Environmental Risk Assessment

ENVIRONMENTAL RISK ASSESSMENT

PRO-POOR ECO-SETTLEMENT PROJECT

PAYATAS SCAVENGERS HOMEOWNERS ASSOCIATION, INC (PSHAI) Miraculous Subdivision, Barangay San Isidro Municipality of Rodriguez (Montalban), Rizal Province Philippines

Prepared by

Ms. Iris Legal Ms. Dallay Annawi Dr. Peter Walpole

TABLE OF CONTENT

1. INTRODUCTION...... 4 2. MIRACULOUS HILLS SUBDIVISION, BARANGAY SAN ISIDRO, RODRIGUEZ.....5 2.A. PHYSICAL...... 5 2.B. SURFACE DRAINAGE PATTERN...... 5 2.C. VEGETATION ...... 7 2.D. ECONOMIC AND LIVELIHOOD ...... 7 2.E. ORGANIZATION AND INSTITUTIONAL ...... 7 3. MUNICIPALITY OF RODRIGUEZ, PROVINCE OF RIZAL ...... 8 3.A. LAND USE PATTERN ...... 8 3.B. TOPOGRAPHY ...... 10 2.C. GEOLOGY ...... 11 3.D. NEARBY SETTLEMENTS, INSTITUTION, POPULATION...... 11 3.E. LOCAL ECONOMIC DEVELOPMENT AND ROLE OF LGU...... 15 4. ENVIRONMENTAL RISK ASSESSMENT ...... 17 4.A. READING AND RESPONDING TO SIGNS OF SLOPE PROBLEMS, BLOCKS 1 TO 10: MAP 3 19 4.B. READING AND RESPONDING TO SIGNS OF SLOPE PROBLEMS, BLOCKS 11 TO 15: MAP 4 ...... 19 4.C. READING AND RESPONDING TO SIGNS OF SLOPE PROBLEMS, BLOCKS 16 TO 20: MAP 5 ...... 19 4.D. CHERRY HILLS SUBDIVISION (ANTIPOLO, RIZAL): REVISITED AFTER A DECADE...... 24 5. STRATEGY AND COMMUNITY ACTION PLAN ...... 29 5.A. RECOMMENDATIONS...... 32 6. GOOD PRACTICES: SOIL EROSION MANAGEMENT ...... 34 7. POINTS TO CONSIDER IN BUILDING ECO-SETTLEMENT SITE...... 37 REFERENCES...... 38

2 List of Annex

ANNEX 1: GENERAL ZONING MAP, MUNICIPALITY OF RODRIGUEZ, RIZAL ...... 39 ANNEX 2: URBAN ZONING MAP, MUNICIPALITY OF RODRIGUEZ, RIZAL ...... 40 ANNEX 3: HOUSEHOLDS BY TYPE OF BUILDING, KIND OF TOILET FACILITY USED, MUNICIPALITY OF RODRIGUEZ (1990)...... 41 ANNEX 4: HOUSEHOLDS BY TYPE OF BUILDING, MAIN SOURCE OF DRINKING WATER, MUNICIPALITY OF RODRIGUEZ (1990)...... 42 ANNEX 5: HOUSEHOLDS BY TYPE OF BUILDING, FUEL USED FOR LIGHTING, MUNICIPALITY OF RODRIGUEZ (1990)...... 42

List of Map

MAP 1: PAYATAS SCAVENGERS HOMEOWNERS ASSOCIATION, INC. (PSHAI) TOPOGRAPHIC PLAN...... 6 MAP 2: TOPOGRAPHY AND WATERSHED OF PURAY RIVER AND COGEO RIVER, RIZAL PROVINCE ...... 12 MAP 3: READING AND RESPONDING TO SIGNS OF SLOPE PROBLEMS, BLOCKS 1 TO 10...... 21 MAP 4: READING AND RESPONDING TO SIGNS OF SLOPE PROBLEMS, BLOCKS 11 TO 15...... 22 MAP 5: READING AND RESPONDING TO SIGNS OF SLOPE PROBLEMS, BLOCKS 16 - OCK23 MAP 6: PAYATAS SCAVENGERS HOMEOWNERS ASSOCIATION, INC. (PSHAI) SITE PLAN ...... 31

List of Table

TABLE 1: COMPARATIVE LAND USE IN RODRIGUEZ, 1980 AND 1995...... 8 TABLE 2: REGIONAL GEOLOGIC SETTING ...... 13 TABLE 3: GEOHAZARD IDENTIFICATION SURVEY AND GEOHAZARD ASSESSMENT FINDINGS....18 TABLE 4: CHERRY HILLS REVISITED, JULY 2010 (CF PHOTO 1)...... 25 TABLE 5: CHERRY HILLS AND MIRACULOUS HILLS SUBDIVISIONS CHARACTERISATION...... 26

3 1. Introduction The Payatas Scavengers Homeowner!s Association (PSHAI)1 started as one of the savings groups in Payatas in the early 1990s organized by the Vincentian Missionaries Social Development Foundation (VMSDF). At first, they saved for their social and economic needs, start-up capital for livelihood projects, hospitalization bills, education needs of their children, etc. In 1995, they began to save for land and housing with the goal of buying a titled property where they could build their houses in the future and live without the fear of being evicted.

PSHAI was formally organised in 1998, composed of members of the savings groups who committed to contribute their individual savings and to pay monthly amortization to purchase a titled lot in San Isidro, Rodriguez where they would build their houses. PSHAI named their housing project site as “Miraculous Hills Subdivision”.

PSHAI bought a 30,000-square meter lot in San Isidro, Rodriguez in December 1998. This was two years before the dump-slide disaster in Payatas in July 2000. It was the first community-led land acquisition effort through the Homeless Peoples! Federation of the Philippines (HPFPI) savings scheme. The members used their three-year savings as down payment for the lot and accessed a low-interest loan from the Domus-Mariae Foundation2 for the full payment. They are still repaying the loan in monthly amortization of PhP 540 per member.3 Although the development of the site was to be self-financed mainly by the members, the construction of two row houses, the opening and concreting of the road and the construction of an activity center were fast-tracked in 2001 through the VMSDF and HPFPI to provide decent shelter for some families displaced during the Payatas dump-slide disaster.4

PSHAI, with HPFPI assistance, is the developer of their housing project. Without prior experience or knowledge on land acquisition or housing-related government processes, PSHAI learned their way as they navigated levels of bureaucratic requirements and procedures. Because of this participatory and community-led approach of PSHAI, the association is identified as one of the sites (in the Philippines) for the Pro-Poor Eco- Settlement Demonstration Project of the UN-ESCAP.

The Demonstration Project of the UN-ESCAP called, “Eco-Efficient and Sustainable Urban Infrastructure in Asia and Latin America” seeks to develop a set of principles, guidelines, and strategies for policy-makers and planners to develop eco-efficient and sustainable urban infrastructure. It also aims to merge eco-friendly options for housing, infrastructure, services, and livelihood provision that are affordable to the poor (and therefore replicable) with participatory and community-led management.

Parallel to the UN-ESCAP research work is the implementation of the Community-led Infrastructure Facility Financing (CLIFF) housing project. Initially, 70 families are targeted each year to benefit this project. The project would run for five years and is expected to have served most of PSHAI members.

1 PSHAI now has 264 members. In 2006, PSHAI opened the membership in the housing association to urban poor families that are interested in saving for a lot even if they are not original members of their savings program. 2 Domus-Mariae Foundation is a non-profit organization assisting the urban poor to acquire low-cost housing. 3 The monthly amortization also covers miscellaneous expenses that are incurred in the processing of bureaucratic requirements. Aside from this, the members also contribute PhP 50 a year for their annual property tax. 4 The costs of these infrastructures are to be repaid by the PSHAI members in the future.

4 2. Miraculous Hills Subdivision, Barangay San Isidro, Rodriguez

2.a. Physical The Miraculous Hills Subdivision is located at Barangay San Isidro, Rodriguez, Rizal, which approximately lies at 140 45! 35” N and 1210 09! 40” E. The site forms part of the lowland section of the Puray Watershed that originates from the southwestern mountains of Sierra Madre. Puray River then joins the Tanog River and the single channel flows to the Wawa River that drains into the Marikina River then discharges to Laguna de Bay.

The subdivision has total area of about 30,000 square meters and is approximately three kilometers away from the town proper of Rodriguez. The major roads are well paved and fairly maintained while minor roads are combination of compacted earth- soils and stones.

Generally, the topography (Map 1) of the Miraculous Hills Subdivision is gently rolling to undulating slope, which range from 10 to almost 60 degrees while elevation range from 45 to 95 meters above sea level (masl).

The site falls within the Type 1 Climate characterized by two pronounced seasons: dry season from December to April and wet season from May to November. Based on the monthly rainfall averages taken at the nearest rain gauge located in the PAGASA national office in Science Garden, Quezon City, rainfall peaks in the months of July to September (highest in August). Being closer to the mountains, it may be expected to receive some further rain. Further, based on PAGASA!s typhoon frequency classification, the subdivision lies within a zone that directly experiences typhoons at a rate of five times in three years generally originating in the Pacific Ocean. They occur within the wet season particularly in the months of July and August.

2.b. Surface drainage pattern The creeks in the site are ephemeral. A gully on the northern border section (Map 1, Block 10) of the lot serves as the natural drainage channel of the northern half of the lot. Sediment deposit is building up on the low, flat area of the gully. Drainage within the middle section (Map 1, Block 14) is through a creek that originates from a concave slope outside of the lot boundary. Along the channel in the southern area (Map 1, Block 18), a short-term pool and a spring and seepage emerge after extended and intense rains. Evidence of shallow water table in the site includes ponding, springs, seepage, and short-term pool, which is evident only during the rainy season.

5 2.c. Vegetation Cassava (Manihot esculenta), taro (family: Araceae), corn (maize), pineapple (Ananas comosus) and some other vegetables are grown in a number of lots that are not yet built on. There are also some fruit trees like mango (Magnifer indica) and sampaloc (Tamarindus indica) as well as bamboo (family: Poaceae) and banana (genus: Musa). Grass is the dominant vegetation in the adjoining undeveloped private lots in some cultivated individual lots within the housing site.

2.d. Economic and livelihood Majority of the community members are still living outside Miraculous Hills Subdivision, earning their livelihood mainly from the Payatas Dumpsite, vending, and casual or manual workers. On the other hand, the members living onsite are engaged in hog raising, plastic collection, vending, construction work, driving, and others. Some are engaged in vegetable (and some fruits) gardening.

2.e. Organization and institutional PSHAI is a member of the Homeless Peoples Federation in the Philippines, Inc. (HPFPI). As a member, PSHAI members are encouraged to engaged on family- savings for housing and development. The membership of HPFPI is spread throughout the Philippines among urban poor associations, homeowners, and area centres.

The Philippine Action for Community-Led Shelter Initiatives, Inc. (PACSII), on the other hand is an NGO that provides technical support to the HPFPI in terms of linkages, resource mobilization, direction setting, research, and training.

Recently, PSHAI had an election for new sets of officers and board members. There is also an existing youth organisation that supports the activities of PSHAI.

7 3. Municipality of Rodriguez, Province of Rizal

3.a. Land use pattern Rodriguez (formerly known as Montalban) is the largest town in the province of Rizal, with an estimated area of 313 square kilometers. It is considered a first class municipality in the province. Located at the slopes of the Sierra Madre, Rodriguez lies south of Bulacan, east of Metro Manila, and north of San Mateo and Antipolo. The municipality is accessible from Quezon City through a road connecting Barangay Payatas (Quezon City) and Barangay San Jose (Rodriguez) and from Marikina City through the Marikina-San Mateo Road. Rodriguez!s accessibility and proximity to the metropolis and highly urbanized towns have been affecting its land use and growth pattern through the years. Development in the area has been rapid brought by its varied resources.

Between 1980 and 1995, there have been major changes in the landuse in the municipality, Table 1. In 1995, forest remained the dominant landuse of the municipality, covering almost one half (50.4 percent) of its total land area. However, about 40 percent of the forest was lost since 1980, when forests covered almost the entire town (91.3 percent). It is perceived that most of this is not original forest cover but in the past was heavily logged over with some reforestation schemes and orchids resulting in a one canopy cover still subject to erosion.

The total land area (Table 1) varies and do not match with the municipal technical description i.e. 31, 300 hectare, which may be due to conflicting data sets and consideration of increased area due to slope inclusion.

The remaining forested area lies in the east within the Marikina Watershed Reservation, which has been declared under Executive Order (EO) No. 33 and Presidential Proclamation No. 1637 as a critical watershed that cannot be subjected to commercial logging and other destructive activities.

Table 1: Comparative Land Use in Rodriguez, 1980 and 19955

Percent Land Use 1980 1995 Change Area (ha) % to Total Area (ha) % to Total 1980-1995

Forest (Mixed) 31,575.3 91.3 18,887 50.4 40.2(-)

Open Grassland 1,745.5 5.0 16,218 43.3 829.1(+)

Agriculture 756.4 2.2 1,148 3.1 51.8(+)

Orchard 372 0.9

Built-up Area 505.8 1.5 791 2.1 56.4(+)

Quarry 72 0.2

Total 34,583.0 100.0 37,488 100.1 " Source: 1998 Comprehensive Development Plan of Rodriguez.

5 The latest landuse data obtained from the Municipal Planning and Development Office (MPDO) is 1995 data, which is incorporated in their Comprehensive Development Plan (1998). Currently, the MPDO is planning to update their Comprehensive Land Use Plan (CLUP).

8 With the decline of forest areas, open grasslands or underutilized lands significantly increased from only 5.0 percent of the land area in 1980 to 43.3 percent in 1995. Agricultural lands also increased from 2.2 to 3.1 percent of the total land area but may probably have larger area as it is not continuously or intensely used. Additional landuse included in the 1995 classification are orchards (about one percent of the land area) and quarry (0.02 percent).

In the span of 15 years (1980 – 1995), settlements (or built up areas) have increased by about 56.4 percent. As of 1995, the built-up land comprised 2.1 percent of the town. The built up area is expected to have increase considering the numerous housing and relocation projects that were constructed in the municipality in recent years.

The relatively small urban area is located mainly in Barangays Burgos, San Rafael, Manggahan, Rosario, Balite, Geronimo, and San Jose, with a small portion in the southern part of Barangay San Isidro. The most extensive urban land use is the residential lots alongside Rodriguez Highway, main streets of Rizal Avenue, M.H. del Pilar, A. Bonifacio, and Daan Bakal, and the north-south stretch and west of San Mateo River. The temporary housing areas (informal settlers) are found mostly along the Montalban River in the west and north of the whole built-up area. These are located in Barangays San Jose, Balite, Rosario, Geronimo, and San Rafael. (cf Annex 1 and 2).

According to the Municipal Urban Zoning Plan, San Isidro is classified as the area for socialized residential zone with medium-size density (R2). An R-2 district is a medium-density residential zone characterized mainly by 21 to 65 dwelling units per hectare or medium-density housing like two-family dwellings, townhouses, accessories or row houses, and other low-area, medium-rise, multi-family dwellings on a limited scale with usual community ancillary uses and support facilities designed for the needs of barangay scale.

Based on the Municipal Ordinance, Article VI, Section 3, an R-2 district is a medium-density residential zone characterized mainly by 21 to 65 dwelling units per hectare or medium-density housing like two-family dwellings, townhouses, accessories or row houses, and other low-area, medium-rise, multi-family dwellings on a limited scale with usual community ancillary uses and support facilities designed for the needs of a barangay scale. The following are allowed within this category:

a. All uses allowed in R-1 zone (R-1 characterised by single-family, single-detached dwellings. It shall be used primarily for residential purposes so as to maintain the peace and quiet of the area within the zone with a density of twenty dwelling units per hectare); b. Two-family dwellings; c. Residential condominiums of medium-rise type; d. Apartment houses, apartment hotels and hometels; e. Multi-family dwellings; f. Boarding houses;

9 g. Nursery, kindergarten, and elementary schools provided this will not exceed 12 classrooms; h. Clinics, family planning clinics, and industrial clinics; i. Local civic centres, local auditoriums, halls, and exhibition areas;

j. Home occupations as provided in R-1 zone including customarily incidental occupations such as: barber and beauty shops, tailoring and dress shops, neighbourhood convenience stores, and retail drugstores; and k. Parks and playgrounds.

The municipal government of Rodriguez acknowledges the need for more frequent planning considering the fast pace of development in its town, which is adjacent to dynamic Metro Manila. The revision of the plan is needed based on the following considerations:

a. Population increase due to migration;

b. Emergence of new laws, policies, and concepts related to planning towards industrialisation;

c. Physical constraints affecting development such as flooding of lowland areas (Barangays Rosario and San Jose) during monsoonal and typhoon rains, the west and east Marikina fault lines, which traverse both sides of Rodriguez from north and south, and the diminishing groundwater supply;

d. Inclusion to CALABARZON (Cavite, Laguna, Batangas, Rizal, and Quezon) development plan. These provinces are expected to evolve into an industrial area and act as catalyst for development in Region IV and driving force for the industrialisation of the country; and

e. MARILAQUE (Manila, Rizal, Laguna, and Quezon) growth area plan. Based on Executive Order No. 197, which tasked and vested the Presidential Commission of MARILAQUE to plan and develop growth area that will transform these areas into an economically progressive area hence improve quality of life of the residents.

Generally, the municipality need to also consider its absorptive capacity i.e. capability of the area to absorb the projected urban needs of the town in terms of space. The suitability for urban expansion needs to examine in particular the factors of slope, soil, elevation, and geology. Based on the general land use plan (cf Annex 1) about eight square kilometers (791 hectares) (Table 1) are already under urban uses however, considering the urbanizable areas based on land capability, a total of 50 square kilometers is suggested for urban especially the agricultural lands that are very close to existing built-up areas.

3.b. Topography The topography of Rodriguez is generally very rough with 83 percent of its total land area composed of upland areas, hills and mountain ranges. The low-lying terrain and rolling lands are found at the southwestern portion of the municipality along with the northern portion of the Municipality of San Mateo. Several major rivers drain the

10 high elevation areas, namely: Tanay River, Puray River, and Montalban River. (Map 2).

2.c. Geology According to the Mines Geosciences Bureau (MGB), at least six major geologic formations are found in the area, Table 2. From young to old, these are: Quaternary Alluvium (QAI), Guadalupe Formation (GF), Madlum Formation (MF), Angat Formation (AF), Gabbro (G), and Kinabuan Formation (KF).

3.d. Nearby settlements, institution, population As of 2007, the Municipality has a population of around 223,594 with a population density of 714 per square kilometer. Almost 80 percent of the households are made up of single houses. Institutional and commercial buildings are less than one percent, which indicates that the town is largely residential in nature as it serves as a catchment area for the overspill of developments in the National Capital Region (NCR).

Most households rely on community water system (44 percent) and deep wells (40 percent) for their drinking water. However, there are about 10 percent who rely on springs, lakes, rivers, and rains for their drinking water.

According to 1998 data, about 70 percent of the population used electricity for lighting, which means the town is still not fully electrified.

The common type of fuel used for cooking by households is LPG (liquefied petroleum gas). As the local government would define it, it is the most convenient and the most cost-effective mode of cooking. Other major fuels used are wood, charcoal and kerosene. cf Annex 3, 4, and 5 for summary tables.

11 Table 2: Regional geologic setting

GEOLOGIC TIME: STRATIGRAPHY HYDROGEOLOGICAL RELATIVE HYDRAULIC LITHOLOGY DESCRIPTION CHARACTERISTICS6 CONDUCTIVITY7 Era Period Epoch Age Alluvium Composed of detrital deposits formed on valleys by Holocene Marikina graben (Marikina stream action and essentially made up of silt, sand, and Productive aquifer Very good River) gravel.

Consists of two members: the upper Diliman Tuff and Guadalupe Formation8 the underlying Alat Conglomerate. The upper member Guadalupe, Makati City composed of thin to medium beds of fine-grained vitric Low to moderate

Quaternary Pleistocene Laguna de Bay and extends tuffs. Volcanic breccias are sparingly intercalated with aquifer with level of Poor to good

as far as Nueva Ecija in the some lamellae of fine- to medium-grained sand stones. unproductive aquifer north Alat Conglomerate is a massive conglomerate, deeply weathered silty mudstone, and tuffaceous sandstone. Cenozoic Composed of three members: lower Madlum Clastics, middle Alagao Volcanics, and the upper Buenacop

Limestone. Madlum Clastics is a thick sequence of thin- to thick-bedded sandstone and silty shale. Alagao Moderate to productive Fair to good with very Middle Madlum Formation Volcanics is composed of agglomerates, tuffs, argillites, with level of poor conductivity for the Miocene indurated graywackers, and andesite flows. The unproductive aquifer clay level Neogene Buenacop Limestone is composed of cream to buff fossiliferous, massive or obscurely bedded upper part and thin to medium bedded lower part.

6 Describes the type of aquifer. Aquifer is defined as underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, silt, or clay) from which groundwater can be usefully extracted using water well (Ang AQUIFER ay ang ilalim na bahagi ng lupa kung saan natatagusan ito ng tubig at mga graba, buhangin, banlik, o luwad at maaaring pagmulan ng tubig-bukal).

7 It is a property of vascular plants, soil or rock that describes the ease with which water can move through pore spaces or fractures. It depends on the intrinsic permeability of the material and on the degree of saturation (Ito ang kakayahan ng halaman, lupa, o bato na pabilisin or pabagalin ang daloy ng tubig sa mga butas o puwang nito. Ang kakayahan na ito ay depende sa antas ng daluyan ng tubig at lunod nito).

8 Miraculous Hills Subdivision is located in this type of unit specifically the Alat Conglomerate. Although this is the general description used by the Mines and Geosciences Bureau (MGB), the PSHAI Geohazard Assessment Report (2004) had some questions thus needs further study.

13 GEOLOGIC TIME: STRATIGRAPHY HYDROGEOLOGICAL RELATIVE HYDRAULIC LITHOLOGY DESCRIPTION CHARACTERISTICS6 CONDUCTIVITY7 Era Period Epoch Age

Composed of upper and lower facies. The upper is a limestone facies while the body is well embedded to

massive and laminated with siliceous materials and Early Angat Formation limy sandstone. Constituting the lower facies isa bedded sequence of calcareous shale, clayey sandstone, sandy limestone, and conglomerate.

Massive layered norite partly normal gabbro and Gabbro pegmatitic anorthosite.

Kinabuan Formation Composed mainly of spilitic basalts and minor Local low aquifer with Cretaceous Late Santa Ines, Antipolo City intercalations of highly indurated sandstone, shale, superficial moderate Poor to fair and Kinabuan Creek limestone, and chert beds. aquifer Mesozoic

14 3.e. Local economic development and role of LGU The Provincial Government of Rizal recognises that the there is a need to improve its land transportation infrastructure, including power, water, and communication utilities and hazard-mitigating facilities to meet the fast-growing activities in the province. These proposals are included in the final Provincial Physical Framework Plan or the Comprehensive Provincial Land Use Plan for the Province 1993 to 2002.

It is expected that residents in Rodriguez shall increase in numbers in the succeeding years due to the following “push-pull” factors:

• Strong economic activity, not only in the town proper but also in other barangays of Rizal;

• Identified as relocation sites of most informal settlers from Metro Manila i.e. location of Erap City, Pamayanan ng Tagumpay (Iglesia ni Cristo!s housing for its members);

• Conversion of Rizal State College into a university status; and

• Aside from government housing projects, there are also subdivisions owned by private corporations and individuals are found in the municipality.

The towns of Rizal adjoining Metro Manila are envisioned as the province!s future suburban industrial area. The role of Rodriguez and other towns will be changed from that of “bedroom communities” to absorber of industrial overspill.

The northwest of the poblacion of Barangay San Isidro (cf Annex 1 and 2), close to the boundary of Barangay Macabud, is identified as the agri-industrial zone (AIZ). This zone is devoted to industries, which are agriculturally derived. Among the industries are poultry and piggery establishments. At present, the agro- industrial activities are rather scattered over the built-up area, which sometimes resulted to nuisance to residents due to its foul odor and waste effluents.

The hilly portions of the town of Barangays San Isidro, San Rafael, Mascap, and Puray are designated for vegetable growing to become vegetable “basket” for nearby Metro Manila. Further, the production forest (PdFZ) in Barangays San Isidro and Mascap are identified as expansion area for orchard/ production forest.

The municipal government of Rodriguez agreed to accommodate the garbage of Metro Manila through an engineered landfill located in Lukutang Munti, Barangay San Isidro. This agreement is signed on the basis that: 1) the Payatas Dumpsite be totally closed; 2) the roads leading to the engineered dumpsite be properly paved and reinforced before the start of dumping in Rodriguez; and 3) residents of Rodriguez be given priority in the salvaging of garbage and that the garbage trucks have no stop-overs in Payatas.

Initially, the landfill at Lukutang Munti has an estimated area of 50,000 square meters. This would eventually be developed into a permanent landfill with a total land area of 1,000,000 square meters. In December 2001, former President Gloria Arroyo earmarked PhP 40 million for the operation of the landfill and other related support facilities like widening and patching of roads going to the garbage site.

15 As stated in the plan, a waste segregation and recycling program will be implemented aside from the regular collection of wastes. Moreover, the dumping of garbage in the town!s rivers is highly prohibited.

16 4. Environmental Risk Assessment In 2004, PSHAI complied with the geohazard identification survey and geohazard assessment (GIS-GAR) system, which is a requirement for housing development projects, under the Mines and Geosciences Bureau (DENR). The GAR found out that, in general, the site is suitable for housing development. But while it is not critical for residential use, some geohazards are present in certain areas. The GAR findings and recommendations are summarised in Table 3. These findings, however, were not taken into consideration in the site planning and processing of the development permit from the Rodriguez municipal government for the housing project.

Conducted independently of the GAR, the assessment done by the Environmental Science for Social Change (ESSC) coincided and added to the GAR findings. Aside from the sloping condition, the ESSC assessment took into consideration the likelihood of landslides with “buriable” conditions – where there is a potential that people or houses may be buried under mud or be carried away by mass movement downhill as is common in channel or stream areas during prolonged rains. Under these conditions, building houses in the following areas must be avoided: a) corner lots of Block 14; b) steep lots on Block 15; and c) lower lots of Block 18. In relation to this, it must be stressed that PSHAI should adhere to the GAR recommendations of avoiding moderate to steep slopes in the site.

Avoiding building on problematic slopes will save the concerned members from future complications and problems associated with slope cutting. Cutting into the hillslope along the boundary line would create a steep side that can be a threat to the houses. It would not allow enough space for slope grading to stabilise the steep side and may require long-term stabilisation and maintenance. Another consideration is !surface dynamics," where surface runoff resulting in heavy erosion leads to slow but cumulative deterioration of ground conditions in the site and to sedimentation of lower areas.

Nevertheless, the reported plan about the development of the adjoining lot for the relocation of some informal settlers from Payatas or other parts of Metro Manila, in which the concave slope and the remaining hillsides along Blocks 10 and Upper Block 18 are to be removed, will significantly reduce the risks to the corner lots in Block 14, Block 10, and Upper Block 18.

Heavy erosion and sedimentation are taking place in several areas in the site. A common evidence of intense erosion is the exposure of small stones on the soil surface after the soil is carried away by water. These are evident (Map 3) at the: 1) northern portion of the lot, which is designated as open space; 2) along the row houses in Block 1, unchanneled runoff flows on the ground; and 3) top layer of the soil at Block 17 (Map 5) is being washed out leaving stones on top and visible small water trails on the soil.

There was no landslides report in the site during Typhoon Ondoy (September 2009), however there was a small landslide that occurred along the road cut of the acquired road right-of-way of PSHAI at the other side of Block 10.

17 Table 3: Geohazard Identification Survey and Geohazard Assessment Findings

GEOHAZARD EXISTING AND CONTRIBUTORY CONDITIONS POSSIBLE IMPACTS RECOMMENDATIONS

Ground vibration during The site is located near earthquake generators,9 the nearest Intense ground shaking can cause The development plan must adapt to the natural topography and avoid an earthquake (lindol) possible source of which is the West Valley Fault that can generate damages to houses, especially if the major changes in the terrain. a magnitude-7.5 earthquake. foundation does not reach the bedrock. Footings of housing units particularly in filled areas should reach the The geologic conditions at the site affect the intensity of ground bedrock to make sure that no settlement or other movements will take shaking felt onsite: ground shaking tends to be more intense in Earthquakes can trigger the place. areas where the underlying soil and rock materials are loose and collapse of cut slopes along not compacted compared to areas underlain by hard, massive boundary lines, especially if the Steep slopes identified (Map 1) should be left as open spaces or bedrocks. slope is wet after continuous rain. developed as parks. Cutting into slopes along boundary lines should not be abrupt; terrace type of slope protection is suggested or if needed, a retaining wall.

Mass movements Heavy and prolonged rainfall can cause moderate to steep slopes The slumps can move down the The development plan must adapt to the natural topography and avoid (pagguho ng lupa) in the with poor physical properties (i.e., loose materials or highly porous valley and affect houses and other major changes in the terrain form of: and permeable soil) to slump or slide. The soil and rock materials structures along the way. get oversaturated (basang basa sa ulan) that these fall or slide The identified steep slopes (Map 1) should be left as open spaces or Slump down suddenly. Uneven ground can lead to developed as parks damages of the house. Small landslides Earthquakes that generate intense ground shaking can trigger small Cutting into slopes along boundary lines should not be abrupt as to landslides along the boundary lines where cutting into the slope promote slides, slumps or topples of loose ground materials. A terrace Differential settlement would leave steep sides (matarik na gulod), especially if these are type of slope protection is suggested or if needed, a retaining wall. left without slope stabilization measures. Backfilling of depressions and low-lying areas must be in accord with existing engineering practice to avoid problems on settlement and Differential settlement can happen in areas where substantial filling is done and where compaction of the fill materials is not properly creeping. For instance, tree trunks, branches, leaves and other done. If the soil is not compressed well and is fully saturated (kung biodegradable materials should not be included in the fill materials, ang lupa ay basing basa at malambot na), parts of the foundation because when decay, they will create voids underneath. Compaction of that was filled up may sink (bababa) under the weight of the house. the fill materials should be done adequately.

Saturated filled areas can also be prone to slumps that can be The footings of housing units, particularly in filled areas, should reach the triggered by intense ground shaking during an earthquake. bedrock to avoid or minimize settlement or other movements. The national building and structural codes for the structural design of houses must be followed.

Erosion and Erosion is occurring in areas where cutting has been done without Erosion leads to sedimentation In order to avoid excessive erosion, earthworks should be done during sedimentation along the compaction and the cut or fill materials are left exposed to the along the drainage system. the dry months and appropriate slope protection measures for soil drainage system action of rain. Erosion may be reduced after the site development stockpiles and cut slopes must be adopted when necessary. will have been completed. (Hazards related to the flow of water)

9 The GIS and the GAR identified five tectonic earthquake generators that may affect the housing site, namely, the West and East Valley Faults, the Philippine Fault Zone (PFZ), the Manila Trench (MT), the Digdig Fault (DF), the Lubang Fault (LF) and the Casiguran Fault (CF). Most of these generators can produce earthquakes with magnitudes greater than 7 that can be result in intense ground vibration.

18 4.a. Reading and responding to signs of slope problems, Blocks 1 to 10: Map 3 Severe erosion occurs in many areas in the site. Though erosion is gradual process and its impacts on human lives and the landscape are not as drastic and devastating as a landslide event, it has a significant cumulative impact of degrading ground conditions in the uplands and sedimentation in lower areas. Overall, there is a need to improve surface drainage and soil management in the housing site.

A small landslide occurred at an exposed vertical roadside cut along Block 6 after heavy rains in August 2009. There is a need to stabilise roadside cuts by planting deep-rooted trees or constructing riprap before houses are to be built above these areas.

Slopes at Block 10 were marked with in the GAR as moderately or steep sloping even for housing site. The slope cut creates sharp sides along the boundary lines that can cause stability problems for the houses that will be built there. The building of houses on this block must wait first for the hilltops on the other side to be removed so that risk would be lessened.

4.b. Reading and responding to signs of slope problems, Blocks 11 to 15: Map 4 The upper concave (mala-malukong) slope above the road in Block 14, which lies outside the lot, poses a threat to the corner lots in Block 14. Prolonged and intense rainfall may cause the slope to collapse that, given enough liquidity, may result in a flow down the gully. The road may or may not hold off landslide materials from the concave slope. At the receiving end are the corner and lower lots of Blocks 14. If the plan for the removal of this concave slope pushes through, the risks for the said areas are reduced.

Block 15 sits on a steep slope below the road. The steep lots (lots 3-10) are not suitable for housing with the “buriable” condition. The GAR also recommends that it be left as open space or developed as a park. Efforts should be focused on strengthening slope stability.

4.c. Reading and responding to signs of slope problems, Blocks 16 to 20: Map 5 Some lots in Block 18 lies in drainage hollow, which can be a high-risk area for Lots 22 to 32 and the designated !park and playground" are unstable sites, thus, the individual lots that have not built on should be reassigned to available safer lots. Existing indicators of slope instability include:

• Unconsolidated soil and rock materials; • Landform on the upper slope indicative of a landslip; and • High water table, as seen in the appearance of spring, short-term pool and seepage.

Below the landslip are two houses right in the middle of where the water flows. The homeowner (Lots 30 and 31) dug small canals around their houses to keep off the runoff that previously would flow through their floors. The canals can

19 contain the small runoff, but the greater risk to the houses is the threat associated with groundwater and seepage.

Groundwater is a critical existing slope conditions that increase the likelihood of landslide. The shallow groundwater, which comes out on the ground as spring and short-term pool gives the benefit of water supply but contributes to initiating slope failure as it reduces the slope!s resisting force and increases the likelihood of oversaturation during heavy rain that can lead to a landslide. As related by one of the homeowners already settled in lower Block 18, “bumubukal ang lupa pag tuloy-tuloy ang ulan.” (Seepage – or water would come out of the porous soils after continuous and intense rains during the rainy season.) It is important for the homeowners to evacuate to the community center when there is prolonged and heavy rainfall, especially if it rained during the previous days or weeks.

The high moisture level of the soil and rock materials reduces the resisting force of the slope and in turn undermines slope stability. Gabi (taro) is a water-loving plant, and is an indicator of high soil moisture. Given the existing moisture level in the area, intense and prolonged rainfall can easily saturate the mass and possibly lead to liquefaction and slope failure.

20 4.d. Cherry Hills Subdivision (Antipolo, Rizal): Revisited after a decade The Cherry Hills tragedy occurred on the night of 3rd August 1999, claiming 58 lives, leaving 32 people injured and one missing. The heavy rains (three consecutive days) of the approaching Typhoon Olga primarily caused the massive landslide. According to PAGASA technical personnel, the area has an average slope of about 20 percent enough to trigger down slope movements of any unstable materials. The nature and character of the materials found in the area were also contributing factors in the incident as well as human intervention in the form of developments directly on the slopes. Based on the Philippine Institute of Civil Engineers (PICE) and Association of Structural Engineer of the Philippines (ASEP), the foundation was filled with water and the whole complex slid down the hill on which the subdivision was built.

Mountainside cut that North collapsed due to water saturation of the slope. Table 3: Photo 1

Table 3: Photo 4

Table 3: Photos 2 & 3

Photo 1: With record level of rainfall (500 mm occurring on 2nd Aug), development of near full hydrostatic pore pressure was possible. Prolonged water saturation and subsequent pore pressure build-up was the final blow that triggered the landslide (Morales, E. et. al., 2001; photo credit: Punongbayan, 1999).

Five months prior to the event, there were repeated signs indicative of ground movements. Cracks were observed in some houses, which continued progressively. It is in this context that the geotechnical team believed that early warnings could have been made thus would have saved lives and injuries. Further, the team believed that there was an error in judgment for approving construction and development to take place in an area such as Cherry Hills.

The Cherry Hills Subdivision is located in Barangay San Luis, Antipolo City, Province of Rizal, (Map 2). It is situated in an elevated terrain cut along the Sierra Madre range. It is bounded by two subdivisions: Park Village to the north and Peace Village to the south. The mountainsides left after the cut bound the east and west. The eastern summit has an elevation of 225 masl while the western

24 side is at 233 masl. The part of the subdivision cut from the eastern mountainside is approximately 26 meters deep.

The 50,000-square meter subdivision is home to about 800 families, paying-off low cost and concrete houses. The land was owned and developed by Philjas Corporation, which is a joint-business between Filipino and Japanese investors. The Philjas Corporation no longer exists and has a pending case with the Philippine Justice Court for gross negligence in the construction, development, and implementation of the Cherry Hills (real estate) project.

Eleven years after the tragic event, the Cherry Hills Subdivision was revisited in order to see if it would be a good site to study “lessons learned” and to compare and contrast with the PSHAI site in San Isidro, Rodriguez, which is also located along the Sierra Madre and Rizal Province.

Table 4: Cherry Hills Revisited, July 2010 (cf Photo 1)

Cherry Hills Subdivision Description Remarks Photo 1: Compared to Miraculous Mountainside area Hills, the slide at Cherry that collapsed in Hills is deeper. This deep August 1999. The cut however was the area where result of the development vegetation are activities in the site. found i.e. banana, Alteration did not follow grass used to be the natural contour and the site of housing left deep cut i.e. 26 but were covered meters the deepest. with mud after the event. PSHAI need to be careful with their plan of slope The homeowners cutting for levelling their planted mahogany site. Critically, they need seedlings provided to consider the by the Antipolo recommendations made City government to by GAR (cf section 5) for help stabilise the site development. slope. Photo 2: Moderate and steep Riprap was slopes (Map 6) identified constructed to at Miraculous Hills are hold soils intact. suggested to remain as No houses were open space. rebuilt above this as the area is Riprap could also be identified high-risk constructed or stacked in (prone to erosion these moderate and and ground steep slopes. movement) after the landslide.

25 Cherry Hills Subdivision Description Remarks Photo 3: Moreover, planting of Sandbags, mostly deep-rooted trees is also covered with suggested. grass, are stacked to prevent soils cf Section 5 for detailed from eroding. discussion.

Photo 4: Critically, PSHAI needs Eroding soils to look into their drainage poorly managed systems to avoid further hence blocking removal of soils due to effective flow of runoff. Runoff also needs water to canal. to be channelled through canals. A Road crack caused by the cf Map 3 and section 5 August 1999 event for detailed discussion. were still evident and is further aggravated by poor drainage management.

The organisation structure is different in a sense that a private corporation developed the land in Cherry Hills while the Miraculous Hills Subdivision is a community-led initiative by the Payatas Scavengers Association. Critically, Cherry Hills is larger in area and has deeper mountainside cut compared to Miraculous Hills Subdivision thus the extent of potential risks or threats are different. Generally, Rizal!s geologic setting is composed of middle Tertiary sediments and Quaternary pyroclastics and lava flows10 but local geologic setting needs further investigation and sampling. The local geology and soils characteristics are important to understand as it gives the local dynamics of the broader landscape. Table 5 shows the characterisation and comparison between Cherry Hills Subdivision (Antipolo City) and Miraculous Hills Subdivision (Rodriguez).

Table 5: Cherry Hills and Miraculous Hills Subdivisions Characterisation

Miraculous Hills Location (Map 2) Cherry Hills Subdivision Subdivision (PSHAI) Province Rizal Rizal Municipality Antipolo City Rodriguez (formerly Montalban)

10 This is the general composition of the Central Luzon Plain, which is unconformably overlying Cretaceous to Lower Tertiary basement rocks. Pyroclastics are rocks primarily composed of volcanic materials where have been transported and reworked through mechanical action, such as by wind or water. Possible sources for these are: Mt. Arayat (Pampanga), Mt. Makiling (Laguna) and Mt. Taal (Batangas).

26 Miraculous Hills Location (Map 2) Cherry Hills Subdivision Subdivision (PSHAI) Barangay San Luis San Isidro Description Land area 50,000 square meters 30,000 square meters Members About 130 (existing) 317 Type of housing Low-cost housing, private Low-cost housing, developer owned community-owned Site planning and Private developer initiated Community-led (PSHAI) in development their first project with no coordination with HPFPI/ previous track record PACSII Geophysical Elevation range 170 – 200 masl 45 to 95 masl Watershed Cogeo, 19.1 sq km Puray, 35.6 sq km Geology Regional Composed of Tertiary sediments and Quaternary pyroclastics and lava flows Local Guadalupe formation, Table 2 Soils Regional The rolling surface suggests that erosion played a part of its origin. Generally, volcanic tuff, a parent material that is a product of geologically recent eruptions of volcanoes is found in the surrounding provinces of Manila. Local Terrace gravel with assorted rock fragments and limestone-rich fragments Rainfall pattern Annual average: 1,500 to 2,250 millimeters – during Central Plain of southwest monsoon (habagat) the plain is shielded by Luzon Zambales Mountain, which lie directly to the west while during northwest monsoon (amihan) the plain is shielded by Sierra Madre situated to the east.

The Cherry Hills tragedy might have been prevented only if the company had experience in construction and if there was proper site planning and development. However, at that time, there was no set requirements or procedures that assess the land suitability and geohazards of a site.

The tragic event of Cherry Hills put the credibility of technical institutions such as the MGB in question. Many geotechnicals contested the development of Cherry Hills, however, these were made after the landslide event. Hence, the government set a standard procedure (DENR DAO 2000-33) of the need to conduct geohazard assessment prior to site development. Following the assessment is the development of a Geohazard Assessment Report (GAR) that basically includes:

1. Executive Summary (of the report) 2. General information (of the site) 3. Project description: with site plan, location, and accessibility 4. Assessment and methodology 5. Geological investigation: regional setting, geomorphology, climate, etc. 6. Findings and observations 7. Comments and recommendations

27 It is critical for communities and local government to adhere to the recommendations of GAR. Local government or other approving bodies must integrate the GAR in their broader landuse plan and in site development thus not seeking more for a higher density of housing than safer housing.

28 5. Strategy and community action plan Generally, the people!s perception of risks in the site is limited in a sense that their understanding on the possible danger of ephemeral (panandalian) streams and moderate and steep slopes are minimal. Residents would recall a gully becomes a creek or river only when there is water flow during rainy season. Otherwise, the gully is dry and will not pose threats. However, the people need to understand that when it rains heavily for days, it is not just the volume of water as runoff but the soils in the concave slope above Block 14 than can become mobile or the groundwater on lower Block 18 that can cause the slope to liquefy (Map 6). Although there has been no major landslide report over the last eight years since they lived in the site however eight years does not give an adequate temporal perspective to know their landscape history. Major events are measured or projected over a 50-year projection, which could occur any time form year 1 to year 50.

Since PSHAI are new to the site and lack historical knowledge of landslide events in their relocation site, the assessments conducted are an important source of information on the potential risks in their new site, which could be their starting point in building their knowledge of their site. Site planning and development must avoid aggravating the existing geohazards.

Significantly, the recent slump on a roadside cut in Block 6 (Map 6) made the people aware that it is dangerous to build above it.

PSHAI identified three reasons for re-blocking and revision of individual lot allocation:

1. To enhance the human security of current and future homeowners in potentially problematic areas thus avoid the possible loss of life and damage to property;

2. To comply with the provisions of the Environmental Compliance Certificate (ECC) issued to the housing project; and

3. To avoid congestion as recommended by the Housing and Land Use Regulatory Board (HLURB).

Consequently, PSHAI with HPFPI-NCR is seeking the assistance of the Rodriguez municipal engineer office to conduct the cadastral survey for the individual lots with the intention of revising the site plan to incorporate the above objectives.

Strategically, to avoid future congestion, members who have the capacity to pay are suggested to take the lot or lots adjoining their assigned lots that are not yet taken. However, they will be allowed to build only one house on their widened lot thus this may be limited to few areas.

The nine lots in Block 15 (Map 6) that are not yet built on will be retained as an open space. The assigned members will be transferred to other safer areas that are vacant as some members backed out because they decided to return to their province or have other opportunities for acquiring lots elsewhere.

The owner of the house in lower Block 18 (Map 6) signified her willingness to transfer to an unoccupied unit at the row house. Yet she has to formally communicate her interest through the PSHAI officers. Another member, who fears

29 that her housing lot where seepage emerges from the ground during continuous rainfall may also be prone to landslide, would like to know how the association would address her situation. The three families who have already built their houses in the said area need to be ready for necessary precautionary measures. PSHAI respects the decision of the owner of the single house in Block 15 to remain where his house is. It is important that he has been told about the risks hence do his part to ensure the safety of his families. He needs to be observant of danger signs in his surroundings and always be prepared to evacuate his family when there is continuous and prolonged rainfall.

There seem to be no immediate plans of the members assigned to Block 10 and upper Block 18 (Map 6) to build their houses, and they may just wait until the remaining hillslopes on the nearby lot are removed.

Significantly, PSHAI is consulting with different technical groups and individuals as to how to develop and manage their site. Aside from ESSC, PSHAI also engaged with individual and or groups of engineers and architects for (as much as possible) pro-bono consultations.

30 5.a. Recommendations Drainage and erosion management: Doable actions to help stabilise slopes and reduce surface erosion

Planting fruit trees with deep roots like langka (Artocarpus heterophylla), santol (Sandoricum koetjape), sampaloc (Tamarindus indica), and avocado (Persea americana) can help stabilise soils. These fruit-bearing trees give the added benefit of food. Compared to langka and santol, mango (Magnifera indica) Use of sandbagging to and coconut (Cocos nucifera) can be retain the soil. more easily toppled by strong winds.

Repair drainage canals (cf 4.a and Map 3, along the row houses in Block 1).

Leave ground cover when cleaning the roadsides of herbaceous and wood growth is necessary, trimming is enough.

Maintenance of roads and pavements

Along some road edges the soil underneath the concrete is washing out weakening the concrete and these areas need to be built up.

A long crack along one side of the road near Block 3 indicates that the foundation is not solid. This might be due to the passage of water under the concrete across the road as the drainage on the other side is clogged with eroded soil. The cracked side is losing its soil foundation along its edge. The weight of heavy trucks might also be adding weight on the concrete.

Road maintenance include:

• Building up with rocks and gravel so as to prevent the loss of soil under concrete roads and pavement to stabilise the foundation.

• Digging and maintaining roadside drainage canals to reduce the runoff passing over the concrete.

• Using gravel rather than soil when improving the access road going to the housing site. Drainage canals should be dug to divert runoff from the road. Water made deep cuts through some parts of the road.

• Stabilisation of road cuts through vegetative cover or riprap.

Site planning and development based on the Geohazard Assessment Report (GAR)

32 The GAR recognised that the entire lot is not critical for housing but necessary mitigation measures must be taken to address the existing hazards in the area, Map 6:

1. As much as possible, topographic alteration should be subtle: the development plan should adapt to the existing topography and not the other way around.

2. It is strongly suggested that steep slopes should be left as open spaces or developed as park to avoid problems in the future.

3. In altered areas (Block 10 and upper portion of Block 18), the final grade line should have gentle slopes to prevent mass movements such as slumps and slides.

4. Cut slopes along boundary line (Maps 3 and 4) should not be abrupt as to promote slides, slumps or topples of loose ground materials. A terrace type of slope protection is suggested or if needed, a retaining wall.

5. To avoid excessive erosion, earthworks should be done during dry months and appropriate slope protection measures for soil stockpiles and cut slopes be adopted when necessary.

6. Backfilling of depressions and low-lying areas must be in accord with existing engineering practice to avoid problems on settlement and creeping. Filling should not include tree trunks, branches, leaves, grasses, etc. that when degraded, will leave voids underneath. Adequate compaction should be carried out religiously.

7. If possible, footings of housing units particularly in filled areas should reach the bedrock to make sure that no settlement or other movements will take place.

8. When applicable, structural design of units should follow the national building and structural codes of the country.

33 6. Good practices: soil erosion management AGROFORESTRY is a land management system that involves mixed cropping and where annual (taunan) and perennial (pangmatagalan) crops are combined sequentially (sunud-sunod) or simultaneously (sabay-sabay). The effort is to enhance the productive and protective capacity of the land by improving the socio- economic condition of the dwellers and rehabilitating degraded upland areas. Additionally, livestock raising is included in the system for supplementary income and protein source for people. In the Philippines, agroforestry is a strategy to both rehabilitate denuded areas and provide a source of livelihood for upland farming communities.

The agroforestry system provides great potential in developing sustainable management alternatives for crop production in steep lands. In the case of Miraculous Hills, where there is minimal crop production on steep areas i.e. Block 9, the system is valuable for erosion control and management and potentially, with appropriate management, could generate additional income and food source for the association.

Predominant soil erosion processes that occur in steep areas are rill (sapa- sapaan) and gully (kanal) erosion. These processes are associated with rainfall intensity (lakas ng ulan), velocity of surface runoff (bilis ng agos ng tubig), and soil characteristics (katangian ng lupa). The risks may be minimised through biological techniques and/or engineering techniques.

Erosion control can be undertaken through planting vegetative cover and include not just trees but also shrubs and grasses. Below are the requirements for suitable species selection for soil erosion control: (Agpaoa, A., et. al., 1976)

• The species must be able to succeed on degraded sites; • It should have a deep and wide spread root system; • It should be able to improve the soil conditions by producing plenty of litter and are nitrogen fixing species; • The species must be able to withstand drought followed sometimes by abundance of water; and • The species should give some economical returns like lumber, fuelwood, edible fruits, or other useful products.

For lower elevations like Miraculous Hills bamboos (family: Poaceae) and leguminous species like kakawate (Gliricidia sepium) and ipil-ipil (Leucaena leucocephala) are recommended.

Typical agroforestry systems are presented, which could be implemented at Miraculous Hills (specifically at Block 9):

1. Mixed-cropping system. This system combines bamboo (family: Poaceae), forest species, fruit trees (deep-rooted trees in the case of Miraculous Hills), root crops or medicinal plants arranged in a multi-layered canopy. The bamboo occupies the main canopy layer while the middle or intermediate can be planted with developing forest trees like mahogany – large leaf (Swietenia macrophylla), fruit trees like langka (Artocarpus heterophylla), santol (Sandoricum koetjape), sampaloc (Tamarindus indica), and avocado (Persea americana). The lower layer can be

34 composed of cassava (Manihot esculenta), pineapple (Ananas comosus), and ginger (Zingiber officinale).

a. Technically, bamboos are spaced 8 x 8 meters to allow enough light to reach the lower vegetation and at the same time keep soils from eroding.

b. A year after planting bamboos, planting of mahogany is suggested. Mahogany is better than planting acacia (family: Fabaceae). Acacia provides shades however its root systems are too shallow thus pose higher risk of erosion. Mahogany plantation could be a long- term investment for the community since it is a valued source of non-timber products such as sawnwood. Normally, mahogany takes 30 years before it fully matures and ready for harvest however, thinning can be initiated on 15 or 20-year.

Large leaf mahogany thrives under rainfall from 1500 to 5000 millimeters and a dry season up to five months. Trees are taller and grow faster in moist climate but the quality of dry area mahogany is superior.

c. Deep-rooted fruit trees provide food and at the same time hold soils thus minimise erosion. They also provide good shade and considerate amount of litterfall (mga dahon or sanga nalalanta mula sa puno) that adds to ground cover and nutrients.

d. Root crops suggested to be planted at the lower portion to reduce removal of soils from slope areas considering that its tillage and cultivating practices result to moving of soils downslope.

Significantly, this system promotes ecological balance and at the same time supports local economic activities.

2. Alley cropping involves the establishment of hedgerows of trees or shrubs (usually double-hedgerows) at regular intervals along the contours and the planting of agricultural crops in the open space or alleys formed between the hedgerows. The contours are usually 4 to 6 meters, depending upon the steepness of the slope. It is closer in steeper slopes and wider in flatter ones. The hedgerow species are usually leguminous trees that minimise soil erosion, reduce surface runoff, and improve soil fertility. Usually, vetiver (Chrysopogon zizanioides), kakawate or madre de cacao (Gliricidia sepeium), malabalatong (Flemingia congesta), ipil-ipil (Leucena leucocephala) and rensonii (Desmodium rensonii) are used as hedgerows. These plants and other nitrogen fixing plants are good to hold soils as well as nutrients especially when cut and laid along the contour line.

The hedgerows should be pruned back to the height of about 0.50 meters to minimise shading of agricultural crops in the alleys. The frequency of pruning depends upon the coppicing or sprouting ability of the species. Biomass from the prunings can be mulched (compost), used as green manure (pataba) or as a fodder (pagkain) for the livestock. The ideal characteristics of the hedgerow species are easy to establish, fast-

35 growing, good sprouting or coppicing ability, nitrogen fixing, deep rooted and with multiple uses. (Gascon, et.al, 2006).

a. The vetiver grass has been planted at Miraculous Hills thus in order to maximise its potential, there is a need to assess the area where it is planted.

Vetiver grass or khus khus has a unique rooting system that binds loose soil to prevent surface erosion. Its long growth anchors the soil as deep as three meters – the roots of the vetiver grow one foot every month until they reach three meters on the ninth month. It has been used for centuries to mark boundary lines. Its roots and tops are also harvested; the fragrant, insect-repelling roots yield oil, which is valuable in the perfume industry. Traditionally, the roots are woven into mats, fans, and fragrant screens, while the tops of the grass are used for handicraft, thatch, mulch, fodder and animal bedding (http://www.derm.qld.gov.au/factsheets/pdf/land/l34.pdf).

b. Kakawate or madre de cacao is common in the Philippine lowlands. It can be easily established on dry and poor sites by cuttings, and is useful for erosion control at lower elevations. It is also capable of improving soil conditions because of the high nitrogen content of its leaves. Generally, it is used as live fencing, coffee shade, firewood, green manure, and rat poison. It is also used for medicinal and insect repellent; the extract from leaves is used to remove external parasites.

c. Malabalatong and rensonii are commonly used for erosion control. They are also used to shade coffee and cocoa plants, for weed suppression and soil enrichment in orchards, and provide fuel wood. Pods (balat ng buto) provide a brilliant orange dye for silk. Malabalatong thrives better than rensonii.

36 7. Points to consider in building eco-settlement site A housing site that is managing the slopes, drainage and other natural conditions existing in a place is fundamental for having eco-efficient settlements. Allocating proper uses for different slope conditions is a prudent strategy towards building a safe community, as well as a practical and efficient way of using available resources.

Economically, it makes practical sense to efficiently use the resources of the members of a housing organization. Building a house in a slope with high landslide potential will not only endanger lives but can also put to waste the well- earned savings of low-income association members. A landslide or slope failure that results in the partial or total destruction of a house wipes away not only houses but can also lead to injuries and even fatalities. It can also mean additional investments that may be needed for keeping slopes stable, such as constructing sturdy ripraps to support the cut along the boundary line.

Further, building houses on a moderate to steep slope will put pressure on the slope that will bear the additional weight of the house and on the slope above the cut area. Not building on slopes can entail higher initial costs but can be cost saving in the long term as potential losses and damages are avoided.

Ecologically, planting firmly-rooted trees and leguminous species on slopes helps in soil conservation and slope stability. Agroforestry is a recommended strategy that could help enhance the protective capacity of the land and at the same time improve productivity and diversify the community!s livelihood source.

Critically, there is a need to seek for further research for the community to be productive and sustainable and make them self-reliant. Vetiver along with common leguminous trees or shrubs offers a starting point for exploring a wide range of hedgerow (halamang-bakod) species that can be used for protecting soil cover and nutrients and at the same time source of food and further economic activities for the community.

37 REFERENCES Agpaoa, A. et. al., (1976). “Manual of reforestation and erosion control for the Philippines,” compiled by H.J. Weidelt. GTZ, Eschborn.

Environmental Science for Social Change (2009). “Site Assessment Report: Miraculous Hills Subdivision – PSHAI, Rodriguez, Rizal.” ESSC-Quezon City: Field Report.

“Future Master Development Plan Rodriguez (Montalban), Rizal. http://www.acerhomes.com/rizal_future_devplan.html

Gascon, E., et.al., (2006). “ Agroforestry Systems in the Philippines: Experiences and Lessons Learned in Mt. Banahaw, Hanunuo Mangyan, and some Community-based Forestry Projects.” http://www.plant- trees.org/resources/infomaterials/english/country_specific/Agroforestry%20Systems%2 0in%20the%20Philippines.pdf

Geo Environmental Consultancy, Inc. (2004). “Geohazard Assessment Report: Payatas Scavengers Housing Project,” in compliance to the requirement of DENR Administrative order No. 2002-28.

Lal, R. (1990). “Agroforestry systems to control erosion on arable tropical steeplands,” Proceedings of the Fiji Symposium on Research Needs and Applications to Reduce Erosion and Sedimentation in Tropical Steeplands, June 1990. http://iahs.info/redbooks/a192/iahs_192_0338.pdf

Morales, E., et.al. (2001). “The Cherry Hills Landslide Tragedy,” paper presentation at the 2nd Civil Engineering Conference in the Asian Region, Tokyo.

Municipal Government of Rodriguez (1998). “Comprehensive Development Plan of Rodriguez,” developed through the assistance of Santamaria Planning and Research, Inc.

38 Annex 3: Households by Type of Building, Kind of Toilet Facility Used, Municipality of Rodriguez (1990)

Kind of Total Single Duplex Multi-unit Commercial Institutional Other Not Toilet Households House Residential /Industrial/ Living Housing Reported Facility (3 Units or Agricultural Quarters Unit More) Total 12 891 10 193 1 008 1 597 73 20

Water- 6 468 5 056 714 660 28 10 sealed, Sewer/Septic Tank, Used Exclusively by the Household 1 764 1 130 69 547 8 10

Water- sealed, Sewer/Septic Tanks Shared With 986 786 39 124 37 Other Households

Water- sealed, 536 325 97 114 Other Depository Used Exclusively by the 1 118 1 018 20 80 Household 818 776 42 Water- sealed, 74 74 Other Depository Shared with 1 127 1 028 69 30 Other Households

Closed Pit

Open Pit

Others (Pail System, etc.)

None Source: 1998 Comprehensive Development Plan of Rodriguez. Figures are estimates based on a 10 percent sample.

41 Annex 4: Households by Type of Building, Main Source of Drinking Water, Municipality of Rodriguez (1990)

Main Source of Total Single Duplex Multi-unit Commercial Institutional Other Not Drinking Water Households House Residential / Industrial/ Living Housing Reported (3 Units or Agricultural Quarters Unit More) Total 12,891 10,193 1,008 1,597 73 20

Own Use, Faucet, 3,257 2,685 341 213 18 - Community Water System

Shared, Faucet, Community Water 2,446 1,673 224 530 9 10 System

Own Use, Tubed/Piped 2,290 1,729 156 359 46 - Deep Well

Shared, Tubed/Piped 2,886 2,204 247 425 10 Deep Well

Tubed/Piped Shallow Well 258 148 40 70

Dug Well 432 432 Spring, Lake, River, Rain, Etc. 1,322 1,322 Peddler Source: 1998 Comprehensive Development Plan of Rodriguez. Figures are estimates based on a 10 percent sample.

Annex 5: Households by Type of Building, Fuel Used for Lighting, Municipality of Rodriguez (1990)

Fuel, Used for Total Single Duplex Multi-unit Commercial/ Institutional Other Not Lighting Households House Residential Industrial/ Living Housing Reported (3 Units or Agricultural Quarters Unit More) Total 12,891 10,193 1,008 1,597 73 20

Electricity 9,484 7,012 902 1,495 65 10

Kerosene 3,268 3,073 106 81 8

Liquified 109 88 21 Petroleum Gas (LPG)

Oil (Vegetable, 20 20 Animal, etc.)

Others 10 10 Source: 1998 Comprehensive Development Plan of Rodriguez. Figures are estimates based on a 10 percent sample.