Since being declared a World Heritage Site, there have been attempts to rescue the canal system. The first major effort occurred between 1989 and 1994, which was called the “Rescate Ecológico.” It had the goal of constructing a large artificial lake for tourism and sports covering 360 hectares, ten times the size of the lake in Chapultepec Park. These would be divided into two parts called the Ciénega Grande and Ciénega Chica on the side of the Periférico Sur. It would also include the creation of a chinampa zone and areas for culture and commerce and elevated buildings over the two sides of the Periférico Sur similar to those in the San Jerónimo area. However, this plan was stopped by agricultural communities in the area, which have a long history of defending their rights. However, since then, the area has been urbanized. It was replaced by a much smaller lake, with ecological area and plant market. In 2008, borough authorities began a reforestation program over 5,000 hectares of chinampas and forested areas at a cost of 20 million pesos. This program includes the cutting of non native species such as eucalyptus and certain pines and cedars to eradicate plagues associated with them. However, residents near forests such as in Nativitas oppose the cutting of healthy trees. These will be replaced by native species, especially junipers in the chinampa areas. However, it is still estimated that because of the continuance of urban sprawl, the remaining canals and protected land will disappear within fifty years.