The document summarizes the status of Manila rivers and esteros, past and present engineering measures to improve conditions, and ongoing projects. It discusses flooding issues in Metro Manila, names and drainage areas of river basins, the extensive estero system historically and currently, and government responses including pumping stations, rehabilitation programs, and hydrologic modeling. Structural and non-structural flood mitigation measures are also outlined.

1. Professorial Chair Lecture Manila Rivers and Esteros: Imagery and Engineering by Leonardo Q. Liongson, PhD UPAE 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

3. 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.

4. Metro-Manila Rivers and Esteros: Name of River Basins Drainage Area (sq.km.) Marikina RB 535 Mangahan Floodway-Taytay RB 63 Taguig-Napindan RB 45 Meycauayan RB 169 Obando-Malabon-Navotas Estuary 35 Novaliches Reservoir-Tullahan RB 72 San Juan RB 94 Pasig RB (north and south) 91 Parañaque-Las-Piñas RBs 73 Zapote-Bacoor-Imus RBs 168 Source: NHRC

5. Flood sectors: Meycauayan RB Malabon-Tullahan RB San Juan RB Marikina RB (upper) Pasig-Marikina Floodplain Pasig RB: North Manila South Manila Napindan-Mangahan RB Source: NHRC

7. North Manila (Pasig RB) (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)

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

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

19. A cleaner stretch of Estero de Binondo viewed from Blanco Bridge, Feb. 1999 Another cleaner stretch along Estero de la Reina in Binondo, Feb. 1999.

24. 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: 5,500 Upper 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.

25. Major Pumping Stations Pump Capacities Drainage Area (Source: DPWH) (cu.m./s) (hectares) 1. Vitas PS 32 578 2. Binondo PS 11.6 279 3. Escolta PS 1.5 (included with Binondo) 4. Quiapo PS 9.5 225 5. Aviles PS 14.1 356 6. Valencia PS 10.5 246 7. Balut PS 2 49 8. Pandacan PS 4.4 180 9. Paco PS 7.59 182 10. Sta. Clara PS 5.3 133 11. Balete PS 2.5 52 12. San Andres PS 19.0 356 13. Makati PS 7.0 151 14. Libertad PS 42.0 779 15. Tripa de Gallina PS 56.0 1,769 Total 224.99 cms 5,335 has

26. Name of Annual Average Volume of Pumping Stations Garbage Collected/Disposed (1997-1998) (cubic meters) 1. Vitas PS 670 2. Binondo PS: 1,302 3. Escolta PS 74 4. Quiapo PS 800 5. Aviles PS 210 6. Valencia PS 614 7. Pandacan PS 728 8. Paco PS 692 9. Sta. Clara PS 324 10. Balete PS 93 11. San Andres PS 162 12. Makati PS 28 13. Libertad PS 3,922 14. Tripa de Gallina PS 3,200 15. Buendia PS 2,118 Total 14,934 cu.m./yr = 41 cu.m./day

27. EFCOS: Effective Flood Control Operations System Source: DPWH

29. The Mangahan Floodway diverts floodwaters of Marikina River to Laguna de Bay. The Napindan Hydraulic Control Structure (NHCS) regulates flow between Pasig River and the lake via the Napindan Channel The navigation lock of the NHCS allows water traffic between Pasig River and Laguna de Bay through the Napindan Channel.

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