The geometry of an artificial sea
At the beginning of the year 2026, the Alqueva Multi-Purpose Undertaking sustains a vast territorial grid that benefits around 130,000 hectares of irrigated land, according to records released by EDIA in 2026. This giant infrastructure, erected over decades with accumulated public and private investment that reached 5 billion euros according to data compiled in 2022, has radically transformed the agrarian morphology of dozens of municipalities in the south of Portuguese territory.
To understand the scale of this transformation on the ground of those who live in the region, one only has to look at the intensity of land use in the covered sub-regions. The overwhelming majority of crops installed in this area of influence correspond to permanent plantations, with an absolute prominence for intensive and super-intensive olive groves, as detailed by EDIA in a temporal assessment carried out in 2022.
This agricultural feature contrasts sharply with the traditional dryland farming that historically shaped the Alentejo landscape for generations. The continuous green that can be seen today in the spring results from a profound change in the way water is channeled, distributed, and consumed by a large-scale agricultural business fabric that has progressively replaced small subsistence farming.
The volume and price of abundance
Government management of water resources underwent a structural update in 2026, the year in which the maximum annual volume of water allocated to different uses in Alqueva was increased from 620 hm³ to 730 hm³ per year, fixing at 690 hm³/year the share dedicated to agricultural irrigation, according to joint decrees by the Ministries of Environment and Agriculture published in 2026. Concurrently, the price of water in the Alqueva perimeter was set at 0.0676 euros per cubic meter for high pressure and at 0.0366 euros for low pressure.
To these consumption tariffs are added fixed annual charges per hectare that make the operation more expensive for agricultural producers installed in the region. An annual fee of 63.03 euros per hectare was set in the high-pressure network and 22.92 euros in the low-pressure network, according to official tables approved by the Government of Portugal in 2026.
To put these amounts into perspective against the recent past of farming, the Executive eliminated the reduced water tariff that traditionally applied during the first years of installation of hydro-agricultural developments, according to the same government ordinance of 2026. This decision alters the initial economic model, removing the start-up supports that intensive crops benefited from in the initial phase of commercial maturation.
At about 125% of the contract
Pressure on water availability is reflected in the simultaneous loosening and tightening of usage rules applied to farmers registered in the system. The maximum limit of water use per crop in irrigated land went from 110% to 125% of the initially contracted volume, according to legislative changes introduced by the Government of Portugal in 2026.
Conversely, to curb abuses in abstraction, it was determined that water used above the contracted volume became subject to staged tariff increases that can reach a maximum of up to 400% over the active tariff, according to the same ministerial decree of 2026. This mechanism penalizes excessive consumption, but opens the legal door to supplementary abstractions at a time when the basin faces climatic constraints.
In a retrospective analysis of EDIA's customer base referring to the year 2021, the public company registered 2,675 customers who actively used Alqueva water to irrigate 117,595 hectares, with a farmer adherence rate to irrigation standing at levels above 97%, according to data communicated in 2022. These numbers demonstrate an almost total loyalty to the public irrigation model by the established operators.
Economic salvation and persistent drought
The most obvious reading points to Alqueva as a total and unconditional economic salvation of Alentejo against structural drought, generating unlimited wealth with no visible water costs. However, the State of the Environment reports prepared by APA in 2022 classified national water resources in a situation of persistent water stress, with basins south of the Tagus plunged into full chronic hydrological drought.
To test this apparent contradiction between the artificial abundance of irrigation and the structural scarcity of rivers and reservoirs, it is important to observe the relative weight of the primary sector in the region's overall consumption. Agriculture currently absorbs about 80% of all water consumed in the Alentejo region, according to data put forward by CIMAC in 2023, leaving a narrow margin for remaining human and industrial consumption in years of reduced rainfall.
To mitigate this imbalance in flow management, EDIA began ensuring with APA the weekly and automatic reporting of volumes stored and transferred between the reservoirs of the Alqueva system starting in 2026, according to the Government of Portugal. Concurrently, the 'Regadio 2030' study, released in 2022, projected the installation of another 134,000 hectares of public irrigation and the modernization of another 72,000 hectares, foreseeing a continuous expansion of demand in a scenario of stressed basins.
What is left unwatered in the future
For those who live in one of the 47 municipalities of Alentejo, the hidden bill of this green model is not only measured in the cents paid per cubic meter of water in farming operations. It is measured in the direct competition between volumes allocated to intensive agribusiness and the long-term sustainability of ecological flows and underground reserves that supply local populations in periods of prolonged dry spells.
Decisions made in 2026 demonstrate an attempt at regulation through severe tariff increases for consumptions that exceed contractual limits, but keep the bet on the expansion of high water-intensity agriculture untouched. The transition from a reduced start-up tariff to current prices and penalties of up to 400% reconfigures production costs for the 130,000 hectares currently benefited.
The immediate future of the region is played out in the ability to reconcile the 690 hm³/year consecrated for agricultural irrigation with the climatic reality of persistently strangled river basins. The balance between income generated by permanent crops and the preservation of the essential liquid remains the main economic and ecological challenge thrown upon the Alentejo territory.