Lake Sampaloc is one of seven interconnected crater lakes in the Province of Laguna, only 70 kilometer southeast of Metro Manila. Lake Sampaloc is the biggest and the most famous of the seven lakes, located in the heart of San Pablo City known as “City of Seven Lakes” - Bunot, Palakpakin, Mohicap, Yambo, Pandin, Calibato and Sampaloc. These lakes are an important resting ground for migratory birds from the north (China and Japan), e. g. White Egrets.
The Seven Crater Lakes of San Pablo City
The seven lakes are rather small: Sampaloc (1.04 sq. km), Palakpakin (0.43 sq. km), Calibato (0.42 sq. km), Bunot (0.35 sq. km), Yambo (0.28 sq. km), Pandin (0.20 sq. km) and Mohicap (0.14 sq. km). Approx. 250,000 people live in the city region of San Pablo City.
Lake Sampaloc has a maximum depth of 27 meter, the average depth is 20 m. Its width is 1.2 km.
Commercial fish farming at Lake Sampaloc
In 1976, the very first fishing cages were used at the Lake Sampaloc to breed cultured tilapia. 1982 the cages already covered a surface of 6 hectare – almost 5.6 % of the lake surface. Additionally seven years later the cages covered 28 hectares correspond approximately 27 % of the lake’s surface. Nowadays about 40 up to 70 % (seasonal) of the lake’s surface is covered, although only 10 % are legally fixed.
Excess fish feed increases the nutrient level of the lake water, while the big amount of farmed fish and the increasing growth of green algae lower the dissolved oxygen content. There out a grave decrease of the water quality resulted during the last couple of years. Since the Lake Sampaloc is a body of standing water, it has no assimilative capacity which could counteract this ongoing pressure and pollution.
Further pressures through human activities
The Lake Sampaloc has been sorely affected by human impacts for the last decades. Along the shore of the lake several illegal buildings, like restaurants, night clubs, and shanties were constructed. The arising waste and wastewater went right into the lake without any treatment, with the result, that the pollution increased constantly.
For some time now, the drinking water supply for the local population is ensured by springs and fountains of water catchment areas and no longer by the lake water.