Assemblée générale 2002 - Québec, Province de Québec - Canada, 28 - 30 mai 2002
2002 INBO's General Assembly - Quebec City - Quebec - Canada, May 28-29-30, 2002
Asamblea General de la Red 2002 - Ciudad de Quebec, QUEBEC - CANADA, 28 al 30 de Mayo de 2002

WATER RESOURCE STRATEGIES FROM THE LAGUNA DE BAY WATERSHED, PHILIPPINES

Alicia E. Bongco Division Chief, Laguna Lake Development Authority

Abstract

The Laguna de Bay watershed has a total area of around 3,730 km2 covering 6 provinces, 49 municipalities and 12 cities. It spans 2,656 barangays of which 187 are all within lakeshore towns in Southern Tagalog in the Luzon Province. The watershed is subdivided into (a) the Lake Subsystem which consists of 24 sub-basins directly draining water to the Laguna Lake and (b) Marikina Subsystem which generally drains water directly to Manila Bay through the Pasig River.

The strategic resource of the Watershed Region is the Laguna de Bay which is situated in the midst of the country's center of urban and industrial development. It is considered one of the largest lakes in Southeast Asia and most vital inland body of water in the Philippines, with its surface area of some 900 km2 with around 100 streams draining into it. At present, the lake or bay has an average depth of 2.5 meters and holds an average total volume of 2.9 billion cubic meters of water.

Conflicts among the various uses are apparent in Laguna Lake as well. Aquaculture development competes with open-water fishery with respect to lake occupancy, while irrigation, fishery and domestic water supply do not have the same water salinity requirements. Salinity intrusion does not occur every year, but multi-year analysis on chloride levels revealed that its concentration exceeds the permissible level of 250 mg/l for drinking water with an average of seven months in a year (SDLBE, 2002). As the population and economic pressures in the basin's natural resources increase differences among water users will become increasingly serious. Competition fundamentally originates from the limitation of water quantity and quality. As a result, efficient allocation of water in terms of quality and quantity, through economic tools and approaches becomes the most important and crucial issue in the lake management.

With the economic uses and with the increasing scarcity of water resources, there are positive values attached to water.

A resource pricing study was undertaken to identify the actual users and thereafter estimate the raw water price in view of the rising water scarcity. Such an analysis is undertaken in the Laguna Lake, this being the only water resource in the country. The management of this resource is placed under the complete control and management of Laguna Lake Development Authority (LLDA). The LLDA has the mandate to charge a fee for the use of raw water for all beneficial uses.

The study confirmed that a number of sectors extract water from the lake and its tributaries for various consumptive and non-consumptive uses. The price of raw water derived for the various uses was practically based on rent estimation, opportunity costs and alternative uses. The costs of degradation and rehabilitation which include on-site and off-site impacts were not covered in this study. However, further studies must be undertaken to determine the true economic water price.

KEYWORDS: economic instruments, resource pricing, sustainable development