The water consumed by approximately 270,000 people in Provence mainly comes from meadows of clover. According to the Symcrau, a group that manages the Crau aquifer, irrigation of these meadows contributes about 70 percent of the aquifer's water, with the remaining 30 percent coming from rain. Every year, 300 million cubic meters of water from the Durance River are directed onto 14,000 hectares of meadows, and about 200 million cubic meters of that water seeps into the gravel beneath the surface. This water is drawn from the EDF canal in Lamanon, which channels 300 million cubic meters from the Durance annually. The aquifer rises in summer, when water use for drinking is highest. Without the canals built starting in 1554, the aquifer would receive almost no water from the Durance. To put the volume into perspective, 300 million cubic meters of water is equivalent to about 120,000 Olympic-sized swimming pools. Spread over 14,000 hectares of meadows, this amounts to more than 21,000 cubic meters per hectare annually, or over 2 meters of water if it remained on the surface. The EDF canal is supplied by the Serre-Ponçon reservoir, and the water flows by gravity into ditches without the need for pumps, eventually reaching the Crau clover fields (which have AOP, or Appellation d'Origine Protégée, status). Farmers take turns opening and closing sluice gates to irrigate their meadows, with irrigation lasting from late March to late September. This results in the aquifer rising in summer rather than in winter, which is the opposite of typical Mediterranean aquifers that swell with autumn and winter rains. In the southwest of the plain, where there are no irrigated meadows, high water levels are observed in winter due to rainfall. This summer recharge is timely, as it coincides with the peak demand for drinking water. However, the exact contribution of irrigation to the aquifer remains uncertain. Different sources estimate it at 70 percent, 66 percent, or "a little more than two-thirds," but no independent studies have verified these figures. Similarly, the population served by the aquifer ranges between 270,000 and nearly 300,000, but all estimates agree that the number is in the hundreds of thousands. The irrigation system began with the diversion of the Durance River in 1554, with Adam de Craponne obtaining the right to do so. Water reached Salon by 1559, and a branch to Arles was created in 1582. Clover was not the original purpose of the canals; they initially supplied mills and gardens. Irrigation of the Crau meadows for forage began in the 18th century. The gravelly soil, formed by the former delta of the Durance, allows water to seep through easily. Without the canals, the Crau aquifer would receive no water from the Durance. The aquifer covers 550 square kilometers and is generally less than 10 meters below the surface, sometimes as shallow as 1 to 5 meters. It lacks an impermeable layer for protection, and withdrawals exceed natural recharge from rain, according to a public platform on environmental services. The aquifer’s health depends on artificial recharge from the Durance-Verdon system, which also supplies drinking water, arboriculture, market gardening, and industries in the Marseille-Fos port area.