A Research Compendium of Rehabilitation Strategies for Damaged, Critical and Marginal Watershed Areas
The Philippines has a total land area of 30 million hectares of which 70% can be considered as watershed areas. These watersheds comprise about 419 principal river basins with drainage areas of approximately 21 million hectares. The most important river basins constitute the Agno and Cagayan River Basins in Northern Luzon, Pampanga River Basin in Central Luzon, Ilog-Hilabangan in Visayas, and the Cotabato and Agusan River Basins in Mindanao.
Out of these watershed areas, 127 are proclaimed watersheds and intended to be managed and protected. However, these were heavily encroached and subjected to various types of cultivation. Consequently, 90% of these proclaimed watersheds were categorized as hydrologically critical, characterized by degraded biophysical conditions and have become risks to downstream infrastructure.
The Philippine watersheds are under the jurisdiction and administration of the Department of Environment and Natural Resources (DENR). Over the years, the management of various watersheds had been transferred to other agencies in order to widen the participation of other watershed stakeholders in watershed management. Some local government units (LGUs) are also active land use managers of some portions, if not the whole watersheds, within their political boundaries. With the enactment of the Indigenous People's Rights Act (IPRA), the indigenous people also serve as administrators over areas within their communities. Some private individuals and corporations are also authorized to take control or regulate the utilization of watersheds in the country under contracts like the Timber License Agreement (TLA) and Industrial Forest Management Agreement (IFMA).
Most of the country's watersheds have undergone massive changes over the years and are currently in varied stages of considered degradation thereby needing deliberate rehabilitation efforts. Continuous attempts are being made to rehabilitate critical watersheds. The government has also launched several programs and projects to rehabilitate degraded watersheds and/or protect those which are still in good condition. However, the alarming rate of degraded watersheds was not effectively addressed by these programs due to: a) insufficient understanding of the dominant biological and physical characteristics of these areas, as well as socio-economic features; b) lack of overall strategy for effective and efficient methods/technologies and lack of trained manpower on watershed rehabilitation; and c) limited financial resources and uncoordinated or fragmented responsibilities in their implementation.
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