Professorial Chair Lecture

Manila Rivers and Esteros: Imagery and Engineering by Leonardo Q. Liongson, PhDUPAE Professor of Water Resources Engineering

sponsored by Department of Civil Engineering and National Hydraulic Research Center College of Enginering, U.P. Diliman

9-10 a.m., June 29, 2000 MH 237 (Hydraulics Seminar Room) NHRC, Melchor Hall - College of Engineering University of the Philippines, Diliman

Objectives and scope of the lecture

• To report on previous and present status of Manila rivers and esteros with regard to flood control capacities;

• To present past and present engineering measures to improve river conditions to support varied human uses.

• Photographic and graphical imageries

• Hydrologic and hydraulic data and engineering plans

• Results of analysis and modeling

• Specific projects

METRO-MANILA:

Meycauayan (until early 1980s)

Kamanava: Kalookan,Malabon, Navotas, Valenzuela

Manila Quezon City, Marikina, San Juan, Mandaluyong, Pasig,

Makati, Pateros, Pasay, Taguig,

Parañaque,Las Piñas, Muntinlupa.

Metro-Manila Rivers and Esteros:

Name of River Basins Drainage Area (sq.km.)

Marikina RB 535Mangahan Floodway-Taytay RB 63Taguig-Napindan RB 45

Meycauayan RB 169Obando-Malabon-Navotas Estuary 35

Novaliches Reservoir-Tullahan RB 72San Juan RB 94Pasig RB (north and south) 91

Parañaque-Las-Piñas RBs 73Zapote-Bacoor-Imus RBs 168

Source: NHRC

Flood sectors:

Meycauayan RB

Malabon-Tullahan RB

San Juan RB

Marikina RB (upper)Pasig-Marikina FloodplainPasig RB: North Manila South Manila

Napindan-Mangahan RB

Source: NHRC

The Esteros of Manila (Pasig RB)

North Manila South Manila • (north exit: Manila Bay)

• Estero de Sunog Apo• Estero de Vitas• Estero de la Reina• Estero de Binondo• Estero de Magdalena• Estero de San Lazaro• Estero de San Miguel• Estero de Sampaloc• Estero de Valencia• (south exit: Pasig River)

• (north exit: Pasig River)

• Estero de Balete• Estero de Pandacan• Estero de Paco• Estero de Sta. Clara• Estero de Tripa de

Gallina• Kalatagan Creek• Dilain Creek• (south exit: Parañaque

River)

North Manila (Pasig RB)

(north exit: Manila Bay)

Estero de Sunog ApoEstero de VitasEstero de la ReinaEstero de BinondoEstero de MagdalenaEstero de San LazaroEstero de San MiguelEstero de SampalocEstero de Valencia

(south exit: Pasig River)

Manila map in 1898: the extent of esteros in blue.

Estero de Binondo:Top left: in 1900.Top right: in 1999Left: Garbage at BinondoPumping Station

A cleaner stretch of Estero de Binondo viewed from Blanco Bridge, Feb. 1999

Another cleaner stretch alongEstero de la Reina in Binondo,Feb. 1999.

Government’s Response to MM Flooding Problem(Source: DPWH)

• Mangahan Floodway & Napindan Hydraulic Control Structure

• Effective Flood Control Operations System (EFCOS)

• Flood Pumping Stations and Floodgates• Maintenance & Rehabilitation Programs/ Activities

• Bantay Estero Teams• Mobile Flood Mitigation Equipment

Metro-Manila Area Flood Needs and Responses(Source: DPWH)

Total Metro-Manila Area: 63,600 has.Flood-prone Areas: 10,600 has.

Kamanava: 4,000 has.Central MM: 5,500Upper Marikina: 600 North Laguna Lakeshore 500

Coverage of Flood Mitigation Facilities:Pumping Stations (PS):

15 large & 6 medium PS: 5,300 has.18 small PS 200 has.

Flood Conduits/Waterways:Esteros & creeks 290 km.Drainage mains 44 km.Drainage laterals 1,200 km.Mobile flood equipment 130 has.Mobile flood watch teams 4,970 has.

Major Pumping Stations Pump Capacities Drainage Area (Source: DPWH) (cu.m./s) (hectares) 1. Vitas PS 32 5782. Binondo PS 11.6 2793. Escolta PS 1.5 (included with Binondo)4. Quiapo PS 9.5 2255. Aviles PS 14.1 3566. Valencia PS 10.5 2467. Balut PS 2 49

8. Pandacan PS 4.4 1809. Paco PS 7.59 18210. Sta. Clara PS 5.3 13311. Balete PS 2.5 5212. San Andres PS 19.0 35613. Makati PS 7.0 15114. Libertad PS 42.0 77915. Tripa de Gallina PS 56.0 1,769

Total 224.99 cms 5,335 has

Name of Annual Average Volume ofPumping Stations Garbage Collected/Disposed (1997-1998) (cubic meters)1. Vitas PS 6702. Binondo PS: 1,3023. Escolta PS 744. Quiapo PS 8005. Aviles PS 2106. Valencia PS 614

7. Pandacan PS 7288. Paco PS 6929. Sta. Clara PS 32410. Balete PS 9311. San Andres PS 16212. Makati PS 2813. Libertad PS 3,92214. Tripa de Gallina PS 3,20015. Buendia PS 2,118

Total 14,934 cu.m./yr = 41 cu.m./day

EFCOS: Effective FloodControl Operations System

Source: DPWH

EFCOS: Effective Flood Control Operations System(located in Metro-Manila & Rizal province)

• Aims to achieve an effective flood control operation for Pasig-Marikina-Laguna Lake Complex through

• real time rainfall and water level data collection at the Rosario Master Control Station via telemetry system;

• the effective use of the warning system along Mangahan Floodway; and

• the multiplex communication system among Rosario MCS, Napindan HCS, DPWH Central Office and PAGASA Data Information Center.

The Mangahan Floodwaydiverts floodwaters ofMarikina River to Lagunade Bay.

The Napindan HydraulicControl Structure (NHCS)regulates flow between Pasig River and the lakevia the Napindan Channel

The navigation lock of the NHCS allows water trafficbetween Pasig River andLaguna de Bay through theNapindan Channel.

Pasig River Rehabilitation Program (PRRP)(Source: Pasig River Alive! by Riverwatch, Unilever,1998)

Goal: to improve the water quality of Pasig River by year 2008through the following means:

• eliminating the offensive dry-season odor;

• reducing the BOD from 330 m.tons/day (1991) to 200 m.tons/day;

• reducing the amount of solid waste dumped into the rivers and creeks, and regularly removing floating solid wastes from navigable portions of the Pasig and its main tributaries;

• increasing and controlling the flow of water in the Pasig during the dry season.

Pasig River Rehabilitation Program (PRRP)The Positive Results as of 1998

• Water Quality Improvement:• BOD reduction: 330 m.t./day (1991) ==> 230 m.t./day (1993)

• Needed to sustain aquatic life: < 200 m.t./day BOD

• 1990: 45% domestic liquid, 55% industrial waste

• 1998: 60% domestic liquid, 40% industrial waste

• solid waste proportion: reduced from 10% to 5%

• Partners’ Performance: • Philippine Coast Guard: hauled 116,676 cu.m. garbage from the rivers in

1994;

• MMDA and its partners: collected 1711 cu.m. rubbish in 1994;

• 75 firms (59 inside river basin): BOD reduction of 34.5 m.t./day in 1997.

PCAMRD-LLDA-NHRC BAYWATS Models: watershed hydrologic model, 1-d river networkhydraulic model and 2-d lake hydrodynamic model with management functions (1998-2000).

Types & Causes of rain-induced floods

• Local flooding (flooding by temporary accumulation of undrained water on road surfaces, urban lots, farm lands and other open spaces due to excessive local rains)

• River flooding (overflow of water from major channels into adjoining banks and floodplains)

• High rainfall intensity of long duration (thunderstorms, monsoons, typhoons)

• Impervious surfaces (asphalt and concrete pavements, roofs)

• Flat topography• Inadequate road drainage design-

capacity (curbs, culverts)• Clogging of road drainage by garbage

and other debris• Obstruction or encroachment of small

natural ditches and creeks.

• Large tributary and overland inflows• High tide and storm surge at the

downstream reaches; land subsidence• Channel narrowing by property

encroachment (loss of waterway)• Siltation with sediment, garbage and

other debris• Downstream flow obstruction by bridge

log-jams, debris and other constrictions

Flood Mitigation Measures

• Structural Measures (hardware & construction: upstream (u/s) downstream (d/s))

• Non-structural Measures (software & community-based)

• Dams, spillways & reservoirs; sabo & check dams (u/s)

• Roadway curb inlets, culverts, drop-shafts (u/s)

• Dikes, levees, super levees (d/s)

• River walls & revetments (d/s)

• Floodways (open, underground) (d/s)

• Bridges & viaducts (elevated, overflow) (d/s)

• River widening & dredging, cut-off channels (d/s)

• Pumping stations, garbage screens (d/s)

• Flood gates, storm barrage or barrier (d/s)

• Watershed, floodplain & coastal management (soil, forest, flora, fauna, wetlands, local communities)

• River protection & preservation (people’s participation)

• Flood forecasting and warning (telemetry, computers & telecommunications, sirens, traffic mgmt.)

• Flood evacuation, rescue & relief (housing, health, food)

• Land-use & zoning plans (open spaces, lagoons)

• House/building rainwater collection & infiltration facilities

• Municipal building-code enforcement, flood proofing

• Flood Insurance