Investment RE-C09-i02

This investment, which is the responsibility of the Intermunicipal Community of Alto Alentejo (CIMAA), provides for the creation of a strategic water reserve that will provide an alternative public supply and allow the establishment of new irrigated areas, providing an integrated response to situations of extreme drought and reducing the probability of flooding.

It will create a privileged environment (lake) for the installation of a large number of floating photovoltaic panels, enabling the reconfiguration of energy production in the region due to its coordination of hydroelectric and photoelectric energy, allowing the accommodation of a photovoltaic power plant which, for 75 MW of installed capacity, would satisfy more than 60% of the region’s current energy needs and lead to a reduction of more than 80,000 tonnes of carbon dioxide emissions per year, while facilitating the diversification of agricultural activity and a qualitative evolution of economic activity, particularly in the agro-industry and tourism sectors. The project provides for the irrigation perimeter to be divided into lots of 100 ha as an incentive for the relocation of people to this highly desertified part of the country, while also introducing a water efficiency system.

The development is located in the Tagus hydrographic basin, in an area close to the boundary of the Guadiana hydrographic basin, and will include the following components:

•  Dam: It will create a reservoir with full storage level (NPA) at an elevation of 248 m, with a flooded area of 7.24 km2 and a storage capacity of 116.1 hm3, which includes an average annual volume of 57.83 hm3/year flows based on the APA hydrological series, making it possible to allocate 50.3 hm3/year to the public drinking water supply, which is essential for ensuring redundancy in the supply to the populations (around 55,000 people) of Alter do Chão, Avis, Crato, Fronteira, Gavião, Nisa, Ponte de Sor and Sousel, and for the irrigation of irrigation blocks. The top of the dam will be at an elevation of 252 m and will have a total height of 52 m and a span of 1,350 m.
•  Mini-hydroelectric power station: To make use of the energy generated by the flows to be released for irrigation in the valley downstream, benefiting from the drop provided by the height of the dam; it will have an installed capacity of 1.0 MW.
• Inflows enhancement system: It will mobilise the water resources of two watercourses that flow downstream from the Pisão dam section (the Chocanal stream on the right bank and the Linhares stream on the left bank), by pumping them into the reservoir, thus increasing the efficiency and resilience of the overall water system. The system will consist of a downstream diversion weir, pumping station and pumping main.
•  System to improve the supply to the Póvoa e Meadas dam from the Pisão dam: connection from the reservoir to be created to the Póvoa e Meadas water treatment plant to guarantee the consumption needs of the municipalities of Alter do Chão, Avis, Crato, Fronteira, Gavião, Nisa, Ponte de Sor and Sousel.
•  Infrastructure in existing agricultural areas: includes irrigation pumping stations, pipelines, regulating reservoirs and distribution networks, irrigation networks and improvement of agricultural accesses, and the improvement of 5,078 ha of new irrigation blocks (Alter do Chão, Avis, Crato, Fronteira and Sousel) is planned. The project provides for the irrigation perimeter to be divided into lots no larger than 100 ha as a way of encouraging the attraction and settlement of people in this area of serious demographic decline.
•  Photovoltaic solar power station (solar panels, inverters, floats and low- and medium-voltage cabling): installation of photovoltaic panels on the surface of the reservoir.

Considered an anchor project for the economic recovery of the Alto Alentejo region, its main objectives are:

•  Contributing to climate transition and adaptation;
•  Contributing to energy transition;
•  Contributing to the digital transition;
•  Providing an effective focus for economic development (estimated creation of 500 direct jobs);
•  Promoting the use of environmental, landscape, heritage and cultural quality.