CIRCULO VERDE

RIVER FLOW AND SILTATION

RIVER FLOW AND SILTATION

Denuded Marikina Watershed In the absence of enough trees, soil is easily eroded in downstream areas.

Eroded soil, garbage and mass from upstream become silt (burak) and causes obstruction of the river flow. (Siltation)

RIVER FLOW AND SILTATION

Siltation causes the river to become shallow, thereby reducing its carrying capacity.

Left: Photo showing a man walking across a shallow Marikina River.

RIVER FLOW AND SILTATION

A shallow river has less carrying capacity and therefore does not allow water to flow easily. This is siltation.

Siltation then causes water to spill over to unprotected property, and at the same time, restricts water passage.

MMDA Dredging Works In Circulo Verde in 2011

MARIKINA RIVER SHOWING MANGGAHAN FLOODGATE

Siltation happens at various points in the

river, even beyond the Manggahan Floodgate.

MANGGAHAN FLOODGATE

Enlarged view of heavily silted areas near the Manggahan floodgate.

LOT PROFILE

Aerial photo showing Circulo Verde perimeter line. Anything beyond the black line / white flags is silt.

Aerial photo showing our boundary limits

PTS. 1 TO 6

PT. 14

PT.15

PTS. 6 TO 14

KEYPLAN

Perimeter line represented

by white flag.

Mass of silt that is not part of

the property.

RIVER FLOW AND SILTATION

Contributing to siltation is human factors such as household waste from informal settlers who live along the river.

Left: Photo of informal settlers along the Marikina River.

Source (Aggregator site): 7 Ondoy cities unite to protect watershed. http://article.wn.com/view/2011/03/19/7_Ondoy_cities_unite_to_protect_marikina_watershed/

C I R C U L O V E R D E L O TFebruary 2007 Satellite Map

Silt along the river banks in the absence of a retaining wall.

N

C I R C U L O V E R D E L O TFebruary 2010 Satellite Map

Absence of silt after part of the wall has been put up.

Ortigas is investing a total of P300-million for the development of the perimeter retaining wall and the dredging to follow.

Circulo Verde River Protection Wall

• 8 meters high• 1.5 kilometers long

Left: Photo of the Marikina River that is protected from erosion thanks to the river wall.

Circulo Verde Aerial Site Photo

Aerial view of the Circulo Verde site with the river wall in place. Accumulated silt is no longer visible.

And the development continues to other parts of the site…

More silt to be removed and more areas to be covered by

the wall.

Circulo Verde Aerial Site Photo

More areas to be covered by the wall. After which, dredging will follow.

• Ortigas has acquired all the permits for the development of Circulo Verde and the perimeter wall.

• It has master-planned Circulo Verde with engineering, hydraulics, and architectural experts to work with and around nature.

• It has invested P300-million to put up a 1.5 kilometer wall to keep soil from eroding along the banks and pave the way for effective dredging.

As a responsible developer with over 81 years of experience in real estate development, Ortigas & Co. has master-planned Circulo Verde to work with and around nature and ensure the safety of its residents and neighboring

communities.

CIRCULO VERDE HISTORICAL MAP: LAND CONFIGURATION

There is a constant change in land configuration due to flowing water as seen in the maps from 1904 until 2010. Over time, water has eaten away

parts of the Circulo Verde property.

Circulo Verde Property Line and Proposed Riverwall

Original OCLP Property Line since 1904

Alignment of Constructed Riverwall (OCLP)- Length +/- 172 M

Proposed Alignment of Riverwallfor Construction (OCLP) – Length +/- 832 M

The construction of the river wall will stop further erosion, widen the silted river, and increase the river’s carrying capacity.

The construction of the wall was validated by the studies conducted by DCCD Engineering and Dr. Guillermo Tabios of the National Hydraulic Research Center of the University of the Philippines.

• Ortigas has acquired all the permits for the development of Circulo Verde and the perimeter wall.

• It has master-planned Circulo Verde with engineering, hydraulics, and architectural experts to work with and around nature.

• It has invested P300-million to put up a 1.5 kilometer wall to keep soil from eroding along the banks and pave the way for effective dredging.

As a responsible developer with over 81 years of experience in real estate development, Ortigas & Co. has master-planned Circulo Verde to work with and around nature and ensure the safety of its residents and neighboring

communities.

Thank You