Water Desalination Plants in Andalucia

Water Desalination Plants in Andalucia

Desalination of Seawater

The following plants are constructed. The table below shows their capacity, status and use in 2022.  The reverse osmosis process consumes electricity (4.5 kWh per m3.) and the approximate cost of the water produced is 0.80€ m3. 

*Source 'Plan Hidrológico de las Cuencas Mediterráneas 2022-2027' Anejo VI p62 

Rio Verde Marbella desalination plant
The Rio Verde Marbella desalination plant was a project of the Jesus Gill era following the 1991/5 drought. It was inaugurated in 1997 with a production capacity of 20 hm³ per year. Following a reorganisation the plant was handed over to ACOSOL in 2003 and put into full time service in 2005. The plant takes 124.000 m3 per day of sea water from the mouth of the Rio Verde. The plant filters then desalinates the sea water (40g salt per m3) into fresh water (0.40g per m3) on 7 frameworks supporting a total of 297 pressure tubes with membranes producing 56.000 m3 per day of desalinated water. Salts and CO2 are added to the fresh water before being pumped to the Rio Verde water treatment station where the desalinated water is mixed with rainfall water stored then emitted from the rivers La Concepcion reservoir. 68.000 m3 of brine water is pumped back to the coast every day and discharged 350m offshore and at a depth of 7m on a sand/gravel seabed. The electric power consumption is 4.5 kWh per m3. ACOSOL 2018 documents explain that although the theoretical production is 20 hm³ per year in practice it is actually 15 hm³. However July 2023 the Junta de Andalucia and ACOSOL announced an agreement to invest 20m€ to double the plant's capacity from 5 to 10 (or 12 hm³) per year by summer 2024.  This discrepancy in reported production is due to the reduction in efficiency of old membranes that have never been replaced since the plant was opened. The current production details were further complicated when in December 2023 President of the Mancomunidad of Municipios of Western Costa del Sol announced that the Marbella desalination plant would increase production from 8 to 12 hm³ with the replacement of membranes which were already being fitted. The plant would soon increase production to 20 hm³ under the Regional Government's  fourth anti-drought plan which includes for 'portable' desalination units. The cost of desalinated water is reported as 0.80 € per m3.

El Atabal, Malaga city desalination plant
The desalination plant at El Atabal, Malaga city was constructed in 2005 from an investment of 64 million euro, commissioned by the Ministry of the Environment and Rural and Marine Affairs through the state-owned company Acusur/Acuamed. The plant produces 165,000 m3 of treated water per day ( equivalent to 60 hm³ per year)  which is piped into the Guadalhorse water treatment works. Thanks to the water produced by this plant, the Málaga city did not suffer water shortages or restrictions during the drought of 2004/7. The electric consumption of the running plant is 12,000 kW. This consumption is 0.75 to 1.30 kWh per m3 of desalinated water produced depending on the sea water salt content.  

As means of comparison the largest desalination plant in Europe is Torrevieja (Alicante) which produces 72 hm³ per year. the second largest is at El Prat de Llobregat outside Barcelona which produces 60 hm³ per year.