WATER QUALITY MONITORING
Laguna de Bay is a strategic political, economic and ecological resource that has to be managed well as a Living Lake, capable of sustaining life, livelihood and economic progress in the region and its environs.
Laguna Lake Tributaries
Interactive Map 1. Map showing the selected river system daining into the Manila Bay
- Lake Surface Area: * 900 km2
- Lake Average Depth: ~ 2.5 m
- Lake Maximum Depth: ~ 20m (Diablo Pass)
- Lake Average Volume: 2,250,000,000 m3
- Retention Time: ~ 8 months
- Watershed Area: * 2,920 km2
- Shoreline: * 285 km
- Watershed Population: ~ 12 M (NSO 2000)
- Biological Resources:fish, mollusks, plankton macrophytes
- (* At 10.5m Lake Elevation)
Based on integrated approach on Watershed Management, the River Rehabilitation Project was launched in 1996 by Laguna Lake Development Authority (LLDA). The program was revived in 2010 wherein LLDA partnered with different stakeholders. The water quality assessment of the Sta. Rosa River System was carried out by the ELRD during the months of March and September 2012 representing the dry and wet seasons. The objectives of the study are: (1) to assess the present condition of the river in terms of conformity with the 1990 Water Quality Criteria set for Class “C” Waters by the Department of Environment and Natural Resources (DENR)~ and (2) to provide and compare the previous baseline data on the present river’s characteristics based on its biological indicator organisms such as algal population, the benthic fauna and the presence of the Coliform group of bacteria that will serve as reference for the Rehabilitation Programs to be implemented in the Sta. Rosa River System.
The rivers of Cabuyao are Cabuyao River between the boundary of Santa Rosa City and Cabuyao, Niugan-Sala River along the boundary of Barangays Niugan and Sala, Tiway-Tiway River, and San Cristobal River between the boundary of Calamba City and Cabuyao. The municipality is politically subdivided into eighteen (18) barangays in which six (6) of them are situated along the lake, namely: Bigaa, Butong, Marinig, Gulod, Baclaran and Mamatid. In 2004, the data from the Municipal Agriculture Office showed that the municipality had a total of 940.56 hectares riceland (or 9.4056 in square kilometers) while the total number of farmers for the same year was 468. The ricefields/ricelands in Cabuyao are found in Barangay Bigaa, Butong, Marinig, Gulod, Baclaran, Mamatid, San Isidro, Pulo, Banay-Banay, Niugan and Sala.
The Morong River, also referred to as the Morong Teresa River, is a river system in the province of Rizal. It is one of the 21 major tributaries of Laguna de Bay. It covers fourteen (14) barangays and stretches up to 10 km from Antipolo City down to Teresa and Morong, Rizal and finally to Laguna Lake. The Morong River sub-basin has a drainage area of 70.2 sq.km.
Sapang Baho river is one of the tributary rivers draining to Laguna de Bay and is one of the priority tributary rivers under the LLDA’s River Rehabilitation Program. One of the priority programs in support of the River Rehabilitation Program is the conduct of water and sediment quality sampling of Sapang Baho River led by the Environmental Laboratory and Research Division (ELRD). Water quality sampling was done on February 02, 2011 (for the dry season) and August 16, 2011 (for the wet season).
Santa Cruz River is one of the 21 major tributary rivers of Laguna de Bay contributing about 15% of the total water in the lake. During the typhoon “Milenyo”, the Calumpang Diversion Dam was destroyed due to overflowing of the river. Built in 1970, the dam channeled irrigation canals around the Calumpang area. The water is used as a source of irrigation for 2185 hectares ricefields in Pila, Santa Cruz, Liliw, Victoria and Nagcarlan. The riverbed is characterized by rocks, pebbles to sandy bottom where quarrying along the river was also one source of income aside from fishing. According to the National Irrigation Authority, quarrying could be the cause of erosion and deepening of riverbed to 12 m lower than the old depth. The width and length of the river could be comparable to Pagsanjan River. However, the volume and capacity of Santa Cruz River were exceeded during the tropical cyclone “Santi” (2009). Santa Cruz River submerged 85% of the town, 6 ft at Brgy. San Pablo Norte, waist-deep at Brgy. Santisima Cruz and San Pablo Sur while leg-deep at Brgy. Inang Awa.
The Municipality of Tanay is a 1st class municipality in the province of Rizal, Philippines. It is located 57 kilometers east of Manila, although a typical commute between Manila and Tanay will take between one to three hours depending upon traffic conditions. It contains portions of the Sierra Madre Mountains and is bordered by Antipolo City in the northeast, Baras, Morong and Teresa in the west, General Nakar (Quezon Province) in the east, and Pililla, Santa Maria (Laguna province) as well as the Laguna de Bay in the south. According to the latest census (2007), it has a population of 94,460 people in 15,720 households. The majority of the population consists of Tagalogs who live near Laguna de Bay, though there is also a significant percentage of mountain dwelling people living in the northern portions of the municipality.
LLDA’s Administrative Jurisdiction
- Total no. of cities = 14
- Lakeshore municipalities = 25
- Non-lakeshore municipalities = 22
- Total no. of barangays = 2,656