PHYSICAL CHARACTERISTICS

Topography, Slope and Elevation

Pateros is a low-lying area. It is only about 2.0 meters above sea level with its highest elevation at about 4.0 meters above sea level. Its almost sea level elevation has caused perennial flooding in most of the municipality. High tide in Laguna Bay, which causes backflow of seawater from the Manila Bay into the Pasig River up to Pateros River, coupled with heavy rains, have caused floods in the low-lying areas of Pateros.

The whole municipality is almost of flat terrain with slope rising only up to 2.5% slanting downward towards Laguna Lake. Such terrain and slope makes Pateros very suitable for urban development.

Geology and Geomorphology

• Rock Formation

The geology of Pateros is made of quaternary deposits, specifically alluvium (Qal) in the eastern portion and clastic rocks (Qc) in the western area.

Alluvial deposits are characterized by unconsolidated mixture of sand, gravel, and considerable silt and clay derived chiefly from the weathering of pyroclastic and volcanic rocks. They generally occupy the extensive coastal and floodplains around Laguna de Bay. These include recent river deposits covering the older rocks on flat lowlands but exclude the residual soil in extended plains and cultivated uplands.

Clastic rocks are composed principally of tuffaceous sedimentary detritus, which includes waterlaid and reworked sandy tuffs. They are generally bedded and well stratified and are found in places intercolated with thin beds of fine tuff. The major portion of the area west of Laguna Lake, particularly from Pateros to Los Baños, is made up of interbedded tuff, marine sediments and volcanic ash, known as "Laguna Formation" or Guadalupe Tuff. This rock formation is considered very important because of its good water-bearing characteristics.

The rock formation is significant in determining groundwater supply but does not have any bearing on flooding since the major factors affecting flooding are the elevation of the area and of the existing water bodies.

• Fault Lines

Pateros is within the Marikina Valley Fault System. The West Marikina Valley Fault which moves down from Marikina to Calamba crosses Pateros from the northeast down to southwest, hitting Barangays Sto. Rosario-Kanluran, Sto. Rosario-Silangan, Magtanggol, Sta. Ana, San Roque, and Martirez. The path of the fault line nearly follows the division of the two geologic characteristics of the municipality.

The MVFS is a newly classified active fault based on a recent mapping and trenching work conducted by Punongbayan and others (1990). It is a potential earthquake source located only 5 kilometers east of the center of Metro Manila. The fault strikes nearly north-south extending from the eastern end of Tagaytay Ridge to as far north as the boundary of Rizal and Bulacan provinces. The fault skirts along the western shore of Laguna Lake and cuts through the Pasig-Marikina River Junction with a local vertical displacement of at least 70 meters. Historical earthquakes is difficult to correlate with the activity of the MVFS because of limited available data but the possibility that this structure could have generated some of the past earthquakes cannot be totally ruled out.

Other fault lines and trench that are assessed to significantly impact Metro Manila are the Philippine Fault Zone (PFZ), the Lubang Fault, Casiguran Fault, and the Manila Trench. The presence of the MVFS that cuts through Pateros and the other potential earthquake sources make the municipality critical with respect to man-made structures.

Soils

• Soil Types

There are two major soil types identified in Pateros. These are the Guadalupe and Marikina Series. These soil series are characterized in terms of surface texture, slope, soil erosion, and flooding hazard. The soil types in Pateros are represented as about GdBAOI and MkHA, for Guadalupe and Marikina series, respectively.

The Guadalupe series is one of the soils of the plains. This series is underlain by volcanic tuff of varying degrees of disintegrated weathering. The surface soil is very dark brown to nearly black plastic clay. When dry, it has coarse, granular to cloddy structure. The subsoil is lighter in color than the surface soil. Spherical tuffoceous concretions are present in both the surface soil and the subsoil. Limestone concretions are also in some areas. This type of soil is utilized mostly for lowland rice, corn, and root crops.

The Marikina series is a typical recent alluvial soil. The surface soil is medium or light brown in color. Just below the surface soil is a horizon of very dark brown to dark gray in color, a little heavier in texture than the surface soil. This is the most distinguishing characteristic of the Marikina series. A tuffaceous material in varying degrees of weathering and disintegration underlies the substratum of this series. The presence of a dark-colored horizon in the subsoil is indicative of good drainage. The Marikina soil occupies all of Marikina Valley from Montalban to Pateros. The soil being light in texture loses moisture easily. Soil of a heavier texture is located on the west of the fault line. There are three types of this series: loam, clay loam, and silt loam. Its good external and internal drainage makes this soil type suitable mostly to rice, corn and sugar cane, some fruit trees and bamboo along rivers.

These two soil types of Pateros are suitable for cultivation and had been the reason for the predominantly agrarian economy of Pateros during the past decades.

• Soil Suitability

Soil suitability for some specific use is based on certain criteria, according to the use under consideration. A soil suitability analysis indicated that Pateros is equally suitable for urban use, for diversified crops, for tree crops, and for rice. As part of highly urbanized Metropolitan Manila, the whole of Pateros can be considered highly appropriate for urban use.

• Soil Erosion

Erosion is the process by which soil particles are removed and transported by run-off water and/or air. Its degree and occurrence depend on several factors such as the degree and length of slope, intensity and distribution of rainfall, vegetative cover and land use, and physical characteristics and profile. The degree of erosion in any area varies from slight to very severe depending on the amount of topsoil and subsoil removed and the presence of gully formation. Being almost flat, Pateros does not possess any erosion potential.

Drainage and Hydrology

Drainage refers to the frequency and duration when soil is free of saturation. It is a factor that requires critical consideration in evaluating soil suitability since it invariably affects land utilization.

Pateros is within the Laguna Lake Basin. The whole Laguna Lake basin is drained by various rivers: Marikina, Taguig, Angono, and Napindan Rivers in Rizal; San Juan, San Pedro, and San Cristobal rivers in Laguna while Pasig River serves as the gateway of Laguna Lake on the east Manila Bay on the west drains the Laguna Lake via the Napindan River.

The Pateros River, a tributary of Pasig River mainly drains Pateros. This river runs from Barangay Sto. Rosario (K) to Barangay Aguho on the western side of the town. Being linked to the Pasig River, the flow and direction of Pateros River is dictated by -
the elevation of the lake water surface at the Pasig-Napindan-Marikina junction,
the tide elevation in the Manila Bay, and
the elevation of the lake surface of Laguna.

Pateros drainage is governed by the behavior of the bodies of water mentioned. Aside from Pateros River, the municipality is drained by a number of creeks. The other two major waterways are the Sta. Ana River and Sto. Rosario River. Creeks include Panday Creek and Napindan Creek.

Being a flat and low-lying area and the way the natural drainage pattern has been disrupted by riverbed siltation and obstruction of waterways, the town has been subjected to recurring yearly floods, especially in the areas near the Pateros River and the creeks.

Meteorology

There is no weather gauge in Pateros. The nearest gauge is located at the Ninoy Aquino International Airport (NAIA), thus the records taken from this station are used in analyzing the climate of Pateros.

• General Climatic Type

Pateros falls under climatic Type I of the Modified Corona's Classification of Philippine Climates. This is characterized by a relatively dry season from January to April and wet during the rest of the year.

• Rainfall

The rains start during the month of May, reaching its peak on July, August, and September, through November. The annual rainfall from 1961 to 1995 is 1,849.3 mm with an average of 113 raining days per year. This is slightly lower than the 1951-1970 average of 1,933.7 mm with 143 raining days per year. This can be explained by the El Niño phenomenon in the mid-eighties.

• Temperature

The mean temperature in Pateros is 27.45ºC. The average minimum temperature is 23.2ºC while the average maximum temperature is 31.7ºC. The low temperatures are recorded starting December through February. The temperatures slowly increase and reach their peak in May during the summer months. The average temperatures of 1961-1995 given above are slightly higher than the 1951-1970 averages of 26.6ºC mean, 22.2ºC minimum, and 31.0ºC maximum temperatures. This indicates the slowly increasing average temperature of the area through the years.

• Relative Humidity

Relative humidity is the ratio of the amount of water vapor actually present in the air (g/m3) to the maximum possible density of vapor in the air (g/m3) at the same temperature. The average humidity in Pateros in 1961-1995 is 75%, slightly lower than the 1951-1970 average of 78%. The highest humidity is recorded during the rainy months of June to November through December.

• Prevailing Winds

The predominant winds that pass over Pateros are the Northeast and Southeast monsoon. Eastern winds predominate over the municipality most of the year, from October to May, June to September experiences the western winds. The average wind speed is 3 miles per second (mps).

NATURAL RESOURCES

Water Resources

• Surface Waters

The surface water of Pateros consists of Pateros River and its tributaries, Sta. Ana and Sto. Rosario Rivers. The surface waters of Pateros are all in very poor state. They are polluted and silted. River pollution mainly comes from sewage and solid wastes. Solid wastes and particles that flow with stormwater runoff cause siltation. Siltation results to lower volume capacity of a waterway since the materials settling at the bottom of the river occupy space. This causes overflowing of rivers during heavy downpour.

Aside from pollution and siltation, the Sta. Ana and Sto. Rosario Rivers are encroached by residences. This changes its effective width at various points. The encroachment of these rivers increases its pollution with sanitary sewage and solid wastes from the households.

The Pateros River, being a direct tributary of Pasig River, is included in the Pasig River Rehabilitation Program (PRRP). Among the key activities of the PRRP, programs that are to be implemented on the Pateros River is the resettlement of illegal settlers and embankment protection.

• Groundwater

Based on the groundwater assessment (by Ingledow and Associates), groundwater development potential of Pateros is rated medium. The quality of the water derived from the numerous willow and deep wells in Pateros are found unfit for human consumption. From the CDM report "Groundwater in the MWSS Service Area" in May 1976, specific samples taken from private wells in San Roque and the Poblacion yielded water that exceed the permissible limits set by the National Standards for Drinking Water (NSDW).

Potable water supply thus comes mainly from the Manila Water and Sewerage System sources and distributed by Manila Water Company.

• Water Use and Regulation

The rivers of Pateros were once used as a transport channel and as a harbor for the Malay, Chinese, Swedish, and Indian vessels that periodically called to disembark merchandize and to engage in commerce in the Pateros, Pasig and neighboring areas. As previously mentioned, Pateros, which was then Aguho, has gained the monicker "embarcadero" meaning "small port".

The Pateros River accordingly was also used to support the duck raising and balut industry of the municipality. Because of pollution and residential encroachment and except for the annual fluvial parade along Pateros River, the rivers of Pateros are no longer used for transport nor for any economic activity. The ground waters of Pateros have also been assessed as unfit for human consumption.

Land Capability Classification

Land capability classification is attributed to physical characteristics (topography or slope, drainage, texture) and chemical characteristics (fertility, salinity). Studies show that the land capability of Pateros for cultivation is "very good" for more than half of the land area and "good" for the rest of the area. Likewise, the land capability for urban use is "very good" for more than half of the area and "moderate" for the remaining area. As such, while the town is considered as already urbanized, a small portion of the town is still being used for agricultural purposes.

ENVIRONMENTAL SITUATION

Water Pollution

• Surface Waters

The surface waters of Pateros are polluted and silted with almost the whole length of the Sta. Ana and Sto. Rosario rivers encroached by residential structures. The Pateros River, being part of the Pasig River Rehabilitation Project, is already being cleared of illegal settlers.

Pollution is mainly caused by wastewater and solid wastes while siltation is caused by solid wastes and solid particles that flow with stormwater run-off as well as soil erosion from river banks. Wastewater refers to both domestic and industrial sewage and other wastewater. There are four (4) industries located in Pateros that are potential sources of industrial sewage. All located along M. Flores Street in Barangay Sto. Rosario-Silangan, these industries are -

Nutri-licious Food Corporation - fruit juice, processed fruit, and purified water manufacturer;
Reed and Decker Industries, Inc. - paint manufacturing;
Ballet Plastic Packaging - plastic bottles manufacturing; and
Lavandero Industrial, Inc. - laundry services.

The effluent outfall of these industries is the Pateros River that eventually flows to Napindan River. Records from the Laguna Lake Development Authority (LLDA) showed that these companies do not dispose sewage effluent beyond set standards. This indicates that the major contributors to the pollution of the rivers are the households. This includes the significant number of households that used to throw their night soil into the river but are being reduced because of communal toilets and all the households whose other wastewater eventually end up in the rivers.

• Groundwater

The groundwater, as tested through samples from wells within the municipality, is not fit for human consumption. Although there were no available biological test results, a 1975 chemical analysis of water from public wells and selected private wells within the Laguna Lake Basin revealed that 2 of 3 samples from selected sites in Pateros exceed permissible limits set in the National Standards for Drinking Water. The pollution of the groundwater with e-coli can be traced to wastewater and sewage disposal. The open pit privy and the design of septic tanks allow the seepage of liquid sewage through the ground to the water table and contaminating it.

Environmental Sanitation

Pateros does not have a municipal sewerage. The most accepted method of managing sanitary sewage is the use of sanitary or water-sealed toilets that lead to a septic tank for digestion and leaching. In 1998, more than 700 households or 7% of the total households do not use any toilet facility. These households are those in the blighted areas of the municipality where the dwelling units are very crowded and where water supply is very limited. The usual practice was disposal of night soil into the river. With the communal toilet facilities constructed by the municipality, the households without toilet facilities significantly decreased in 1999 to less a hundred households that represent less than 1% of the total households.

The use of the communal toilets, however, raised issues on cleanliness and maintenance. These tasks are the responsibilities of household beneficiaries but some do not cooperate. Thus, they are locked and are available only for the use of households that maintain them.

Solid Waste Management

Pateros has an effective solid waste management system as proven by its awards in relation to this area. It won 1st runner up in the Cleanest and Greenest Municipality for 1997 as awarded by the National Capital Region (NCR) Search Committee for the Presidential award for the Cleanest and Greenest LGUs and the Cleanest Inland Bodies of Water. It again won 2nd runner-up for the same award in 1998.

• Generation

A 1997 Japan International Cooperation Agency (JICA) Study on Solid Waste Management for Metro Manila reveals that Pateros generates about 29 tons of solid wastes a day, the least among all the municipalities and cities of Metropolitan Manila (Table 3-4). This can be attributed to its population that is lowest in the region and its per capita solid waste generation that is second lowest at 0.52 kg/day.

The Waste Amount and Composition Survey (WACS) of the same study revealed that in Metro Manila, the highest generators are commercial establishments, restaurants in particular. Households are the second lowest generators with institutions producing the least quantity of solid wastes. Other types of generators classified in the Study are markets, streets, rivers (cleansing), and other commercial establishments. The WACS result has not been broken down per LGU but it can be inferred that this trend applies also in Pateros.

Per type of waste, the highest quantity generated is kitchen wastes, consistent with the highest solid waste generator, that is restaurants. The other types of wastes generated are paper, plastic, metals, grass and wood, leather and rubber, ceramic and stones, among others.

• Collection

The local government unit (LGU) conducts the collection of solid wastes in Pateros through its Environmental Sanitation Center (ESC) with assistance from the Metropolitan Manila Development Authority (MMDA) and a hired contractor. Pateros is the only LGU in Metro Manila that is still being assisted by MMDA in terms of rubbish collection through the detailing of collection trucks and staff.

The municipality owns one 12-m3 collection truck. Assigned from MMDA are one 12-m3 collection truck and one 6- m3 compactor. In addition to these, MMDA provides supplemental trucks (about two 6- m3 compactor) daily upon request and Pateros hires a contractor to ensure that all solid wastes are collected.

To facilitate collection, the town is divided into three (3) districts, consisting of District 1 - Barangays Sta. Ana, San Roque, Martirez, and Aguho; District 2 - Barangays Sto. Rosario-Silangan, Sto. Rosario-Kanluran, Magtanggol, Tabacalera, and San Pedro; and Barangay Poblacion as a lone barangay. The collection schedule is as follows:
District 1 - MWF
District 2 - TThS
Poblacion - Daily
Collection Efficiency

The 1997 JICA Study showed that only 48% of the solid wastes generated in Pateros are collected. This, however, is not accurate considering that the efficiency was determined by the quantity of wastes collected vis-à-vis the estimated generation. This did not consider resource recovery, such as segregation of recyclables and compostibles, which may have been conducted at source prior to collection.

The average volume collected per trip or per truck is 11.45 m3 which indicates that the collection vehicles are full during collection. The 1999 data will be used in the subsequent estimation of collection efficiency. The collection efficiency of Pateros is at 79% (without considering resource recovery at source) determined as follows:

Assumptions:

- waste volume collected in 1999 is the same as that of Year 2000
- average per capita generation is 0.50 kg.
- 0.30 tons/m3

• Disposal

Just like the other LGUs in Metro Manila, Pateros disposes its solid wastes in the San Mateo landfill located in San Mateo, Rizal. This site is scheduled for closure at the end of the year 2000 due to protests from the residents in the area. The MMDA, through the Office of the President, are accepting proposals from private proponents for viable alternative landfill sites.

• ESC Personnel

Sixty-seven (67) MMDA-detailed staff and four (4) local personnel man the Environmental Sanitation Center (ESC) of Pateros. Consisting of garbage collectors, sweepers, office staff, drivers, and the ESC head. All the local personnel are drivers.

Air Pollution

Air pollution is a common problem in densely populated areas. Major sources of air pollution are vehicular traffic and industries. In the case of Pateros where there are only four (4) industries that do not have significant volume of air pollutants, vehicles are the main sources of air pollution.

Modeling for air pollutants cannot focus on small areas such as Pateros. The domain must be so large as to encompass all pollutant sources that contribute to ground level concentrations in the region. The whole of Metro Manila must be modeled so that any trans-boundary fluxes of pollutants are negligible.

A study conducted in Metro Manila in 1975 to 1978 (Isidro-Valeroso and Monteverde, 1992) on the diurnal variations of the concentrations of atmospheric pollutants showed two types of concentration variations exhibited by the pollutants depending whether these are photochemically reactive (NO2, S O2, HC, and Ox) or non-photochemically reactive (CO and particulate matter). Samples were taken in five (5) sites, namely Quiapo, Herran, Pasay, Cubao, and Bicutan. The variation corresponding to non-photochemically reactive pollutants show two maxima, one in the morning at 8:00 A.M. and a secondary in the evening from 8:00 - 9:00 P.M. The photochemically reactive pollutants exhibit only a single maximum at about noontime or early afternoon.

Another study on air pollution planning for Metro Manila (Manins, 1991) used a grid pattern in identifying sample sites. Sulfur dioxide (SO2) emissions from mobile sources or vehicles. The other LGUs have more than one sample since their areas are included in more than one grid. The quantity of SO2 emissions depends on the traffic volume apart from meteorological factors as wind direction.

KEY ENVIRONMENTAL ISSUES AND CONCERNS

Except for geological concerns, environmental issues in Pateros are linked to it's being part of Metro Manila.

Pateros is subject to natural hazards

• Flooding

Heavy rains accompanying typhoons or the southwest monsoon usually cause flooding. Flooding is a chronic problem afflicting large areas of Pateros, specifically the western portion of the municipality near the Pateros River and the low-lying areas adjacent to the Sta. Ana River such as Barangays Sta. Ana and San Roque. Because of the local climatic condition, Metro Manila is visited by an average of 18-20 flood events yearly, although only a few causes severe damage (Punongbayan, et.al., 1993). It is estimated that 47% of the average annual rainfall is due to typhoons. Floodwaters are usually due to excessive rainfall particular during the months of May-November when the southwest monsoon coincides with the typhoon season.

Flooding problems are aggravated by inadequate or non-existent drainage, improper waste disposal, low river capacity due to siltation and lack of maintenance, tidal transgressions. For Pateros, flooding is also affected by the behavior of Manila Bay and Laguna Bay that may result to backwash of the Pasig River and Pateros River during heavy rains and typhoons.

• Volcanic Hazard

There are two active volcanoes - Pinatubo and Taal - which are possible sources of volcanic hazard to Metro Manila. Due to its relative distance, however, light moderate ashfalls are the only volcanic hazard that may be expected to affect the metropolis. This adds to sediments in the water bodies. The June 15 1991 Pinatubo Volcano eruption showered Metro Manila and adjacent areas with a few millimeter thick ashfall. Some parts of the metropolis were also deposited with considerable amounts of ashfall during the past eruptions of Taal Volcano in 11754, 1922, 1965-1969.

• Earthquake

Pateros has experienced numerous earthquakes in the past. Statistically, Metro Manila is likely to be hit by a strong (Intensity 7) earthquake every 17 years. The return period of an Intensity 8 earthquake similar to the July 1990 earthquake is about 79 years.

Five seismic source zones have been identified as the loci of major earthquake that hit Metro Manila in the past. These are the MVFS, PFZ, Lubang Fault, Casiguran Fault, and Manila Trench. Pateros is traversed by the MVFS.

The chief seismic hazards to which Pateros is prone are ground shaking, liquefaction, and surface rupturing. Of the five seismic sources, the MVFS and the Philippine Fault Zone will most likely generate the strongest level of ground shaking in the metropolis (Punongbayan, et.al., 1993).

Aside from the earthquake magnitude and the distance from the earthquake source, ground shaking for a given site is determined to a large extent by the character of the underlying substrate. Pateros is underlain by two distinct lithologic units, the Guadalupe Formation and the Quaternary to Recent Alluvium (Marikina Series). These formations are cut by the MVFS. The areas underlain by soft and thick sequence of fine sediments will most likely experience average to above average levels of ground shaking depending on the thickness of these soft materials. Similarly, the eastern portion of Pateros falls under the above average severity while the western portion fall under the average severity.

Among the identified potential earthquake generators, the MVFS, particularly the West Marikina Valley Fault, could produce a surface rupture that could affect certain areas within the metropolis. In general, the stronger the earthquake, the longer the expected length of the surface rupture and consequently, the larger anticipated maximum displacements. At least 5 meters on either side of the mapped active fault traces is recommended as a buffer zone. Within this 10 meter wide zone, allowable land use should be limited to open space, parks, and similar low intensity land utilization activities.

An evaluation based on the depth of water table, thickness of saturated sand layers, and to a limited extent, grain size characteristics to determine potential for liquefaction shows that Pateros has high liquefaction potential. The identified liquefaction-prone areas have characteristically willow water table (3 meters or less) with thick (10 meters or more) piles of water-saturated fine sediments (sand to clayey sand).

Similarly, Saldivar-Sali classified Pateros as very high earthquake risk based on the types of soil or rock material, the depth of the adobe bedrock (or thickness of the soil) which in turn, controls resonance or swaying of a structure.

Lack of green/open spaces

Although the soil in Pateros is moderately found to be highly suitable for the growing of trees and agricultural crops, its dominantly urban landscape and limited land area constrain such activity. The town is thus, characterized by very limited green and open spaces. There is a need, therefore, to maximize the use of potential open spaces such as riverbanks and school grounds.

Alarming rate of urban environmental degradation

• Contaminated water resources

Both surface and ground waters are contaminated. All surface waters are polluted and silted. With the exception of Pateros River that still flows and has at least retained its width throughout its length, the other rivers in the municipality are reduced to small creeks and canals due to encroachment of residences, solid wastes on its banks, and growth of water hyacinth. This is a far cry from the clear waters of these rivers in the 1960s. Ground waters, meanwhile, are not fit for human consumption. This situation makes Pateros dependent on outside sources for its water needs.

• Absence of a municipal sewerage and lack of sanitation facilities

Despite the provision of communal toilets for households in several congested residences, there are still a number of families that do not have any toilet facilities. Also, some household beneficiaries of communal toilets do not cooperate in the cleaning and maintenance of said facilities thus some of these toilets are locked for use only of the families who help in the cleaning. This indicates that there are still households who dispose their night soil in the rivers and creeks.

Further, although more than 90% of households use sanitary facilities with corresponding septic tanks, this does not warrant an acceptable effluent disposed onto the waterways. Septic tanks with their digestive and leaching chambers reduce the biochemical oxygen demand (BOD) of the sewage by only 40% which results to an effluent that is not within set standards. Attainment of acceptable effluent quality requires the installation of municipal wastewater treatment facilities with the required network of sewers to collect the wastewater for treatment.

• Noise pollution and air pollution due to traffic

Since Pateros is situated adjacent to Pasig City, Makati City, and Taguig, traffic to and from these areas will enter or pass through Pateros. The expected high volume of vehicles is factors that affect noise and air pollution in the municipality's main thoroughfares.

• Increasing generation of solid wastes

As population grows, it is expected that the production of solid wastes will also correspondingly increase, that is, if measures are not done to minimize waste generation. An increase in generated solid wastes will have a consequent effect on the collection and disposal capacity as well as the administrative capability to manage these activities. At present, Pateros is not capable to collect the generated solid wastes in the municipality with its own resources, thus the assistance from MMDA. An increase in the quantity of solid wastes generated by the people may require additional collection vehicles and personnel. The closure of the Sto. Mateo Landfill by the end of the year 2000 poses a bigger problem, in terms of solid waste disposal.

DEVELOPMENT CONSTRAINTS AND OPPORTUNITIES

Constraints

• Geological Characteristics

Pateros has a slope of up to 2.5% only. This affects the natural flow of storm run-off and would require appropriate engineering intervention to ensure that the needed slope for drainage is met and to avoid pond formation and floods in certain areas. This situation is alleviated by the municipality's elevation, that is, between 2.0 m. to 4.0 m. which is almost at sea level. High tide in Manila Bay causes backflow of the Pasig River and its tributaries including Pateros River. Such situation, coupled with heavy rains and a very low natural slope for drainage, Pateros gets locked in floodwaters rising until waist-high on many occasions. This requires strategies to prevent the overflow of waterways while at the same time being able to remove storm water run-off collected within the area.

Moreover, Pateros is within the West MVFS making it vulnerable to ground shaking, liquefaction, and surface rupturing. It is classified as very high earthquake risk based on a foundation engineering perspective. Such situation limits the development of man-made structures or requires specialized attention to the structural integrity of large infrastructure developments.

• Geographical Location

Pateros, with its small land area, is surrounded by three (3) urban local government units, Makati City and Pasig City, that are highly urbanized with their consequent urban environmental problems. Taguig, being part of Metropolitan Manila, is also moving towards that level of urbanization.

Pollution cuts through geographical boundaries. Air pollution depends upon wind and other climatic factors. The absence of air polluting industries does not guarantee a cleaner air in the municipality or does it limit air pollution sources to vehicle emissions. The area and its neighbors are roofed by an airshed where air movement is governed by various meteorological factors. The same is true with water pollution. Even if the rivers and creeks of Pateros will be dredged and improved, pollution from the Pasig River will eventually creep in because of water backflow during high tide. Rivers and creeks form a network that affects every branch.

Since pollution cuts across boundaries, it requires an integrated approach in river rehabilitation and in abating air pollution. Such situation is an advantage for Pateros with its limited resources. Pollution management programs are conducted metropolitan-wide. The municipal government has to make sure that it becomes part of such undertakings and that it is given adequate assistance.

• Existence of Blighted Areas

Blight areas in Pateros do not always mean squatters or illegal settlers. There are areas in the town that are so congested and do not have the needed infrastructure facilities such as drainage and sanitary facilities that they become unsanitary and become sources of environmental problems. The congested population generates so much solid wastes in a relatively small land area that its management, specifically storage for collection, becomes difficult. Some wastes are thrown onto nearby rivers or creek. The lack of sanitation facilities results to disposal of night soil also onto the river. Further, most of these blight areas are in flood-prone locations increasing environmental problems during floods with wastes floating with the water and accelerating occurrence of water-borne diseases.

Development Opportunities

• Manageability of the Area

The limited land area of Pateros can be considered a distinct advantage and an opportunity to undertake realizable environmental programs and projects. With a responsive planning and budgeting process, priority programs to address the environmental concerns can be easily undertaken and adequately managed.

• Metro-wide Urban Management

The environmental issues concerning Pateros extends beyond its municipal boundaries. This would require the cooperation of adjoining cities and municipalities in Metro Manila. Pateros is part of the MMDA and this could serve as a venue to promote concerted action to address the environmental problems in Pateros and nearby localities.