Case Study: Pond and floating cover of the “La Volaera” Irrigation Community

Location Zafarraya, Granada

Area 225 hectares in the municipal terms of Alhama de Granada and Llano de Zafarraya (Granada), with 75 and 150 hectares, respectively.

Capacity 450,000 m3 (130 Olympic-size swimming pools)

Material used: Alvatech HDPE Geomembrane / PET 300 gr Geotextile

Background

ALGEO, a specialized and leading company in irrigation installations, hydraulic infrastructure, water treatment, and floating cover execution, has been responsible for the waterproofing and floating cover project for the “La Volaera” Irrigation Community.

The project includes one of the largest floating cover ponds in Spain for water storage. With a capacity of 450,000 m³, the ALVATECH 5002 geomembrane from Sotrafa was chosen as the waterproofing solution.

The irrigation area is entirely located within the municipalities of Alhama de Granada and Ventas de Zafarraya. This project will benefit 196 community members, enabling the cultivation of vegetables and fruit trees.

Thanks to the floating cover, an annual water savings of 85,000 m³ will be achieved by reducing evaporation. The unique water characteristics of the endorheic basin of Zafarraya allow the community to fill the pond to 100% capacity during the winter months, ensuring the necessary supply for the irrigators during the months of highest water demand in the summer.

Challenge

This project aims to provide the community with new water storage for irrigation, minimizing the overexploitation of the aquifer and utilizing rainwater to replace the extraction from the underground or the main canal. The construction of this pond seeks to ensure irrigation during the central months of July, August, and September, and to reduce the exploitation of nearby aquifers. This will benefit 196 community members from the municipalities of Alhama de Granada and Zafarraya.

Solution

The chosen solution for this waterproofing is the ALVATECH 5002 geomembrane, 1.5 mm thick and smooth on both sides. A total of 110,000 m² of ALVATECH geomembrane has been installed on a 300 g polyester geotextile.

Furthermore, due to the high temperatures during the months of June, July, and August, and to prevent water loss through evaporation, a floating cover has been installed. This cover not only ensures water quality for irrigation by preventing algae growth but also protects local fauna by preventing them from falling into the reservoir.