The source of the River Tordera is located 1,100m above sea level, in the heart of the Montseny Massif in the Catalan Pre-Coastal Range. The river flows for 55km, before then discharging into the Mediterranean Sea.
The river is well known for its richness of biodiversity, which is now safeguarded by various environmental protection measures. And it runs through two natural parks – Parc Natural de Montseny and Parc Natural del Montenegre i el Corredor.
The river’s main tributaries are the Riera de Valmanya, Riera de Gualba, Riera de Arbúcies and the Riera de Santa Coloma.
The river’s average discharge is about 5.01 cubic metres per second.
Challenges facing the river basin
In the spring and autumn, this unregulated river can be subject to flash floods, known as ‘Torderadas’. And in the summer, it’s not uncommon for the river to experience a drought.
Because of this, groundwater takes precedence over surface water, in terms of supplying the local area, which is home to nearly 330,000 people.
Most of the local population live in the intermediate section and delta area. And in the summer, the influx of tourists to the area means that the coastal areas put an even bigger strain on the local resources, including water.
Other factors putting a strain on the river basin are horticulture in the coastal areas, and bottling industries in the upper course of the river.
Shallow irrigation in coastal areas for horticulture is causing saltwater intrusion, which is a cause for concern in that it could contaminate an important local drinking water source.
And the bottling industries in the upper course of the river are currently producing around 27% of all the mineral water consumed in Spain.
Waste management is also an issue in the river basin. Due to the lack of provision of treatment facilities, some of the smaller local communities releasing their waste directly into the river.
And finally, of course, climate change is having an effect on the river basin. It’s believed that the river’s flow could decrease by as much as 30%. And rising temperatures will soon make many of the tree species in the area unsuitable. As the area is largely covered by forest, this is a major cause of concern, particularly due to the increased risk of forest fires.
What’s Being Done?
All this has led to concerted efforts to better manage the river basin.
In terms of improving its sustainability as a water source, measures undertaken include installing a desalination plant and the development of different water recycling initiatives.
The intention is to use a combination of these new water resources and the natural resources to reduce the pressure on the river basin. The downside to this, however, is that these measures are expensive and so will raise the price of water for locals.
In terms of waste management, there are plans for the development of depuration. But a lack of funding and coordination are slowing down the process of improving the river’s chemical quality.
Forest management will also be important to securing the future of the Tordera river basin. Ensuring that the forests are properly controlled will reduce the risk of forest fires and could even help sustain the freshwater runoff that feeds the river.