Geography of the Philippines Bay. Laguna de Bay, east of Manila Bay, is the largest freshwater lake in the Philippines. Several rivers have been harnessed for hydroelectric power. To protect the country's biological resources, the government has taken a first step of preparing a Biodiversity Action Plan to address conservation of threatened species. The islands are volcanic in origin, being part of the Pacific Ring of Fire, and are mostly mountainous. The highest point in the country is the peak of Mount Apo in Mindanao, which is above sea level. The second highest point can be found on Luzon at Mount Pulag, a peak
Laguna de Bay as a source of water for the Kalayaan Pumped-Storage Hydroelectric Project in Kalayaan, Laguna. Other uses include fishery, aquaculture, recreation, food support for the growing duck industry, irrigation and a "virtual" cistern for domestic, agricultural, and industrial effluents. Because of its importance in the development of the Laguna de Bay Region, unlike other lakes in the country, its water quality and general condition are closely monitored. This important water resource has been greatly affected by development pressures like population growth, rapid industrialization, and resources allocation. Known lake islands include Talim, the largest and most populated island on the lake; Calamba