Table of Contents

Volume 5. Baras Sub-Basin ............................................................................... 3

Geographic Location .................................................................................................... 3

Political and Administrative Boundary .......................................................................... 4

Land Cover .................................................................................................................. 5

Sub-basin Characterization and Properties .................................................................. 7

Drainage Network .................................................................................................... 7

Sub sub-basin properties ......................................................................................... 9

Water Quantity ........................................................................................................... 10

Stream Flow ........................................................................................................... 10

Water Balance ....................................................................................................... 10

LIST OF FIGURES

Figure 5-1 Geographical Map .................................................................................................. 3 Figure 5-2 Political Boundary ................................................................................................... 5 Figure 5-3 Land Cover Map ..................................................................................................... 6 Figure 5-4 Drainage Map ......................................................................................................... 8 Figure 5-5 Sub-sub basin Map of Baras Sub-basin................................................................. 9 Figure 5-6 Annual Stream flow (1990 – 2004) ....................................................................... 10 Figure 5-7 Water Balance Percentage (1990 – 2004) ........................................................... 11

LIST OF TABLES

Table 5-1 Geographic extent ................................................................................................... 4 Table 5-2 Municipalities covered ............................................................................................. 4 Table 5-3 Land cover and Area ............................................................................................... 6 Table 5-4 Drainage Properties................................................................................................. 7 Table 5-5 Baras Sub sub-basin properties .............................................................................. 9 Table 5-6 Water Balance ....................................................................................................... 10

Technical writer

Mr. Manuel V. Quinto, LLDA-PDMED

Technical editors Ms. Adelina C. Santos-Borja Officer-In-Charge Resource Management and Development Officer

Engr. Emiterio C. Hernandez Officer- In Charge Project Development Management and Evaluation Division

Map production

Mr. Neil V. Varcas, LLDA-PDMED

Volume 5. Baras Sub-Basin Geographic Location The Baras sub-basin comprises the municipality of Baras and some barangays from the municipality of Morong and Tanay. The Marikina sub-basin bound it on the north, on the east is the municipality of Tanay, the municipality of Morong in the west, and the Laguna de Bay on the south (Table 5-1). The center of the sub-basin is defined by coordinates 121°16”12.63 E and 14°32”8.48” N.

Source: LLDA GIS

Figure 5-1 Geographical Map

Table 5-1 Geographic extent

Source: LLDA GIS

Political and Administrative Boundary The Baras watershed is bounded by the municipality of Baras and parts of Morong and Tanay as seen in Figure 5-2. The watershed has 12 barangays namely, Evangelista, Rizal (Poblacion), San Jose, San Salvador, Concepcion, San Juan, San Miguel, Mabini, and Pinugay in the municipality of Baras, Barangay Lagundi in Morong and Barangay Cuyambay and Plaza Aldea in Tanay. It has a total area of 22,143,694.74 hectares, in which around 83% is composed of the nine barangays of Baras while 16% comprises parts of the two Barangays of Tanay and the rest is located in parts of Barangay Lagundi of Morong. Table 5-2 shows the summary of the barangay within the watershed with its respective area and percentage.

Table 5-2 Municipalities covered

Municipality Barangay Area (sq.m.) Percentage

Baras San Jose 2,307,719.63 10.42%

Evangelista 1,551,438.24 7.01%

Mabini 724,167.73 3.27%

San Salvador 376,500.36 1.70%

San Miguel 3,863,440.62 17.45%

Concepcion 1,804,482.99 8.15%

Rizal (Pob.) 1,943,092.80 8.77%

San Juan 1,610,566.15 7.27%

Pinugay 4,126,171.38 18.63%

Subtotal 9 18,307,579.89 82.68%

Tanay Cuyambay 2,885,567.75 13.03%

Plaza Aldea (Pob.) 641,680.35 2.90%

Subtotal 2 3,527,248.10 15.93%

Morong Lagundi 308,866.75 1.39%

Subtotal 1 308,866.75 1.39%

Total 12 22,143,694.74 100.00% Source: LLDA GIS

CORNERS NORTHING (UTM) EASTING (UTM)

Upper Left 1604140.50000 312247.81250

Upper Right 1604140.50000 316606.46875

Lower Right 1613484.75000 316606.46875

Lower Left 1613484.75000 312247.81250

Source: LLDA GIS

Figure 5-2 Political Boundary

The total population in Baras watershed was estimated by the summation of the total population of Baras municipality, Barangay Lagundi in Morong and Barangay Tandang Kutyo in Tanay. Baras had a population of 24,514 per the year 2000 census. Barangay Lagundi, Morong, had a population of 6,889 or 16.21 percent of the total municipal population during the same census year. In the Tanay portion of the watershed, Barangay Tandang Kutyo had a population of 12,789 or 16.33 percent of the total population of the municipality in the same census year. In the year 2000, the total population of the watershed is 44,183. Land Cover There are six classes of land cover in Baras sub-basin (urban, arable, plantation, grass, brush and marsh), as a result of the land cover validation conducted by LLDA. Brush and grassland dominates the whole sub-basin with area of 8,438,384.14 square meters and 6,905,956.95 square meters, respectively, is seen in the northern to mid-portion of the sub-basin while marshland has the smallest area with area of 464,970.76 square meters found near the lake shore area. The urban area makes up 6% of the watershed

with area of 1,313,696.52 square meters which is found in the southern portion of the watershed (Figure 5-3 and Table 5-3).

Table 5-3 Land cover and Area

Land cover Area (sq.m.) Percentage

urban 1,313,696.52 6%

arable 2,445,685.11 11%

plantation 3,154,600.19 14%

grass 6,905,956.95 30%

brush 8,438,384.14 37%

marsh 464,970.76 2%

Total 22,723,293.67 100% Source: LLDA GIS

Source: LLDA GIS

Figure 5-3 Land Cover Map

Sub-basin Characterization and Properties Drainage Network The drainage properties of the Baras Sub-basin which is elongated in shape is presented and summarized in Table 5-4.

Table 5-4 Drainage Properties

Source: LLDA GIS

Parameters Values

Area (ha) 2270.629

Perimeter (m) 25649.063

Total number of streams 5

Total length of streams (m) 18257.546

Stream Density (stream/ha) 0.00220

Drainage Density (m/ha) 8.0407

Constance of Channel Maintenance (ha/m) 0.1244

Length of Overland Flow (m) 4.0203718

Source: LLDA GIS

Figure 5-4 Drainage Map

Sub sub-basin properties

Source: LLDA GIS

Figure 5-5 Sub-sub basin Map of Baras Sub-basin

Table 5-5 Baras Sub sub-basin properties

Sub-sub basin ID Area (Ha) Perimeter (m)

SSB-5A 1810.221 26351.760

SSB-5B 460.408 9795.825

Source: LLDA GIS

Water Quantity

Stream Flow The annual stream flow of the Baras sub-basin is presented in Figure 5-6. The maximum and minimum stream flow is in the year 2000 and 1997 amounting to 1.758615 m3 per second and 0.729353 m3 per second, respectively,

1990

1992

1994

1996

1998

2000

2002

2004

Baras

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Year

Stream Flow

(m3/sec)

Baras

Source: LLDA PDMED

Figure 5-6 Annual Stream flow (1990 – 2004)

Water Balance Based on the Sacramento Soil Moisture Accounting (SAC SMA) Hydrologic Model, the summary of the 15-year water balance of the Baras sub-basin is presented in Table 5-6. The average rainfall is 2,188, 31.12% of this turn as the actual evapotranspiration while more than half becomes direct runoff. Base flow of the total runoff accounts to 13.35% of rainfall and the rest is stored as groundwater and moisture in soil.

Table 5-6 Water Balance

YEAR Rainfall Actual Evapo-transpiration

Direct Runoff

Baseflow Change in

Storage 1990 2,389 690 1,384 403 (87)

1991 2,387 584 1,512 255 36

1992 2,117 571 1,210 217 119

1993 1,906 549 920 256 182

1994 2,098 744 1,067 310 (24)

1995 2,180 621 1,067 301 190

1996 1,918 764 877 290 (13)

1997 1,530 649 693 251 (62)

1998 2,107 576 1,042 189 301

1999 2,798 764 1,594 386 53

2000 2,880 789 1,594 365 131

YEAR Rainfall Actual Evapo-transpiration

Direct Runoff

Baseflow Change in

Storage 2001 2,185 803 1,023 342 16

2002 2,323 737 1,226 288 71

2003 1,923 673 961 260 28

2004 2,077 702 992 267 115

Average 2,188 681 1,144 292 70 Source: LLDA PDMED

Water Balance of Baras Watershed

31.14%

52.30%

13.35%3.22%

Actual Evapo-transpiration Direct Runoff Baseflow Change in Storage

Source: LLDA PDMED

Figure 5-7 Water Balance Percentage (1990 – 2004)