Our Wetlands: Can we really live without them?

Our Wetlands: Can we really live without them?

By Imam Soeseno

JAKARTA (JP): Last March, for the second time, the region in
the vicinity of Professor Sedyatmo Highway was flooded due to the
incidence of a rather high rainfall.

When was the first flood occurrence? It was only February
1993.

Some sources say never before they experienced such floods.
This first flood happened not long after wetlands were destroyed
to make way for construction.

Many think that this "conversion" of wetlands is the cause for
the new string of floods. The fact is that 30 hectares of
wetlands have been filled up for the purpose of erecting
factories. The reclamation was then continued with a much-debated
development of a luxurious Pantai Indah Kapuk residential and
commercial site. This site has consumed 100 hectares of wetlands
and will take some 832 hectares more.

The occurrences of floods is a failure of the hydrological
system caused by wetlands reclamation.

Therefore, we must now reevaluate the role of the 40 million
hectares of wetlands spread over in our four main islands. We
must also decide whether these regions can be classified as
unprofitable areas that are economically and ecologically
disposable.

Ecological functions

The word 'wetlands', an invention of the age of ecology, is a
relative newcomer to the language and requires some sort of
explanation. It used to be that most people were content to speak
of marshes and swamps without bothering the difference between
the two.

A marsh is a wet place with herbaceous vegetation, while a
swamp is a wet place dominated by shrubs and trees. There are so
many different kinds of each, namely bogs, sloughs, floodplains,
estuarine marshes, to cite just a few. The cover-all term for all
of these terms is 'wetlands'.

According to the data provided by the Directorate of Swamps of
the Ministry of Public Works, we have almost 40 million hectares
of wetlands spread over on four main islands of Sumatra, Java,
Kalimantan, and Irian Jaya.

All of them are open for reclamation, mainly for agricultural
purposes, under the coordination of the directorate. The
reclamation, according to regulations, has to be based on the
concept of sustainable development.

In its soul, though, the regulations encourage reclamation in
the hopes that those 'wastelands' might soon bear the fruits of
sustained agriculture.

Nobody would argue that wetlands is a form of rich and complex
ecosystems. We all realize wetlands are producers of life, some
being equal in output to a same-size chunk of tropical rain
forest. They are places of plenty; it would be easy to find
numerous species of birds, fish, and microbes.

A bakau forest or mangrove has at least 60 plant species and
more than 2000 species of aquatic and terrestrial fauna.
Certainly, you have also an understanding of the ecological term
"biological diversity", then wetlands could claim to be on the
most top list to be preserved.

Richness

With their richness of plants, wetlands lock up large amounts
of carbon -- mostly in the form of peat -- thereby preventing it
from entering the atmosphere as carbon dioxide. This compound is
the principal culprit in global warming.

So who cares? Certainly not the utilitarian who eats no fish,
eschews bird watching, scoffs at the concept of biological
diversity and regards global warming as an elitist scam. Still,
do swamps have any value for those people too?

I will let the biologists explain how we have lost invaluable
fishery potential due to our indifference in loosing our coastal
wetlands or how, in 1984, the outbreak of malaria took place in a
village near Cilacap (southern Java) due to the lost of the
region's mangroves. In this matter I am only a laity and as an
hydrologist I would pursue the discussion toward the problems of
water quality and availability.

People need water at the right quality and also quantity. In
the context of discussing wetlands, the problem is, people need
protection from too much water in the wrong places at the wrong
times, that is, floods. How do wetlands have something to do with
floods?

Wetlands serve the environment as the so-called retarding
basin. On the times of high tides, streams and rivers have their
flows slowed due to lower hydraulic head gradient. The coastal
wetlands take up all excess water. Inland marshes sponge up
runoff, thus reducing flood crests downstream.

Flourishing in the middle of river meanders, floodplain forest
serve as reservoirs during times of high water. Instead of
letting the water rush downstream, flood water pools behind
natural levees and in sloughs and oxbows, and is then slowly
released. Not only the swamp trees slow the river's water speed,
the thick woody vegetation also traps sediment.

As natural purifiers, small swamps with tall trees at the
center act to eliminate wastes carried in water. Fed domestic
sewage and agrochemicals, the tree roots remove most of the
harmful nitrates and phosphates, binding them up in mud and tree
roots. However, it must be acknowledged that this function may
became overloaded as our water is more and more polluted.

Sacrifice

Jakarta used to be rich not only in coastal wetlands but also
in inland wetlands as well, which were preserved and guarded
fanatically by our ancestors. Now we may sacrifice all of them in
the name of development.

In their place has sprung expensive mansions. Only luxurious
buildings could afford the expensive costs of wetlands
reclamations.

But at the end, the loss of retarding basin functions has
caused many places like Bintaro, Pondok Aren, and Jurang Mangu to
experience floods for the first time.

Recently, there has been a movement to build artificial
retarding basins in lieu of their natural counterparts in efforts
to alleviate the flood problems. It is such an irony that we, all
of the tax payers who are the innocent party in such cases, have
to pay for their construction. If those wetlands still existed
they would provide that service free, for all of us.

It is interesting to discuss the case of floods happening on
the nearby areas of Pantai Indah Kapuk (PIK) residential estate.
This luxurious site employs the well-known "polder system"
imported from the lower-than-sea-level country, the Netherlands.

In brief, the housing estate is lower than the average high
tides, therefore a network of dams becomes necessary. The former
wetlands functioned as a retention basin, but the PIK now has
built a replacement for this, the so-called "longstorage"
completed with pumps.

With this artificial reservoir, the water excess from PIK site
could be temporarily collected in the storage system and released
to the Cengkareng Drain.

Failure

The occurrence of flooding might possibly have been caused by
PIK's failure to keep the functions of wetlands it has previously
reclaimed. By building a network of dams for the polder, PIK has
disconnected the reclaimed wetlands from the natural reservoir
system of the region. This way, PIK has reduced the water
retention capacity of that natural reservoir as much as the area
of wetlands it acquired.

It is completely unacceptable to build its so-called
longstorage system while disconnecting the system from the
surrounding wetlands! It used to be that the wetlands in the
region, some in the form of brackish-water ponds, were
interconnected by networks of small channels.

The increase of the water level in any place could quickly and
easily be distributed over the whole region. Not any more with
the development of PIK.

It is absolutely true that we should not arbitrarily place the
value of wetlands above everything else. However, comprehensive
studies on the role of certain site toward its broader
environment could help preventing failures in the hydrological
system. As a hydrologist I am sure the failure to asses these
problems have increased the occurrences of floods in the area.

The writer is a hydrologist and an environmental impact
assessor.