Rizal Philippines | September 23, 2014
The area near the SM Marikina is inundated because the floodway which is just 30 meters wide and 4 meters deep vis (100 meters and 10 meters) is choked and thus Pasig river, which is it was designed to empty into Laguna Lake, is flooded
Floods at Ortigas Avenue ( can we relate this to the abuse of Pasig River and Manggahan floodway?)
What caused the flooding? A flurry of interviews and TV shows and articles are coming out to analyze again the cause of the flood:
Again let us enumerate:
1. Force majeure - the 269 mm of rainfall for the 24 hour period is the equivalent of 1/2 month of rainfall.;
2. Global warming - the warm Pacific Ocean and atmosphere loads typhoons with more energy and moisture that fall as rain. This is a very convenient excuse
3. Clogged drainage - plastics, sand, silt, trash clog the drainage
Garbage and encroachment on esteros; we cant fight nor convince developers to demolish their encroachment
4. Flood control projects, pumps that do not work (Espana has had several flood control projects and yet it floods at when the dogs piss.)
Squatters must go? Or they and us suffer floods endlessly?
Squatters at floodway banks (west bank) We have no will to resist their votes?
Would the flooding be the same if the banks of floodway were cleared of squatters?
From GMA news - encroachment of Manggahan floodway blamed for Pasig river swelling. It has become narrower and shallower - thanks to.....
5. Settlers on esteros and river banks (accretion). Pasig river then looked very wide. Now it seems that it is only 15 meters wide. Manggahan floodway is heavily silted. Squatters dump their shit and garbage at Manggahan floodway.
From here we can judge that the Manggahan floodway overflow, flooded Ortigas Ave after the Manggahan bridge. Manggahan floodway should be dredged and declogged.
From coconuter (mambubuko?)
6. Subdivision developers narrow creek to maximize saleable areas, and sometimes kill them entirely. Hence the flood waters coming down from the Antipolo Mts. flood Ortigas and Marcos HIgh way.
The red line represents the canal that should have been built.
From Nuideashare
Alternative spillways
From invision free
Proposed second East Spillway at Laguna - Siniloan area.
6. As per per fmr Sec of DPWH, now governor of Zambales, the incomplete Manggahan floodway, Laguna lake project is incomplete. There should have been a canal form Laguna Lake to Manila bay. This was not completed because of very expensive right of way.
Because of this, the floodwaters caught at Laguna Lake takes at least 3 months to recede. The 12 km or so Pasig river which is the outfall of Laguna Lake via the Napindan channel has very narrow window of function because of the tides.
Right now we are blaming everybody. We have no one to blame except ourselves. Let us move and correct.
We all know the problems and causes and yet nothing is being done resolutely and continuously to address the problem; all fits and starts, and when there is no flood again we stop and lose focus and attention
Can you still see the river?
Clogged Tunasan causes flooding in Muntinglupa
Can we solve the flooding and beautify our rivers and esteros too
Master plan for flood control of Laguna lakeshore
The following are the optimum solutions in solving the flooding situation in the Laguna lakeshore area:
1. Putting up a road dike around the lake with pumping stations
2. Lakeshore land raising with road and future developments
3. Construction of a spillway that will cut through the heavily built-up Parañaque City and another one that will go through to the Pacific Ocean
4. Dredging works
5. River improvements for the selected inflow rivers of the lake developments
Full detail:
DPWH report: Flood management master plan for Metro Manila and surrounding areas
Published: June 19, 2013. Latest update: June 19, 2013.
http://www.gov.ph/2013/06/19/dpwh-report-f...rounding-areas/
*** Based on the info, I believe the 1st phase covering the priority list is okay. I humbly suggest speeding up the Marikina Dam (wawa dam?) since this will help hold water coming from the Marikina, Antipolo, Montalban, San Mateo areas.
The reforestation of the watershed is necessary and the relocation of squatters who have encroached the area must be done too.
The clearing of squatters, garbage and illegal structures in the network of canals in Metro Manila and the vital rivers like the San Juan river, Paranaque River and the connecting water channels must be done, as well as the setting up or rehab of the pumping stations. The JICA-funded pumping stations in Navotas miraculously saved Navotas from the Ondoy floods.
Dikes are necessary too. After this, we need to consider how we can increase the discharge rate of the "Pasig River-Laguna bay" network to cope up with the sustained rainfall. This means how we can drain faster the waters from Laguna Bay, which could be another spillway leading to Manila bay or the Pacific.
Also, the gradual relocation of settlers that will be affected by the Paranaque Spillway project must be started. Perhaps, the portion of the project near the mouth of Manila Bay maybe started already to expedite the project completion.
If you will review this proposal for the spillway, 80% of the length is not yet covered by any home or building.
The reason now is not because of "being heavily built already" but the lack of political will. Worse, the selfish interest of some politicians.
The gov't must also prevent further development of the areas that will be covered by the proposed project in order to not complicate the problem on "relocation & right-of-way acquisition" further.
