There were pictures and temperatures that are actually familiar from July: Southern Europe experienced the first heat wave of the year over the weekend – even though spring hasn’t officially started yet. In Spain, heat records were broken in series. Tourists and locals were at almost 30 degrees on the beaches, from Saturday to Sunday the first tropical night of the year was recorded, with temperatures over 20 degrees Celsius.
But in addition to the much too early onset of summer, the authorities are struggling with an even greater threat: the ongoing drought is a threat to the drinking water supply of entire regions, such as Catalonia. As the regional administration announced, an "extraordinary action" will be launched in the coming days, in which the largest reservoir in Catalonia, "Pantá de Sau", is to be systematically fished dry.
As the Spanish newspaper "El Periodico" reports, the "Pantá de Sau" actually feeds other, smaller reservoirs in the area. It is the starting point for the water supply of an entire region. But now it's running dry. Except for a short phase in December, there was far too little precipitation in winter. Normally, the country's reservoirs are two-thirds full at this time of year. The water level of the "Pantá de Sau" has now fallen to ten percent of its capacity - the lowest level since 1990.
"The drought is exceptional and we have to make the best of the few resources available," explains Elisabet Mas, Action Line Manager of the Catalan Water Agency (ACA). There has never been such a serious situation in Sau, it is an "extreme scenario," she adds.
Because there is no end in sight to the drought, it is necessary to remove the exotic fish species in particular that have settled in the reservoir. Experts assumed that there were at least 50 tons of these fish species in the lake. If the level continues to fall and the water temperature continues to rise accordingly, a fish kill of these species is to be expected. The rotting fish would make the water undrinkable, it said. The effects would be fatal. The remaining 10 percent in the reservoir can support up to a million people for about three months. Should the water go bad, the region's entire drinking water supply would collapse.
"If we don't do anything, the fish will die anyway and affect the state of the water," warns Jordi Ruiz, head of the Department of Climate Action's Exotic Species and Conservation Projects Division.
In order to forestall this situation, up to five fishing boats are supposed to catch about a ton of fish a day from the reservoir in the coming days. Native species are then to be released again into nearby rivers and lakes, and the exotic fish are to be culled.
A similar, albeit smaller, action had already taken place in the extremely hot summer of 2005. At that time, the authorities removed almost 16 tons of fish from the water, as reported by the British "Guardian". Even then, it was feared that the water could become undrinkable due to the invasive fish species.
The lake gained fame throughout Europe last year. The falling water level uncovered the ruins of an 11th-century church tower, as well as a village that had been flooded in the 1960s.
Those: El Periodico, The Guardian