Guadiana River Basin, Spain/Portugal
The Alqueva Reservoir was built in 2002 with the purpose of developing the sparsely populated and water scarce Alentejo region in Southern Portugal. It stores stream water of the Guadiana River basin. Today the Alqueva reservoir is Western Europe’s largest artificial reservoir with a total capacity of 4.15 hm³ and a surface area of 250 km² (Montesinos, 2012).
Figure 3: Alqueva dam in southern Portugal.
The Alqueva Reservoir serves as a multipurpose project and mainly provides water for agriculture, domestic water, and hydropower. The irrigation system associated with the reservoir has a length of 382 km (primary network), while the secondary network has a length of 1,620 km and irrigates an area of 120,000 ha. Until 2025, the Alqueva reservoir will be expanded to irrigate an additional 50,000 ha of land (EDIA, 2019).
Additionally, eight hydroelectric plants, 16 photovoltaic plants, and wind power plants are integrated into the Alqueva multipurpose project to provide renewable energy production (Moraiset al., 2007; EDIA, 2019). The picture below shows a floating PV system near the Alqueva dam in Portugal.
Figure 4: Floating photovoltaic project in the Alqueva dam reservoir.
On the other hand, the Alqueva project has strongly changed the landscape and ecology of the region and downstream water flow.
Other Dams in the Portuguese Parts of the Basin
In the Portuguese parts of the Guadiana River Basin, there are 28 dams. The table below displays only the largest dams within the Portugues hare of the basin.
Table 1: Overview of the largest dams within the Guadiana Basin in Portugal (Source: SNIRH, 2022).
Empresa de Desenvolvimento e Infra-estruturas do Alqueva (EDIA): Brochure- Alqueva: A new land of opportunities. Available at: https://www.edia.pt/wp-content/uploads/2019/06/Alqueva_PT_ES_EN_2019.pdf
Montesinos, S. (2012): System Of Economic & Environmental Accounts For Water In Guadiana River Basin Guaseeaw Final Report (Technical Part).
Morais, M.; Serafim, A.; Pinto, P.; Ilhéu, A.; Ruivo, M. (2007): Monitoring the water quality in Alqueva Reservoir, Guadiana River, southern Portugal. Reservoir and River Basin Management: Exchange of Experiences from Brazil, Portugal and Germany.
Sistema Nacional de Informação de Recursos Hídricos (SNIRH) (2022): Dados de Base. Available at: https://snirh.apambiente.pt/index.php?idMain=2&idItem=1&objCover=920123705&objSite=1627758912