Disseminating Garble Flood Information!!!

Over the TV network, we hear reporters interviewing hydrologists from PAGASA explaining to the public the water levels of the dams. We hear about spilling level, alert level, critical levels, and so on. Who cares about those categories if they can't be understood.
Even reporters, follow these cues from PAGASA, NIA, NPC, etc.  by citing this so and so meters of water level of dam... or river stage in Marikina River is now 18 meters. There  is something wrong with the reporting because it is not vividly interpreted by a layman. If the  goal is to be mobilized by every pronouncement from the reporter, the water level in meters is nonsense. It takes time to understand what the reporter means. Even as technical person, I have to think what those figures mean.

FLOOD COUNTERMEASURES UNDER TIGHT BUDGET

In the Philippines, the design parameters in the preparation of master plans and feasibility studies, implementation, operation and maintenance of flood control projects are greatly influenced by the economy of the country. For Metro Manila, 30 year return period for river improvement, and mostly less than or equal to 10 year for drainage works are implemented on a phase to phase basis. Budget comes in trickles resulting to delays in the implementation. Optimal operations of flood control appurtenances are not attained. The equipment; which necessitate immediate replacement or rehabilitation, outlast the efficiency level over years of use.

Due to growing population, topographical changes, and the impact of climate change, structural measures limited to design flood level cannot cope under extreme condition, and the master plan and feasibility studies are becoming less and less feasible. Land subsidence due to water demand, land use changes due to development in the upstream and downstream reaches, encroachment of waterways both by influential and marginal groups, are considerations to update and revise the master plans and feasibility studies. However, the financial capability of the government and the duration to implement the priority projects are still uncertain.

As vulnerability of the people in the flood prone areas increases, viable alternatives affordable through local resources should be pursued. Some innovative measures require short term implementation that can increase the security of the affected populace. Flood forecasting and warning system are becoming more popular and acceptable as private entities begun to get involved and cooperate. However, some significant aspects, such as those which relate to political and social factors , are hard to change in a short term. Urgent works should be sourced from available local funds which are low cost in nature to supplement the non-structural countermeasures. Though conceptual, these may include heightening of the house in highly susceptible areas, viaduct for mobility and passage during flood time, maintenance of waterways engaging community participation, accessible and safe evacuation centers, etc.

Philippine Strategies to Mitigate Flood Disasters

For the past decades, the Philippines has been experiencing climate variability with extreme rainfall. Some areas, especially the southern part, are now frequented by typhoons and heavy rains where before such phenomena were rarely experienced resulting to disastrous run-off to a surprised populace. In reaction to series of disasters, the government has been formulating and implementing measures to alleviate the negative impact of these calamities. Among these are reviewing and enforcement of policies dealing with river easement and  flood control, establishment of nationwide early warning system through improvised hydrological sonar gauges linked through SMS and internet, acquisition of LiDar digital elevation maps for flood modeling and flood forecasting, and production of hazard maps as guides for land use planning,  and formulation and revision of master plans and feasibility studies for flood management in prioritized river basins. At this stage in a changing environment, accuracy and reliability of each measure is still rudimentary.

While the country is developing flood disaster management, there are still many issues to resolve. At present flood plain management is governed by the current policy on river easement.  It is enforced hardly as there are many encroachments legally and illegally in the waterways. At the same time, river boundaries are not clearly established even in urbanized areas and especially where river shifting is experienced. Another issue is the watershed where settlers are uncontrollably falling down trees and bushes for agricultural purpose, for firewood and as means of livelihood.

It is indeed a big challenge to clear the high risk areas in flood plain and watershed areas where more often available budget for relocation and political interest are big stumbling blocks. These could be one of the foreseeable reasons for poor implementation of land use and watershed management.

On modeling, flood hazard mapping, flood forecasting, warning, and planning, the country has spatially sparse hydrological data plus the changing norms due to climate change. Also, data sharing even among government agencies is not cohesive. Dissemination of warning information becomes confusing also, because many players are now involved in processing and in media release. It is also found out that there are discrepancies between the actual and the acquired data. As there are few local experts on modeling, calibration to get more efficient results may take some time.

Lastly, due to limitation of budget, flood management implementation in different river basins is prioritized according to risk and necessity. At the rate of occurrence of disasters on nationwide scale, priority ranking will be revised soon.

Each key issue is examined to recommend improvement of measures adaptable and fitted to the communities at risk.

Please Free PAGASA Hydro-Meteorological Data !!!

Why is PAGASA selling their data? Are the staff of PAGASA not getting their worth for their work?

Who suffer?

1. Student researchers who have no additional money to shelve from their allowance and the parents who have to allot from their meager salary.
2. Researchers from other government agencies. - Honestly getting data from climatological division of PAGASA is cumbersome. Writing letter request to be signed by top honchos which takes time, then approval from PAGASA to get free data?
3. The people who should benefit from the researchers and studies because the deprived data did not reach  the researchers.

This move by PAGASA discourages researchers. Consider the travel time of going to PAGASA if you were from the province and the bureaucracy the request for data will pass through before it can reach the concerned person.

We hope there are other agencies who can give free data. Well,  time  will come when the GSMAP or the TRMM will be released with high accuracy and  frequency and could be downloaded free of charge.  Then we can say  to PAGASA Climatological Division, "Good Bye!!! You can have all your data."

 

Structures for Display!!!

Napindan Hydraulic Control Structures is one of the projects by the Philippine Government worth visiting as far as its function is concern. It was completed in 1983 under ADB funds designed by Japanese Consultant for the purpose of salinity control of Laguna Lake. It has four flood gates and navigatonal lock to regulate the flow of salt water from Pasig-Marikina River to Laguna Lake via Napindan Channel and to allow small boats and barges to enter in and out Laguna Lake, respectively. Secondly, the Napindan Channel drains  flood waters from Laguna Lake resulting from discharges diverted from Marikina River through Mangahan Floodway and inflows from twenty one tributaries around the lake.

In 2002, through the wish of then MMDA Chariman Bayani Fernando, it was transferred from DPWH to MMDA. From 2002 to 2011, it was poorly  maintained because the funds were not included in the package.  Since then, the floodgates and the navigational lock were always open through out the years as the gates corroded for lack of maintenance and lubricants.

So what happens now to regulating  salt water intrusion to Laguna lake.  Logically, free flow from Pasig-Marikina River to Laguna Lake and vice versa due to diurnal tide fluctuations and seasonal highs and lows of lake level proved  the structures to be futile. With and without the structures,  polluted salt water from Manila Bay comes in and out the lake. Environmentalists  suggest to close the gate whenever the water level of Pasig-Marikina River is higher than the lake stage or during  high tide to prevent pollution to enter the lake. However, it is contended  by  fishefolks because they claim that they need salt water to  propagate their fingerlings during dry season in the lake.

Normal rule is that the floodgates are opened during flood times whenever high discharges  from Marikina River occur to allow inflow to Laguna Lake to prevent downstream overflow, that is Manila area. During high lake stage when most of the coastal towns are flooded, the  gates must remain open to drain the high lake stage. On occasions that the lake stage is higher than the Pasig River, the floodgates must be closed, which seldom occur.  At the moment  there is lack of river stage data in relation to lake stage to established its relationship..

The main purpose of the Napindan Hydraulic Control Structures is for salinity control and secondarily for flood control. With the floodgates open most of the time, ostensibly the project is functionally worthless.