Current sources of our water supply presently generate 1,025 million cubic meters (Mcm) per day.  This fresh water supply comes from two sources: 1) surface water, such as principal river basins, streams, and lakes; and 2) ground water.  At present, there are 112 major groundwater basins identified nationwide that serve as actual sources of water supply.  Of the watersheds, 18 are major sources serving domestic and industrial requirements while 85 are sources of agricultural supply With an average annual rainfall of about 2,400 mm, the total annual renewable freshwater available is estimated to be 323 billion cubic meters (Bcm). (Source: National R&D Program on Water Resources Management, 1998).  

Seemingly abundant, water in the country has become a limiting factor in agricultural as well as industrial development, not to mention its domestic purposes.  This is not only because of the naturally unequal distribution of water due to differences in geographical and climatic conditions.  If dependable water supply values are used, Region 3 may become a distressed area, and 5 other regions  (Regions 5, 6, 7, 11 and 12) may become borderline areas in so far as water supply adequacy is concerned by the year 2000.  

Available water is also decreasing due to increased competition for the different uses of water brought about by increased population, industrial and economic growth.  In 1990, the demand for agricultural sector constituted a large share (87%) of the country’s water consumption, while industrial and domestic consumption retained a small percentage, 8% and 5%, respectively.  However, while industrialization is being promoted in the country, percentage share of industries to water consumption tend to increase from 8% to 16% by year 2000.  The agricultural sector’s share will be less to about 76%.  The percentage decrease in the agricultural sector would be absorbed by the industry with a small percentage shifted to domestic consumption (8%).  

The degradation of the watersheds due to deforestation and encroachment of agricultural activities in the forests further aggravate the decline in water availability.   
   
Moreover, the deteriorating water quality due to increased pollution or contamination has also caused a reduction in available water.  Pollutants come from domestic sewage and garbage; municipal wastes from public markets and slaughterhouse; oil spills from gasoline stations, barges and boats; agricultural chemicals; untreated or partially treated waste water from industrial operation, such as food processing plants, pulp and paper mills, textile mills, sugar mills, distilleries, poultry farms, etc.  As of 1994, the 65 designated water monitoring stations located in various parts of the country, reported that water quality no longer met the standards of beneficial use for which it was classified.  In 40% of river stations and 60% of coastal stations, water quality was lower than the worst classification.   

In view of this, most of the work on water resources revolves around management techniques to conserve and protect water resources in order to increase its availability and quality for its different uses.  Presented below are the research and development efforts that have been done in trying to address the problems in our water resources.   

 Assessment and evaluation of water resources   

• Characterization of watersheds in the country 
• Analysis of hydrologic data 
• Databank on benchmark information on land and water resources, including streamflow records of the country's major river basins, rainfall probability analyses and other climatic data 
• Evaluation and assessment of groundwater resources for irrigation 
• Remote sensing techniques for the inventory of water resources for irrigation 
• Computer simulation for predicting optimum use of water resources for irrigation 
• Agroclimatic data collection and analysis 

Water conservation structures    

•  Small farm reservoirs (SFRs) 
•  Small Water impoundments (SWIM) 
•  Diversion dams 

Watershed management and utilization   

• Basin approach in the management and rehabilitation of degraded watersheds (Laguna Lake, San Cristobal River, Molawin River, Pasanjan /Lumban River System, Tanay River System) 

 Water augmentation or supplemental water sources   

•  Shallow tubewell irrigation system 
•  Groundwater utilization for agriculture 

Water use efficiency   

• For upland crop-based farming system, studies conducted include water use of crops, appropriate levels of irrigation for different management and environmental conditions, furrow irrigation, and subsurface irrigation 
• Management of irrigation systems for crop diversification (upland crops after Agricultural Ecosystems), which include consumptive use of water or evapotranspiration, water requirement of crops, amount, frequency and scheduling of irrigation 
• Drip irrigation systems for local conditions 
• Development of drought-tolerant crop species for pole sitao, pigeon pea, cowpea, bush sitao, tomato, eggplant, corn, mungbean, sweet potato, cassava, tobacco, and forage and pasture grasses 
• Water management and rehabilitation of National Irrigation Systems (NISs) and Communal Irrigation Systems (CISs).  Among studies conducted involve Agricultural Ecosystems irrigation water requirement, water distribution, conveyance losses, water re-use, water use efficiency, farm irrigation efficiency through water balance studies, collection of hydrometerological data, water quality analysis, soil moisture stress, and sedimentation studies. 

Drainage   

• Inventory of drainage problem areas (low-lying areas or plains along rivers in Central Luzon, Pangasinan, Cagayan Valley, Occidental Mindoro, Bicol, and some provinces of Visayas and Mindanao 
• Evaluation of drainage systems and facilities 
• Development and testing of materials for drainage 
• Evaluation of crop response to different drainage systems 
• GIS system for assessing flood prone areas 

Socio-economic studies on water management   

• Assessment of water pricing policy 
• Marketing system for crop diversification 
• On the NISs and CISs, socio-economic studies addressed conflict management, irrigation fee collection, organizational structures, system management, operation and maintenance. 

Information system    

• Information system for water management (developed by CLSU) 
• Computer simulation for predicting optimum use of water resources for irrigation