Until 1976 this lake was an important stopover for wetland birds, including flamingoes in their thousands, winging their way between the Coto Doñana and the Laguna de Fuente de Piedra in Málaga Province. It was also a breeding site for purple swamp hens (aka purple gallinules), crested coot and the rare white-headed duck.
Unfortunately the site was not protected by any environmental legislation and there were no legal constraints on Hefran. It was finally designated as a conservation area in 1986, but the destructive mining activity continued. Various groups of ecologists and conservationists organised protests and petitions demanding that the Junta de Andalucía put an end to the clay extraction, and in 1994 a report by the Junta's own Environment Agency confirmed that the quarry was causing serious environmental damage and should be closed. Four years later, after a lengthy court case, the mining consortium gave up and abandoned the site - but there was no requirement to restore it to its former glory.
Over the next few years Los Tollos was used variously for clay-pigeon shooting, off-road 4x4 racing, and the general plundering of nests and protected wildfowl.The tenacious ecologists didn't give up though. With the Junta de Andalucía now firmly onside and prepared to make a substantial financial contribution, they managed to procure additional funds from the European Union's "Life" programme and begin the process of acquiring the land and planning the project.
Work began in the summer of 2013 to restore the hydrological status quo. They had to pump millions of gallons of water out of the claypits and back into the lake, refill the pits with sand and the clay previously extracted, then remove the dyke which separated the pit from the lake to let the water find its own level again. An educational programme was launched to engage the local population, who participated enthusiastically in the task of replanting trees and vegetation. The total cost was around 8 million euros.
The restoration work was completed last week, and already the birds are coming back. Birding expert John Cantelo reports on his excellent blog Birding Cádiz Province:
"On my first visit in early April 2014 I found the place alive with birds once more, but, significantly, the high water levels were no longer simply a matter of fortuitous winter rain, but of careful planned management. The birds included Purple Gallinule, over 30 Black-necked Grebes, half a dozen Flamingos, similar numbers of Spoonbill, a good variety of ducks (Pochard, Red-crested Pochard, Gadwall, Shoveller & Mallard), a couple of dozen Whiskered and a few Gull-billed Terns, Avocets, Black-winged Stilts, Little Ringed Plovers, Collared Pratincoles and in excess of 300 Coots (perhaps a hopeful sign that Crested Coot may soon return). A subsequent visit in early May produced similar range of species plus several passing Curlew and Common Sandpipers and, best of all, 3-4 White-headed Ducks. Some eight birds are present this summer and hopes are high that they may soon breed once more. Other birds present on the reserve this spring include Purple Heron, Little Bittern, Great-reed and Melodious Warblers. Later in the season the tamarisks here should also be worth checking for Olivaceous Warblers. Black-winged Kite are present nearby and during passage almost anything might turn up. I certainly found much more of interest on my two visits to Laguna de los Tollos this year than I managed to find at Laguna de Medina, a much better known and more highly regarded site."