, dams are a visible political statement in dry weather countries, but they do not garantee a change of farming systems.