Water and the State of Water Resources in Davao City
 

GENESIS 9:5
                       :FOR  YOUR OWN  LIFEBLOOD, TOO, I WILL DEMAND AN ACCOUNTING; FROM EVERY ANIMAL I WILL DEMAND IT, AND FROM MAN IN REGARD TO HIS FELLOW MAN I WILL DEMAND AN ACCOUNTING FOR HUMAN LIFE.”
 

Definition of Terms

Aquifer - A saturated bed, formation, or group of formations which yields water in sufficient quantity to be of consequence as a source of supply.

Confined Aquifer - A water saturated bed, formation or a group of formations. In a well penetrating this aquifer, the water level will rise above the base of the upper confining formation. A semi-confied aquifer is an an aquifer in which the upper confining layer posses a certain degree of permeability to allow leakage.

Drawdown - The lowering of water level when pumping is in progress or when water is discharging from a flowing well.

Evapotraspiration - A collective term that includes water discharged to the atmorshpher, as a result of evaporation from the soil and surface-water bodies and, as a result of plant transpiration.

Permeability - is a measure of the ability to transmit water through its pores and openings when subjected to pressure or a difference in head. It is expressed in units of volume of water per unit time per cross-sectional area of material for a given hydraulic head.

Piezometric Level - The piezometric level refers to the imaginary sruface to which water rises in wells tapping artesian aquifers.

Pumping Level - The level in which water stands in a well when pumping is in progress.

Recharge - The amount of water which goes into the aquifer or a hydrologic system through rainfall, infiltration from rivers and irrigation systems and from adjacent regional aquifers.

Run-off - The amount of water which flows over the ground surface after rainfall net of the amount which infiltrated into the subsurface.
 

I.   INTRODUCTION

 Water is an indispensable commodity for human subsistence. Lack of water supply could pose great perils to man. 

 Fortunately, our city is endowed by nature with the second best source of water in the world.  However, this does not mean that our source of water will be just as abundant today than what it could become in the years to come. Recent studies made by various organizations show that there is a constant decrease and deterioration in our water resources. These studies posit that if we are not careful enough in maintaining the abundance of our water resources, we may suffer from lack of water in the future. These studies attribute the danger that may happen to our water resources to the abrupt population growth, to pollution from different factories and agricultural plantations, the insufficient implementation of laws protecting our water resources such as the watersheds, the illegal extraction of water which remains uncontrolled, and the lack of proper education to the people on how to safeguard our water resources. 

 The present situation does not yet reach the level of alarm. But, if we do not have a keen foresight of what may happen to our water resources, it may by then be too late for us to realize that we have failed to protect our water resources. Alas, we are now beginning to experience problems in our supply of water. As a matter of fact, the Davao City Water District is now planning to tap surface water to serve for our demands, instead of the much safer, ground water. And this could only mean that we have reached the initial stage towards the main problem, and that is, the possibility of experiencing scarcity in water. 

 This is the vital goal of the study, to create awareness of the present state of our water as well as our water resources. The laymen may not be aware of these facts, for all we know is that Davao City is rich in water. Yet, it may not be soon until we realize that Davao City’s abundance in water has become a myth. 
 

II.   STATEMENT OF THE PROBLEM:

 Davao City’s water resource is next to the most potable water in the world, which is Netherlands. However, recent studies reveal that our water resources in Davao City will soon reach the point of scarcity and deterioration of its quality. This is due to the following factors:

1) Unregulated water extraction;
2) Unregulated waste management;
3) Pollution from the plantations in the watershed areas; and
4) Unprotected as well as unpreserved watershed.

Notably, the Davao City Water District is on the verge of conceding to the studies and findings made by other agencies concerned such as the Asia-Geodyne and Philippines-Canada Environmental Management (PCEEM), University of the Philippines Minndanao Study Team Report, and Researches made by Ateneo de Davao University (ADDU) Chemistry Students. This may be proven by the fact that the Davao City Water District (DCWD) has envisioned in tapping surface water to supply the Dabawenyos’ demand.
 

III. SCOPE AND LIMITATIONS
:
 The study is limited only to the surface and ground water. Being the biggest out of the seven (7) watersheds of Davao City, the city is now extracting 97% of its water supply from Talomo-Lipadas watershed. Hence, the group is focusing its research to this area to prepare an overview of the existing underground water potentials and identify related potential environmental problems the soonest possible time. 
 

IV.   METHODOLOGY:

1.  The study also relies mainly on the data provided by the various   Government and private agencies.

2. The collection of data has been undertaken in the following manner:
a) Internet surfing and library research;
b) Interview with selected technical and legal authorities;
c) Office inquiry having competent expertise on water condition;
d) Investigative research on the different units of the government specializing on specific fields regarding the state of water resources in Davao City.

3. Assessment of the water quality in Davao City through the various information gathered from different sources.

4. Review of related literature, including Laws on Waters, Davao Water District Creation, functions, future direction, and company reports. 
 

V. THE ASIA GEODYNE STUDY

Davao City in the capital of Southern Mindanao and envision to be the premier socio-economic growth center for the whole of Mindanao.

To rationalize the planning and development of the city, with due consideration of the city’s groundwater and surface water potentials, (Davao Cityis extracting 97% of its water supply from groundwater) and overall availability of WATER RESOURCES in the light of the foreseen rapid urbanization and eco-tourism development, the city grovernment and DENR XI thru Metropolitan Environmental Improvement Program (METP-DENR) and World Bank, Commissioned a study of the city’s groundwater condition in June 1997.

To provide the legal basis for pursuing the vision of modern development of the city, a zoning ordinance for Davao City was enacted n 1996 in line with the Comprehensive Land Use Development of the City. Unfortunately, a comprehensive and updated baseline information on Water Resource potentials and related environmental issues was not fully available during the preparation of the said zoning ordinance. This study aims to prepare an overview of the existing water resources potentials and identify related potential environmental problems as a guide for policy-makers, land use planners and water resource developers. It also aims to characterize the ground water conditions and potentials based on an environmental approach for development.
The cooperating agencies that coordinated and directly contributed logistics and expertise to this study include both public and private industries.
 

CITY PROFILE

Geographical Location. Davao City is considered to be the largest city in the Far East. It is located alongNorthwest Shoreline of Davao Gulf between 6 deg.58’ to 78 deg.34’ North Latitude and 125 deg 14’ to 125 deg 40’ East Longitude. It is bound to the north and east by Davao del Norte Province, to the west by North Cotabato Province and to the Southwest by Davoa del Sur province.

Political Subdivision. Davao City is divided into three (3) congressional districts and further into eleven (11) administrative districts namelu: Davao City Proper, Agdao, Buhangin, Bunawan, Talomom Toril, Tugbok, Baguio, Calinan, Marilog and Paquibato.

Land Area and Land Calssification. Total land area of Davao City is 244,000 hectares representing approximately 8% of the total land area of Region XI. Alienable and disposable land compromises 39% of the total land area with the remaining areas classified as forest lands, timberlands and others.

Topography. A substantial part of the city is mountainous especially towards its north and western flanks with uneven distribution of lowlands and plateaus towards the southern coastal areas. The Western Mountain Ranges which delimit the boundary of Davao City with North Cotabato includes Mt. Apo and Mt. Talomo volcanic cones, the highest peaks in the Philippines. Mt. Apo also serves as the natural intersection point for the political boundaries of Davao City, Davao del Sur and North Cotabato. The entire city drains toward the Davao Gulf mainly through 2 rivers, the Davao River and the Talomo River.

Other Characteristics. Davao City is located outside of the typhoon belt, as such, weather and climatic conditions favor the production of almost all sorts of crops and agricultural products. Rainfall is near uniform distribution throughout the year.
 

DEMOGRAPHIC CHARACTERISTICS

 Population. The national population census establishes the population of Davao City slightly above one million persons in 1995. It is estimated that the population will reach 1,179,000 in the year 2000 and 1,584,000 in 2010. However, actual population based on the latest national census 2000 is 1,146,858 persons. The built-up areas are located on lowland plains in the eastern southeastern parts.

 EXISTING RESOURCES

 Land and Agricultural Resources. Davao City consists of agricultural areasgrassland and shrubland areas and other land resource areas with area coverage of 98,151 has. (40.2%), 89,329 has. (36.6%) and 7,366 has. Respectively. The agricultural areas have the biggest total land coverage. The grassland is also ised for cattle ranching and dairy purposes. In some districts, kaingin or slash and burn exists. Other land resources consistof urban lands, lakes, main river alluvial channels, wetlands and other creek/river escarpments.

 Forest Resources. Woodland or forestland/timberland is the 3rd biggest area with 43,147 has. (17.68%). A large forest-woodlands are lies within the core of Mt. Apo National Park and Mt. Talomo upper slopes which is declared as conservation forest zone “due to its biodiversity and wildlife characteristics. The forest covers still roughly define the original forest-watersheds of Davao River basin that also need protection, rehabilitation and management.

 Mineral Resources. Davao City has limestone deposits, guano and phosphate deposits, sand and gravel deposit in Davao, Lipadas, and Lasang Rivers and the unconsolidated pyroclastic and lahar deposits along the slopesof Mt. Apo and Mt. Talomo cones.

 Water Resources. Davao City haas a generally large water resource for domestic, irrigation,mini-hydropower and other agricultural needs and indicated as indicated by the near uniform distribution of rainfall and the presence of numerous creeks and rivers. Based on the classification of the Philippine River Babsins by the NWRB, the Davao and Lasang River Basins are considered as principal basins in Davao City. The drainage area of Davao River is about 48 sq. km. While Lasang River is 44 sq. km. Other important river basins for providing irrigation water are Talomo and Lipadas Basins.

 With respect to groundwater resource, Talomo District, Bunawan District and Tugbok District indicates the rpesence of potential aquifers as source for water supply. 97% of the domestic water supply in the City comes from groundwater.

 Private pumps, private wells and Level III piping system by the DCWD provide the bulk of the water supply for Davao City proper and vicinities that is pumped from groundwater. The Talomo River catchment has so far been the most promising groundwater source being tapped but theDCWD. Potable and “sweet mineral water” quality in Talomo plains flows thru artesian wells drilled 30-40 m deep from the surface. In comparison, the few wells and shallow pumps in Bunawan District have difficulty in supplying scarce groundwater, the water also having unsavory taste (hardwater). In remote areas, farmers depend on rainwater, spring and shallow dug wells (1-4m depth) mostly found along creekbeds for domestic water supply.

 Revised Zoning Ordinance of Davao City.  In 1996, Ordinance No. 4042 on land use rezoning was approved by the City Council to provide a legal basis for pursuing the vision of the City. The City objectives are environmentally guided to promote an ecologically-balanced development for Davao City.

 The land use zone types impact water resources as it gives priority to the protection of the requirement by requiring any development of the area to have a complete sanitary sewerage system with primary and secondary treatment facilities, as well as disposal disposal of such effluent being subject to the rules and regulations of the government agencies.

 Other environmentally planned use zones include the Forest Zone, Water Zzone, Protected Area, Eco-Tourism Zone, Agricultural Zone, Agricultural Zone, Agro-industrial Zone and other.
 Aside from the five proposed water disposal and landfill sites and commercial growth centers in Marilog, Toril, Bunawan,. Paquibato and Caliman have been identified in Davao City which may have impact on the groundwater resource in terms of sewage, solid waste and chemical effluents.
 Additionally, for land use regulation, the corresponding certification as to non-pollutive, pollutive or highly pollutive and further classified as non-hazardous, hazardous and extremely hazardous, shall first be secured from the Regional Of the regional office of the DENR

Geomorphology, Hydrogeology and Water Quality

Geomorphological Setting.  Davao City is included within the six catchments namely, Lasang, Bunawan, Davao, Talomo, Lipadas, and Sibulan catchments. It is also divided into six major terrain components namely: The Mt. Apo-Mt. Talomo Cones, Apo-Talomo Slopes, Davao River Channel, Coastal Area, Northern Sedimentary Hills and Northern  Sedimentary Mountains. The principal drainage system includes the Talomo, Lipadas and Sibulan Rivers.

Geological Setting. Davao City has seven major soil and rock formations. The northern section is essentially underlain by pyroclastics while the southern section is made up of sedimentary rocks.

Hydrogelogic Framework. Davao City has two hydrological systems namely the Talomo-Lipadas-Sibulan System and the Davao-Bunawan-Lasang System named after the catchments they represent.

Talomo-Lipadas-Sibulan System. Figure 3-6 shows a plot of the main Well Field contains the 35 production wells of DCWD. These wells tap the deeper, semi-confined section of the aquifer section. An undetermined number of privately-owned and shallow tube wells tap the upper unconfined aquifers from the upper slopes of Mt. Apo and Mt. Talomo down to the coastal section. The system is made up of multi-layered aquifers separated and/or capped by relatively impervious horizon.

Lasang-Bunawan-Davao System. This system is basically sedimentary in character. The primary aquifers of the system include unconsolidated sediments of Davao River (Figure 3-8)and the weathered and fractured sedimentary rocks and limestone beds in the Panacan Area. The limestone in the northern part of Davao River is a potential aquifer.

Unconsolidated Aquifer-Davao River. In 1982, LWU and C. Lotti explored the unconsolidated alluvial deposit within the Davao River. It confirmed the presence of at least 2 water-hearing layers within the river channel. The quality of water from the alluvial aquifers will be directly related to the quality of water of Davao River. The coastal section is expected to be susceptible to saline contamination. The Davao River Aquifer has already been tapped since the construction of the test wells in 1982. Recharge potential is very high or the sediments are presumably in hydraulic contact with the Davao River.

Sedimentary Aquifer-Panacan Area. The weathered and fracture sedimentary rocks in Panacan area serve as aquifers of two DCWD Wells and for a number of privately-owned wells. The principal aquifer consists of sandstones and limestones. Potential aquifers include the large limestones body upstream of the Davao River. Recharge comes from rains and from creeks draining the upper section of the sedimentary watershed.

Zones of GROUNDWATER Potential. Figure 3-10 shows the zones of groundwater potential with their potential ratings indicated as very low, low, medium and high. The HIGH zone would coincide with the triangular area with the apex at the Malagos-Calinan Area and the base extending from Talomo to Toril along the coast. It includes the slope section between the coast up to the overlapping layer of pyroclastics. The High Zone is characterized by the natural discharge of water through a line of springs near the coastal area and the concentration of production wells both DCWD and non-DCWD wells. Areas within the Davao River Channel would rate high in groundwater potential . Recharge is provided by the Davao River which is presumably connected to the identifiable water-bearing layers.
 

GROUNDWATER EXTRACTION AND PIEZOMETRIC LEVELS

Groundwater Extraction and Usage. The water supply system of Davao City comes from springs, surface water and groundwater through the wells. In 1981, water production (per C. Lotti Report) totaled to 29.6 Million Liters per day (MLD) from nine deepwells (27 MLD) and the operation of the surface source in Malagos (2.6 MLD). From 1981 to 1997, operational wells within the Talomo-Dumoy well field increased from 9 to 35. As of 1997, total production is about 156.7 MLD with contributions from 35 wells (154.9 MLD) and Malagos Creek (2.8 MLD). Production of 2 deepwells in Panacan is equivalent to 5.7 MLD. Actual well production for 1997 is about 138.2 MLD. These excludes privately-owned wells which likewise increased within the same period. (Note: Average daily production for 1998 and 1999 are 146.9 MLD and 155.7 MLD respectively from 41, 42 wells).

 Aside from the local residents of Davao City who source its water either from DCWD or non-DCWD wells and springs, major water users include industrial, commercial and recreational establishments like gold courses, soft drink plants, mineral water producers, and others.

Water Quality Assessments/Evaluation. The quality of groundwater produced from different wells in Davao City could be attributed to the combined effects of the nature of the hydrogeologic system and the character of the domestic, commercial/industrial and agricultural wastes discharges into the aquifer system. Basing on the National Standards for Drinking Water revised in 1994 to meet WHO standards (Table ___) DCWD water resources passed the physico-chemical standards over the reported monitoring period except for the consistent high chloride values and the hardness of the water yielded in some wells. On the biological front, the wells and springs monitored by DOH over the year 1996 and from January to July 1997 disclosed cases of pathogenic contamination at the city proper, Matina, Toril, Lasang, Panacan, Bunawan, Tugbok and Calinan.

Summary. The aquifers of Davao City belongs to 2 hydrological systems which are the Talomo-Lipadas-Sibulan and the Davao-Bunawan-Lasang System, named after the catchments they represent. The high zone coincides with the triangular area with the apex at the Malagos-Calinan area and the base extending from Talomo to Toril along the coast including the slope section between the coast up to Sibulan, Toril and Sirawan Areas. The main DCWD well field is located at the southeaster portion of this zone. Current groundwater production for Davao City is based on heavy extraction from DCWD well field located within a small portion of the High Groundwater Zone of Talomo-Lipadas-Sibulan Aquifer System. A total of 35 DCWD Wells in this field have a daily extraction rate of 134.6 MLD as of December 1997 (155.7 MLD in 1999). This is about 5 times more than the extraction rate of 27 MLD in 1981 or 16 years ago. Addition water is pumped from numerous non-DCWD wells, which were also sited within and around the well field. Within the period the 1981 to 1997-1998, a gradual but continuous decline in peizometric level has been observed in 15 out of 35 operating wells within the field. The most significant drops were registered by the wells located at the northeastern section of the field. This condition could be attributed to the increased groundwater extraction from a relatively small area of the well filed. 

 It must be noted that production sections of almost all DCWD wells are located below sea level. This position makes the aquifers susceptible to saline intrusion particularly if the observed decline in piezometric levels continue. The decline may eventually initiate salt water contamination  and pollution of the upper unconfined  aquifers and subsequently, the low aquifer system which supplies the water of Davao City. At this point however, the observed decline appears to have NO effect on the QUALITY of the water produced by the DCWD wells.

 The Panacan-Bunawa area is more susceptible to saline water intrusion due to the unfavorable landward dip of the sedimentary aquifer system. The catchment and recharge of this aquifer system is limited to effectively offset the anticipate increase in groundwater abstraction.

 The reported biological contamination of the wells in the upper section of the Talomo well field is indicative of the ease within which anthropogenic contamination could take place. Except for the sources at the city proper, the localities where the contamination was reported represent the recharge areas of the primary aquifer for Davao City.
 
 

Recommendations:

· Immediate review of available monitoring records of both DCWD and large non-DCWD production wells to establish correlation between decline in the piezometric level and increased number of wells and pumpage.

· construct observation wells to facilitate water level and quality monitoring;

· expand the list of parameters monitored to include those specified in the NSDW due to increasing agricultural and industrial usage of the primary recharge areas of the aquifer system;

· Conduct a detailed hydrogeologic study of the Talomo-Lipadas-Sibulan Aquifer system to establish the safe yield, regulate additional drilling and excessive pumping from the aquifer system

· strict protection of the critical recharge areas of the aquifer system and 

· explore and develop additional groundwater and new surface water sources in Talomo, Lipadas and Davao River Basins.
 
 

WATER BALANCE ANALYSIS AND SUPPLY-DEMAND ASSESSMENT

 Davao City has seven catchments or river basins namely:

1.  Lasang River Basins
2.  Bunawan River B
3.  Davao River Basins
4.  Matina River Basins
5.  Talomo River Basins
6.  Lipadas River Basins
7.  Sibulan River Basins

The Lasang and Sibulan River Basins were not considered in the water balance computations because while their upper catchments are within Davao City, they are discharging into Davao del Norte and Davao del Sur respectively.

 The Davao River Basin and Matina River Basin (sub-basin of Davao River Basin) has the largest catchment area of about 1,647 square kilometers, Bunawan River with an area of 65.5 sq. kms. is the smallest catchment. The catchment area of the Lipadas River Basins and Talomo River Basins are 170 and 120 sq. kms. respectively.

Utilization. The groundwater production of the DCWD constitutes the major portion of the groundwater utilization. The DCWD basically supplies the water requirements of domestic users or households, commercial/small scale industries and institutional establishments. Of the total groundwater production, about 92.5% (in 1997) in derived from the Dumoy well field in the Talomo River Basin. The only surface water production comes from Malagos System in the Talomo River Basin. In addition to the DCWD production, the groundwater is utilized for domestic use of population not being served by  DCWD system. Surface water utilization was assumed to be mainly for agricultural purposes. There are no data on the actual surface water use.

Water Demand Projections. The total water demand consists of demands from domestic, commercial and small scale industrial establishments, institutional, large industrial and agro-industrial estates, agricultural and other users (golf courses and softdrink companies). The national population census establishes the population for Years 2000 and 2020 are 1,178,580 (actual is 1,148,858( and 1,583,913 respectively. The DCWD average day demand projections for 1997. 2000 and 2010 were 144.1, 199.6 and 307.5 MLD respectively. 

Water Supply/Water Use and Demand Assessment.  The water balance analysis (i.e., the estimated surface water and groundwater use in River Basins are compared to the calculated surface run-off and groundwater recharge) of the Bunawan, Davao/Matina, and Talomo-Lipadas River Basins showed that the total groundwater recharge is about 781.7 MLD and surface run-off is around 8170.5 MLD. The estimated groundwater utilization as of 1997 in the basins is 146.8 MLD and the surface water use of DCWD and the estimated agricultural demand amounts to 1171.1 MLD. It can therefore. Be concluded that there is AVAILABLE WATER SUPPLY OR RESOURCES (groundwater recharged and surface run-off) to satisfy the present utilization of water.

 The present groundwater withdrawal in the Talomo-Lipadas River Basins of 138.6 MLD (mainly due to Dumoy well field) might be approaching the groundwater safe yield of the basis since this is already about 49% of the estimated groundwater recharge of the basin. Based on the ratio of the water use to available water supply, it is seen that the Talomo-Lipadas River Basins that has the greatest stress on its water resources especially groundwater. With the groundwater withdrawal reaching half of the calculated recharge, signs of irreversible lowering of piezometric levels and the formation of depression comes in the dumoy well field are being observed. Close monitoring of the piezometric water levels and extraction rates of DCWD and private wells at the main well field should be implemented to determine whether groundwater mining is now actually occurring or not in the area particularly the well field sections of Ulas to Bago Aplaya in Talomo District. It is however estimated that in 2010, if the sectoral demands continue to be satisfied through groundwater abstraction, the groundwater withdrawals would then exceed the recharge. In the long-term, the increased utilization of surface water particularly Davao River should be considered to satisfy the projected demands especially for water-intensive industrial/commercial/recreational establishments. This available surface water resource (as Davao River) is almost 3 times the present demand for water supply for Davao City as of 1997. In this regard, Protection of the Watershed of Davao River Basin is also important. 
 

ENVIRONMENTAL CONCERNS/ISSUES OF GROUNDWATER PROTECTION 

* The concern here is the strict protection from man made pollutive sources of the immediate recharge or entry points of rain/surface water as they flow and infiltrate towards the shallow water table and the semi-confined or confined deep aquifers (Figure 5-1). It is also obvious that the quality and sustainability of surface water (run-off) recharge at the headwaters of rivers and streams shall likewise benefit from having a groundwater recharge protection zone; 

* The Malagos Watershed’s (238 hectares, declared protected and managed by the  Davao City Water District {DCWD}) surface water which being is tapped as water supply by the DCWD should likewise be protected from contamination from adjacent irrigated agricultural lands that are potential sources of pesticides, herbicides and chemicals. There is a High to Medium Potential Groundwater Resource in Malagos Area that may also be tapped for water supply by the DCWD.

* Based on existing Irrigation and Water Supply (wellfield) map (Figure 5-3), bulk of the irrigation service areas are located within the agricultural lands in Tugbok, Calinan, Matina, Talomo and Bunawan Districts. This irrigation areas should be considered as potential sources of chemical pollutants that threaten the shallow water table below the service areas.

* The major water supply wellfield in Talomo-Dumoy area is adjacent to existing irrigation service areas (Better Living and Lubogan); the shallow groundwater flowing from these service areas may potentially threaten the wellfield in terms of chemical pollution;

* In a similar setting, the Malagos Watershed of DCWD is downslope from the Wangan service area which threatens both the surface water and shallow water table from chemical pollution;

* Based on existing location of similarly irrigated golf courses in Davao City, the Mt. Apo Golf Course in Talomo is a potential source of chemical pollution of the shallow groundwater that also poses a threat to the existing DCWD water supply wellfield in Dumoy-Talomo area. Baseline water quality sampling and monitoring is therefore needed in this regard.

* Based on the 1996-2021 Land Use Zoning Map of Davao City the existing Utility Map and the existing Water Supply Wellfield Map, several other point sources that can pollute the shallow groundwater as well as potentially threaten the deep aquifer have been identified such as the (a) proposed growth areas/residential expansion zones from Davao City Proper to Toril extending to Tugbok and Calinan Districts as well as in Marilog Proper and Bunawan Proper; (b) proposed Alambre waste disposal site which is just upstream from the water supply-wellfield area of DCWD and the existing dumpsite in Matina Pangi; (c ) proposed light-medium and heavy industrial zones, existing industrial plants and mining companies, existing and proposed golf courses/resorts, proposed planned unit development or eco-tourism zones, existing & future water-based industries and major waste users (e.g. Pepsi Cola, Coca Cola, Cosmos Bottling Plants and the Mineral Water Bottling plant). It should be emphasized that these industries may not be actually discharging pollutive wastes and chemicals due to their existing waste water, solidwaste and effluent treatment and disposal facilities at present. These industries, however, as the identified potential sources of pollutants, have to be regularly monitored. Future projects, nevertheless, now have to go through the new environmental regulations of the government, wherein waste water protection and sustainability is given priority in the EIA guidelines; 

* The improper siting of wells along the coastal areas and beside the DCWD wells, and uncontrolled or overpumping of wells that may cause the reversal of the hydraulic gradient inland from the sea and may induce seepage of seawater into the unconfined aquifer, thereby causing contamination of fresh water by saline water;
 

VI.  STUDY CONDUCTED BY THE ATENEO DE DAVAO UNIVERSITY (CHEMISTRY STUDENTS)

LASANG RIVER

        In a study made by the Ateneo de Davao University, results of the three month (October, November, and December 2000) monitoring of selected parameters on the water samples from the critical sites of Lasang river were obtained.      Based on the results gathered in said study, the following findings are established:

          The nitrate levels of the Lasang River were at a high of 0.9999 and 0.6213 mg/L for Stations #2 and #3, respectively.  These values are still within the limit set by the DENR in Administrative Order No. 34 for Class B waters  at 10.00 mg/L. The phosphate level of Station #2  has its highest value at 0.1799 mg/L while at Station #3 it was at 0.1732 mg/L.  These values are again within the DENR limit which has been set at 0.20 mg/L.  The pH (mean values at 7.99 +/- 0.01 for Station #2 and 8.24 +/- 0.01 for Station #3) and temperature values are still within the standards set by the Department of Environment and Natural Resources (maximum of 8.50 for  pH and no more than 3 degrees C rise for the temperature).  The lead level of the said Stations though went beyond the DENR limit at some sampling dates.  On the 5th sampling dates, Station #2’s lead concentration was at 0.10 mg/L which is beyond the 0.05 mg/L limit.  Station #3 also registered readings greater than 0.05 mg/L on the 4th, 5th, and 6th sampling dates at 0.06, 0.06, and 0.22 mg/L, respectively.

            The study recommends the following: 
a) other sampling stations of Lasang River be studied and monitored as well;

b) a more efficient method of nitrate determination  should be established for future use in parallel studies;
c) monitoring and analysis of the same parameters  on the Lasang River made on a regular basis to preserve and safeguard the present condition of the said river; and
d) more trials be made for  each analysis to obtain more reliable results.

ILANG RIVER

        A reaearch made by the Ateneo de Davao University consists of three months monitoring of selected parameters on the water samples from the critical sites of Ilang River.  It was conducted for the establishment of the baseline profile of the Ilang River for the Kinaiyahan Foundation Inc. The Ilang River is located at Barangay Ilang, Davao City.  It is classified by the EMB-DENR on August 10, 1998 as a Class C based on the standards of the DENR Administrative Order No. 43.  The beneficial usage of the river is for fishing, for the propagation and growth of fish and aquatic resources, recreation water class II (boating, etc.), and industrial water supply class I (for manufacturing processes after treatment).

         The evaluation and monitoring of the Ilang River revealed that the temperature is still within the standard set by the DENR for Class C river.  The average pH of the first sampling station was 8.40 and that of the second station was 8.45.  These values are still within the range (6.50-8.50) set by the DENR for Class C river; however, it is already in the official level.  The pH of the first sampling station on October 11 and December 18 were 8.57 and 8.58, respectively. These values exceeded the maximum level of 8.50.   On the other hand, the second sampling station on the same dates has the same reading of 8.61 and 8.57; they were also beyond the maximum value of 8.50.  The readings on the level of lead on November 21 and December 18, 2000 in the area below the Ilang Bridge were 0.12 and 0.42 mg/L which exceeded the limit of 0.05 mg/L for a Class C river.  On the other hand, on December 5 and 18, 2000 in the area near the new DUCC pumphouse, the level of lead also exceeded the maximum limit of 0.05 mg/L.  The level of nitrate is still within the standard set by the DENR for Class C river, which is 10.00 mg/L.  The highest reading obtained for the first sampling station was on November 21 which was 1.0873 mg/L while the second sampling station has 1.1025 mg/L on December 5, 2000.  However, the level of phosphate on almost all the sampling dates on both sampling stations are no longer within the standard set by the DENR for Class C river based on DENR Administrative Order No. 34 except on October 11 and December 18, 2000.  The highest value obtained for the first sampling station was 0.6454 mg/L on November 21 and 0.5864 mg/L on October 24, 2000 for the second sampling station 

           The following are recommended: 

a) The river must be closely monitored at a regular basis to safeguard the quality of the river;
b) More sampling stations as well as outer parameters should be closely monitored so as to obtain a complete picture of the profile of the water; and
c) Other method of analysis that is more efficient must be used in the determination of nitrate concentration. 

TALOMO RIVER

      A study conducted by the Ateneo de Davao University deals with the three-month monitoring of selected parameters on the water sample from the critical sites Talomo River.  Results of the study revealed that the level of nitrate, pH, and temperature of the water samples are still within the DENR standards for Class B water from October to December 2000.  However, critical values for pH were obtained.  The maximum limit set by the DENR was 8.5 and the highest value recorded was 8.38.  With respect to the water temperature, the highest value recorded (27.7 degree C) was less than the value (29 degree C) obtained by the EMB-DENR in their initial monitoring of the river as this is the basis if there is a 3-degree C rise,  for  the  DENR limits  a 3-degree C maximum rise in the temperature of Class B water.  The highest nitrate concentration recorded was only 0.9039 mg/L; it is far from the standard of 10.00 mg/L.  On the other hand, phosphate concentration during the third sampling (0.2632 mg/L for station 1 and 0.2310 mg/L for station 2) exceeded the limit of the DENR standard (0.2000 mg/L) as well as the lead concentration during the fourth (0.06 and 0.10 mg/L for station 1 and 2 respectively) and sixth sampling dates (0.30 mg/L for station 1 and 0.18 mg/L for station 2).  The limit set by the DENR for the lead concentration of Class B water is 0.05 mg/L. It was recommended that more sampling sites must be studied and other parameters should also be examined to obtain a complete picture of the river water profile.

LIPADAS RIVER

        In a Water Quality Assessment Report made by the Environmental Management Bureau in Davao City of the Lipadas River situated in Toril, Davao City during the six (6) months monitoring of the river (July-December 2000), the following classifications are reported:

      Class AA (Mt. Apo National Park to Brgy. Baracayo );

a) Class A (Brgy. Baracayo to Brgy. Bangkas);
b) Class B Midstream (Brgy. Bangkas to Brgy. Alambre); and
c) Class B Downstream (Brogue Alambre to confluence with Davao Gulf).

        The sampling was made quarterly.  The Stations were identified as follows:

a) Station 1 – At the mouth of the river;
b) Station 2 – At the foot of Lipadas Bridge;
c) Station 3 – At the foot of Piedad Bridge;
d) Station 4 – At the foot of Cam & Co. Bridge; and
e) Station 5 – 20 meters upstream of Cam & Co. Bridge.

        It was found out that the average values for color, temperature, pH, dissolved oxygen (DO), Biochemical Oxygen Demand (BOD) and Total Suspended Solids are within the standard for Class C water.  Hence, the water quality of the river conforms to its present classification.

        To maintain or improve the water quality of the river, the following are recommended:

a) plant trees along the riverbank to prevent soil erosion;
b) agricultural activities that tend to destroy the soil must be discouraged;
c) proper quarrying procedure should be imposed; and 
d) proper solid waste management.

DAVAO RIVER

The same study is done to Davao River located in Davao City.   Stations 1 to 4 are classified as Class B.  Whereas, Stations 5 to 8 as Class A.

        The stations were identified as follows:

a)   Station    1 –   mouth of the river;
b) Station 2 – below the Bolton  Bridge;
c) Station 3 – below the Bankerohan Bridge; 
d) Station 4 – Davao River diversion Bridge Ma-a;
e) Station 5 – Davao River at Mandug Area;
f) Station 6 – 800 meters downstream from the confluence with Tamugan River;
g) Station 7 – Tamugan River approximately 50 meters upstream from the confluence with Davao River; and
h) Station 8 – 50 meters upstream from the confluence with Tamugan River.

         The average values for color, temperature, pH, Dissolved Oxygen (DO), and Biochemical Oxygen Demand (BOD) are all within the DENR standard except for Total Suspended Solids (TSS).  TSS concentration exceeded the standard for Class A and B waters except at Station 2. 

        The water quality of the River still conforms to its present classification except that at present it does not meet the TSS level required for classifications. The study recommended that pesticide analysis should be included because of the banana plantation located nearby.  Also, monitoring should be continued in order to determine the trend and water quality of the river.
 

VII.   DAVAO  RIVER CONSERVATION PROJECT:  U.P. MINDANAO STUDY TEAM REPORT

 Aside from being renowned as the largest city area in the world, Davao City is also identified significantly through the Davao River. It is a large body of water where its watershed area is estimated to be 171,811.5 hectares, which flows into the Davao Gulf. Its grand channels and majestic streams have been useful to the lives of Davaowenyos, may it be livelihood, tourism, or for transport. 

 Yet, as can be visibly seen by any motorist, who crosses Davao river through the Diversion bridge, the Generoso bridge, and the Bolton bridge, the Davao river is not really one’s idea of what a river should ideally be. The technological advancement, massive industrialization, over population, improper waste management, among others contribute to  Davao river’s unpleasant image. Its mad brown color during rainy seasons and dark green color during sunny days show that the river is not in its best health. The profusion of squatter shanties along the river banks in Ma-a, Bankerohan, and Bucana with their toilets constructed right above the river if not above the canal that directly spews its waters into the river gives another picture of what the river waters are carrying off into the Davao Gulf.

 This alarming scenario called for preservation programs and conservation projects both from government and private agencies. One of those programs is the Davao River Conservation Project conducted by the UP Mindanao Study Team Report.

 The objectives of the research are the following:

1) To save Davao River from further deterioration;
2) To enhance its aesthetic value;
3) To instill public awareness that the said river is not a mere ordinary way that conveys flood water from the inlands per se but should be viewed also as a natural asset of Davao City in furthering its development.

The following are the breakdown of topics of the report:

1)Socio-economic aspects
2)Land use patterns and analysis
 a)Talomo
 b)Buhangin
 c)Tugbok
 d)Calinan
 e)Marilog

The Davao River Conservation Project-UP Mindanao Study Team Report had attached as part of  its annexes, the vision statement of the Davao  River Integrated Development  Concept, which says:

“WE ENVISION DAVAO RIVER AS AN IMPORTANT WATERWAY FOR TRANSPORT AND TOURISM.  IT IS NAVIGABLE BY FERRY BOATS, FLOATING RESTAURANTS, FISHING VESSELS AND OTHER RIVER CRAFTS.  BOTH ITS BANKS HAVE CONCRETE DIKES WITH WELL- LIGHTED TREE-LINED PROMENADES AND ROADS.  THERE ARE MORE BRIDGES THAT SPAN IT FROM WAAN TO THE RIVER DELTA AND INTER-CONNECTS WITH THE COASTAL ROAD.  DAVAWENYOS AND TOURISTS ALIKE ENJOY FLUVIAL FESTIVALS AND AQUASPORT SPECTACLES IN IT.”

It also cited a concept paper on the Davao River Integrated Development Concept which envisioned the D.R.I. D. Plan as not just a man’s dream.  It is a long range Development Plan that has gotten favorable indorsements from the City Development Council (CDC Res. 183 series of 1991) and the Legislative Council (SP Res. series of 1993). It now forms part of Davao City Comprehensive Development Plan and is now ready for further studies and possible local and/or foreign funding.

The Department of Environment and Natural Resources (DENR) assessed the water quality of the Davao River.  The physico-chemical parameters that were considered to present the quality of river water to present the quality of river water include the:

 1)Temperature
 2)PH
 3)Dissolved oxygen
 4)turbidity
 5)total suspended solids and metals

As there was then lack of specific laboratory equipment-DENR was not able to  include in their measures the bacterial presence along the river sampling stations.  The findings they have come up with were considered to be representatives results on the conditions river body, based on the sampling stations.
 

VIII.   CONCLUSION

 It may be easily argued that at present there is no shortage of water.  However, the increase in population, agricultural activities, and industrialization may have a negative effect on the water quality. The change in water quality could put pressure in investing in water treatment facilities.
 In order to reduce the risks of having the shortage to occur sooner rather than later, it is imperative that the water resources be managed with  special attention  and of extremely  importance.

. Water conservation and protection programs must be implemented in order to save both the quality and the quantity of the water supply in Davao City. 
 

IX. EVALUATION

           The findings of various studies differ from one another except for a single fact, and that is, there is a danger of having a scarcity of water supply.   The studies conducted by Asia-Geodyne is based on the law of supply and demand. The demand for water for the past ten years has more than doubled. This was mainly due to the rapid population growth. The increasing number in population results to a greater demand for water consumption. The supply of water on the other hand, does not multiply rapidly to cater the greater demand. Hence, this results into the shortage of water supply. The Asia-Geodyne predicts that there will be shortage of water by thew year 2010, and by then we could only use surface water as our supply. But, tha use of surface water is highly discouraged. 

            Studies made by U.P. Study Team and Ateneo Chemistry Students reveal that our surface water, such as Davao river,  Talomo river, Ilang river, Lasang river, and Lipadas river, is not as safe as our ground water. Although our rivers arer not declared biologically dead, or as polluted as Pasig river, it is still not safe for human consumption. The studies show that there is a considerable amount of nitrates and pesticides, harmful bacteria, and some other chemicals and wastes, that if taken internally, would cause harmful effects to man. In fact, our beaches in which the Davao river ends was declared as unsafe for human contact, hence, Davao river itself is polluted. The pollution to our surface water has been caused by, as pointed out by Philippines-Canada Environmental and Economic Management (PCEEM) Project, non-existing sewerage system for our city. Domestic waste water goes directly into the storm drainage system, which discharges into the rivers. Davao city households still practices the predominant method of “throw and burn.” Another reason pointed out by PCEEM is the population growth which causes the production of more wastes eventually disposed in our rivers. Another cause is the chemical and pesticides within the river areas made by agricultural plantations. Therefore, it is entirely impossible to tap surface water to serve the city’s demand. Thus, there is no other way but to use ground water, which we ought to preserve and maintain.

 The PCEEM is a group requested by the Philippine government to manage our watersheds. The group claimed that there is enough water, but there is improper management to maintain our water resources. The causes it pointed out are the rapid population growth, the improper disposal by households of their wastes. 

 On the other,  the Davao  City Water District, is firm on its stand that there is enough water for everyone, and that there is not much problem in the quality and quantity of our water supply, although it admitted that it is planning to tap surface water as supplementary to the ground water. This group could only conclude from such admittance that there is an impending problem, and the truth is, DCWD is afraid to admit it for whatever reasons only they would know. 
 

X.    RECOMMENDATION:

 There is an urgent need to protect, conserve, manage and develop the city’s water resources and to regulate the manner and extent of their use and utilization to ensure adequate and clean water supply for its present generation and the generations to come.

 During the past few years, the following have posed a real danger to the quality and quantity of the city’s water resources:

a) Rampant and indiscriminate drilling of wells in Davao City by industries that draw undetermined volume of water from its aquifers;
b) Unregulated constructions of industrial plants, housing subdivisions, and memorial parks in critical areas like aquifers exposing them to contamination from chemicals and human wastes;
c) The lack of consistent solid waste disposal system;
d) Relentless and unabated destruction of water shed.

Hence, the group has formulated the following approaches in the light of conserving the state of water resources in Davao City:

1. There should be a review on the principle of effective management.  The basic principle on management involve PLANNING, ORGANIZING, STAFFING, LEADING, and CONTROLLING.

  PLANNING is important in the sense that there should be a firm community based management concerning the short term and long term plans for sustainable development centered on the conservation of water resources.

 ORGANIZING entails collaborative and integrative management effectiveness as regards the regular evaluation and assessment of reports on the condition of the water resources and take effective measures highly responsive thereto.

 STAFFING signifies capacity building wherein the duties and tasks as well as the accountability of the various government units are clearly defined and limited so that there will be no encroachment of authority as regards the concept of water preservation.

 LEADING means there should be an awareness campaign in order to apprise the people of the need to protect and conserve water resources.  An effective communication between the people and the local authorities will remove barriers in obtaining information for purposes of identifying entities violating the laws on water conservation.

 CONTROLLING involves the authority of the local units to command and control the use of water resources in a proper manner. Short term and long term plans must be compared with the actual results in order to make modifications and revisions in the plans for the protection of water resources.

 Thus, there should be decentralization of duties and responsibilities wherein the local units will be tasked to take effective measures and implement the existing laws on water because they have the competence and knowledge on the geographical protected areas but with the supervision of lawful authorities.  Empowerment of the local units must be given due course in recognizing the basic principle that water forms part of the natural wealth and patrimony of the state.
2. There should be a centralized data bank wherein evaluation and assessment reports from the various government units will be collated and compiled in order to have an overall and thorough evaluation for purposes of determining the factors which need to be enhanced and improved.
3. Tap immediate local agencies with competent expertise and consider their views and suggestions on the protection of water resources.
4. Organize laboratory consortiums in order to establish baseline data of water characteristics and undertake the assessment of the condition and quality of water.  It is imperative that there should be enough equipment for laboratory works.
5. Construction of observation wells to facilitate the monitoring of water levels and the impact of improper waste disposal.
6. Immediate review of the available monitoring records of Davao City Water District (DCWD) production wells to establish correlation between the decline and increase in the number of wells and pumpage and to validate current assessment. 
7. Groundwater quality monitoring of the existing DCWD and non-DCWD production wells through the recommended observation wells. 
8. Exploration and development of groundwater expansion area (towards Toril and the Davao River alluvial plain) and new surface waters in the Talomo, Lipadas, and Davao river banks.
9. Monitoring should be continued to establish a trend in the water quality of the DAVAO RIVER.  Data gathered in the monitoring could be used as a basis for the formulation of policy relevant to the protection and preservation of the river.
10. Quarrying activities should be minimized or proper procedure in quarrying should be observed to minimize the occurrence of suspended solids.
11. Limitation of plantation near water sources. Pesticide analysis should be included in the monitoring because of the plantation located nearby.
12. Prohibition of illegal occupants near the water sheds.
13. Reforestation.  Tree planting must be undertaken.  It should not be put into oblivion that trees hold water in its holistic nature.
 

Avila, Anatolio Jr.
Coda, Monalisa B.
Dela Rosa, Leah
Lamparas,Ariel
Liza, Connie
Nuesca, Rocarma
Opalla, Marcelo VII
Sator, Harold