River siltation and reclamation
>> Sunday, October 26, 2014
PUNCHLINE
Ike Señeres
I was on board a radio program once and got a big kick when a supposedly qualified subject matter expert
told me live on the air that the streets were flooded because it rained. His
reasoning appeared to be acceptable based on ordinary logic, but he was
obviously not aware that even if it rains, the streets would not be flooded if
only there was a proper drainage system, and if only the rainwater that would
flow into the drainage system would have some outlets to go to, such as canals,
creeks, streams, rivers, lakes and bays. That is of course subject to the
condition that these outlets should be deep enough to take in the water flows,
and that is where the problem of siltation comes in.
Before going any further, I would like to make it clear that
a drainage system is not the same as a canal system. Drainage systems are those
that should collect the rainwater as it falls, and canal systems are those that
should collect the water from the drainage system as it flows. The problem is,
most localities do not seem to understand the difference between these two, and
that is why drainage systems are rarely found, and proper canal systems are not
found at all.
What I mean by proper is canal systems that are
interconnected to each other, not isolated canals that are found here and there
without going anywhere. I admit however that my definition is somewhat,
liberal, because strictly speaking, there might be no need for a canal system
if there is a proper drainage system.
Siltation is a problem because it builds up solid deposits
in the beds of creeks, streams, rivers, lakes and bays. As the siltation builds
up, these deposits would pile up to create bigger solid masses, sometimes
forming virtual islands in the middle and on its sides. Siltation is caused
either by the natural soil or sand movements, or the artificial movements of
soils and sands due to mining activities. Further complicating the problem of
siltation is the problem of garbage accumulation in the waterways that is now
happening not only in the cities but also in the countryside. Just like soils
and sands, garbage such as plastic bags and aluminium cans pile up and add to
the mounds of the virtual islands.
The flooding problem is not as simple as rain falling on the
ground, but it is as simple as subtraction and addition. Since siltation has
reduced the available space in the waterways, the answer to the problem is to
reduce the siltation in order to add available space for the rainwater coming
in. Removing the silt and the garbage deposits in the waterways is the only
available option, but then again these deposits have to go somewhere, and if
these would have nowhere to go, there would be another problem created. It
seems therefore that planning a land reclamation project nearby would be a
logical option, because it would provide a win-win solution. Looking at the
practical side, the value of the land created by reclamation would be more than
enough to pay for the cost of removing the silt and garbage deposits.
Solving the problem of flooding actually achieves the twin
objectives of disaster risk reduction (DRR) and climate change adaptation
(CCA). These two concerns are actually two sides of the same coin, and these
should be addressed simultaneously, preferably by the same government agency.
As it is now however, the DRR function is under the National Disaster Risk
Reduction and Management Council (NDRRMC), while the CCA function is under the
Climate Change Commission (CCC). Even if there could be some problems in
coordinating these two concerns at the national level, there are some
opportunities in coordinating these at the regional level, specifically at the
Regional Development Councils (RDCs).
Common sense would tell us that our regions are actually
broader ecosystems that should be planned together and managed as one, at least
from an environment perspective. I say broader, because the ecosystems of the
provinces are too small to be managed as one, not to mention that these smaller
ecosystems could not, and should not be managed apart from the broader
ecosystems that they are part of. One advantage of planning and managing
environmental concerns at the RDC level is the attendance of national agencies
that are also involved in the environment, such as the Department of
Environment and Natural Resources (DENR), the Department of Science and
Technology (DOST) and the Department of Public Works and Highways (DPWH).
To give credit where credit is due, the DPWH has already
removed the silt in the bigger waterways of some regions, and the only
remaining challenge now is how the provinces and municipalities in these
regions could maintain the cleaner status of these waterways. This is indeed a
challenge, because without clearer environment programs and without stricter
law enforcement, it is difficult to see how the new build-up of silt and
garbage deposits could be prevented. Thanks to new technologies, it is now
possible to monitor and track the status of clean-up efforts, including those
that are done by the local government units (LGUs) in the smaller waterways. I
hope that this data could be eventually uploaded online, for everyone concerned
to see.
As required by national laws, all LGUs are supposed to
produce their own Comprehensive Land Use Plans (CLUPs) that are supposed to be
renewed every ten years. As I understand it, most of these CLUPs are static in
nature, and may have not used the newer technologies for Geographic Information
Systems (GIS) and Global Positioning Systems (GPS). If only GIS and GPS would
be used for CLUPs, it would not only become interactive, it would also become
dynamic. Considering the pervasiveness of cell phones in this country, it would
also be good if the CLUPs would have some form of mobile integration, so that
more users could access the data from more device options.
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