Geography

The Philippines is an island nation located in Southeast Asia composed of 7,107 islands called the Philippine Archipelago. The geographical coordinates of the Philippines are 13°00’N 122°00’E. The Bashi Channel in the north, the Philippine Sea (Pacific Ocean) in the east, the Sulu and Celebes Seas in the south, and the South China Sea in the west flank of the archipelago. It is the fifth largest island country in the world. The total area of the Philippines is approximately 300,000 Km². The islands are generally mountainous and hilly. Three groups of islands dominate the archipelago’s skyline. The three groups of islands are Luzon, Visayas, and Mindanao. These are further divided into regions, provinces, cities, and municipalities and barangays.

Population and land use
The population of the Philippines was 109.6 million in mid-2019 as per Population Reference Bureau. It is the 12th most populated country that supports about 1.41% of the total world population. The density of the population is 365 persons per Sq.Km. The land used for agriculture is 12.44 Mha, and 8.04 Mha falls under forest cover.

Climate and rainfall
The climate of the Philippines is tropical. The Philippines is known for its tropical climate with high temperatures, high humidity, and abundant rainfall. The climate of the country comprises of two major seasons: (1) the rainy (wet) season, from June to November; and (2) the dry season, from December to May. The dry season may be subdivided further into (a) the cold, dry season, from December to February; and (b) the hot, dry season, from March to May. The mean annual rainfall of the Philippines varies from 965 to 4,064 mm annually. Baguio City, Eastern Samar, and Eastern Surigao receive the highest amount of rainfall while the southern portion of Cotabato gets the least amount of rains. At General Santos City in Cotabato, the annual rainfall is only 978 mm. The average rainfall is about 2,348 mm.

Food and agriculture
Out of the total area of 30.00 Mha, the cultivated area is approximately 10.45 Mha, which is about 35% of the total land area. The arable land is 5.40 Mha, and 5.05 Mha is under permanent crops. There are two cropping seasons in the Philippines. All schemes provide supplementary irrigation to the entire irrigable area during the wet season. The country’s six major crops are rice, corn, sugarcane, coconut, abaca (banana), and tobacco. Except for rice and corn, all these products are exported, along with bananas and pineapples.

Irrigation and drainage
Rural communities and lowland schemes near Manila, manage irrigation development in the Philippines. Irrigation development is highest in Luzon, containing approximately 51.1% of the total irrigated land, followed by Mindanao with 38.7% and the Visayas with 10.2%. The National Irrigation Administration has constructed seven large dams and small reservoirs for irrigation projects with a total capacity of 6,180 million m³. The area under irrigation in the country is 1.52 Mha. In 2009, total water withdrawal was 81,556 Mm3, of which 82.23% was for agricultural purposes, 7.65% for municipalities, and 10.12% for industry. In 2009, freshwater was the only source of water withdrawal, with 78,560 Mm3 surface water and 3,206 Mm3 groundwater.

Water resources management
The Philippines has 421 rivers that swell during rainy months. There are also 59 natural lakes and more than 100,000 ha of freshwater swamps. The National Water Resources Board has divided the country into 12 water resources regions for effective management of water resources. The average annual renewable surface water resources are an estimated 444 Km³. In nine years out of ten, the annual run off exceeds 257 Km3. Groundwater resources are distributed in four major areas covering around 33,500 Km²; 10,000 Km² in Cagayan; 9,000 Km² in Central Luzon; 8,500 Km² in Agusan, and 6,000 Km² in Cotabato. Combined with smaller reservoirs, this aggregated to about 50,000 Km2. The groundwater resources are an estimated 180 Km3/year, of which 80% (145 Km³/year) constitute the base flow of the river systems.

River basins
The Philippines has 18 river basins with an area greater than 1,000 Km2; eight are on the island of Mindanao, seven on Luzon, two on Panay, and one on Negros Island. The smallest river basins are under 50 Km2. The five major river basins, cover more than 5,000 Km² are: Cagayan River Basin in North Luzon (25,469 Km²); Mindanao River Basin on Mindanao Island (23,169 Km²); Agusan River Basin on Mindanao Island (10,921 Km²); Pampanga River Basin near Manila on Luzon Island (9,759 Km²); Agno River Basin on Luzon Island (5,952 Km²).

Water governance
The Philippine Constitution (1987) provides for sustainable water use and water resources management. The Water Code of the Philippines (1976) governs the ownership, appropriation, utilization, exploitation, development, conservation, and protection of water resources. It reiterates that the water belongs to the State and cannot be the subject of acquisitive prescription. Presidential Decree No. 424 (1974) created the National Water Resources Council (NWRC), which was renamed the National Water Resources Board (NWRB) in 1987 by Executive Order 124-A. It has the power to coordinate and integrate water resources development and management activities. Republic Act No. 9275 (2004), also known as the Clean Water Act, applies to water quality management in all water bodies for reduction and control of pollution from land-based sources.

The National Water Resources Board (NWRB) was created in 1974 to coordinate and integrate all activities in water resources development and management. Its main objective is to achieve scientific and orderly development and management of all the water resources of the Philippines consistent with the principles of optimum usage, conservation, and protection to meet present and future needs.

The Department of Environment and Natural Resources (DENR) formulates policies for the enforcement of environmental protection and pollution control regulations. It is primarily responsible for the preservation of watershed areas and ensures water quality for rivers, streams, and other sources of water.

ICID and National Committee
The Philippine National Committee of the International Commission on Irrigation and Drainage (PNC-ICID) joined the ICID in 1956. Mr. A.A. Junio was the Vice President of ICID during 1979-1982. The members of the national committee regularly participate in the annual meetings of ICID. The National Committee can be contacted at pncicid@gmail.com.