[See table]

In 2003, the Department of the Environment and Natural Resources – Cordillera Administrative Region embarked on a master plan for the Lower Agno River Basin (LARB). Part of this Plan involved the determination of the volume of water resources in the area. This could only be done through the implementation of a Water Resource Accounting (WRA) which is possible under the framework of the Environment and Natural Resource Accounting (ENRA) system.

Accounting for water involves two physical accounts – that of ground water and surface water. Due to data limitations concerning LARB, this resource accounting involved only surface water. Accounting for the surface water of the LARB for the period 1999 – 2003 showed that the stock has been declining by an average of 158.8 million cubic meters (MCM) annually. This is about 7.6 percent of the average annual stock (2,080.1 MCM) for the accounting period of five (5) years.

For the whole accounting period, agriculture had been the major contributor to abstraction. In 2003, agricultural abstraction accounted for 97.1 percent of total abstraction with households consuming only 2.9 percent of surface water.