Fisheries, which includes capture fisheries and aquaculture, is the dominant use of the Lake. An estimated 13, 000 fishermen depend on the lake for their livelihood. The Laguna Lake produces about 80, 000 – 90, 000 metric tons of fish in a year.
In 1999, the LLDA implemented a Zoning and Management Plan (ZOMAP) to ensure the equitable distribution of the lake’s fishery resources. The ZOMAP allotted 10, 000 hectares for fishpens, 5000 hectares for fishcages, areas for sanctuary and navigational lanes and the rest for open water fishing.
The western part as the most profitable for both capture fisheries and two types of aquaculture. This is due to the regular intrusion of salt water, creating a brackish water environment that is suitable for milkfish.
The lake can still sustain fisheries but is threatened by contamination from pollution. Likewsise, invasive species threatens not only the biodiversity but also poses an alarming impact on indigenous species and on the economic operation in the lake.
The lake also serves as a reservoir for floodwater to save Metro Manila from flooding. The Manggahan Floodway was constructed to divert floodwaters from Marikina River into the lake. The Napindan control station regulates the outflow of excess lake waters and minimizes the inflow of saline water and pollution from the Pasig River.
Laguna de Bay is also used for power generation; three power plants are located in the region. A pump storage hydroelectric power station is operated in Kalayaan, Laguna. Water is pumped up to the Caliraya Reservoir to generate about 300 megawatts of electricity. Efforts are underway to increase this capacity to 600 megawatts.
Laguna de Bay is also known for recreational activities. Although classified only for non-contact recreation such as fishing, boating and sailing, the lake is used for swimming in some communities. Lakeshore resorts near Mt. Makiling extract hot spring waters for health spa and beauty treatment. LLDA also ventures on eco-tourism projects through the LISCOP Component 1 Project with 6 eco-enhancement projects in Rizal and Laguna Provinces namely:
- Daranak Falls Eco-Tourism Project
- Panguil Eco-Park (Ambon-ambon Falls)
- Pakil Eco-Tourism
- Majayjay Eco-Tourism Project (Taytay Falls)
- Cavinti Eco-Tourism Project (Magdapio Falls)
- Siniloan Eco-Tourism Project (Buruwisan Falls)
Laguna de Bay also provides sufficient water for farm lands of the lake region. Studies are being done to further improve the use of lake water for agriculture.
The lake is also being used as a source of industrial cooling water. Major users include the National Power Corporation for the Kalayaan Hydropower Plant and the Philippine Petroleum Corporation Refinery in Pililla, Rizal. KEPHILCO-Malaya Power plant also draws water from the lake for cooling. Cooling water is recycled back into the lake resulting in thermal pollution of about 20 degrees centigrade rise in temperature near the discharge points.
The lake also serves as a huge waste sink for solid and liquid waste coming from households, cropland areas, industries, livestock and poultry production as well as fishery activities. Because not a single municipality is equipped with a sewerage system, pollution is carried as surface run-off through the sub-basins of the lake. In addition, polluted waters from the Marikina and Pasig Rivers also flow into the lake.
SOURCE OF POTABLE WATER
The lake is now a major resource that supplies the domestic water supply requirement of the nearby towns along the lake. This is supported by Board Resolution No. 338, series of 2007- “Declaring the Establishment and Operationalization of Water Permitting, Registration and Monitoring System for the Extraction of the Lake Waters of Laguna de Bay and other Bodies of Water within Laguna de Bay Region and for Other Purposes” and backed-up by the approval of the Implementing Rules and Regulations for Permitting Surface Water Abstraction in 2008. Water permit for Manila Water Services Inc. (MWSI) to abstract a maximum volume of 300,000 cubic meters per day has been approved