Floods:Jakarta Biopores

[jpatokal]

While Bangkok worries about the possibility of floods caused by high sea tides, in Jakarta it actually happening is just another normal day. Jakarta Post (http://www.thejakartapost.com/detailgeneral.asp?fileid=20071126225903&irec=1):

North Jakarta floods, city traffic at standstill

Flights were delayed, thousands of passengers were left stranded and the toll road to and from the airport was impassable as floodwaters from the sea off North Jakarta inundated parts of the city Monday.

An ignored warning of a cyclical high tide and a neglected sea barrier, which broke over a week ago, contributed to the congestion and confusion at the Soekarno-Hatta international airport.

Floodwaters submerged Pluit and Penjaringan subdistricts, disrupting traffic and forcing residents to flee their homes in North Jakarta's coastal areas.

Traffic was paralyzed with congestion stretching from the Soekarno-Hatta tollgate to Slipi in Central Jakarta at around 8 p.m.

That last sentence, incidentally, means that there was 30 kilometers of traffic jam. I flew in yesterday morning, but evidently managed to escape about an hour before things got hairy... :eek:

[Yappofloyd]

I was due to fly to Singapore at 3pm today but there had been heavy rain since 11pm last night and many roads were flooded. I couldn't even get out of my large hotel as the whole road was flooded. Later, I spotted some people unloading a rubber dingy from truck. By late morning, I was advised the airport was a mess and that parts of the toll road road to the airport resembled a canal.

Have to feel sorry for all the poor living alongside the rivers and canals in the slums.

Even the Indonesian President had to reportedly abandon his car!

Indonesia closes Jakarta airport due to heavy rain The Associated Press
Friday, February 1, 2008

JAKARTA, Indonesia: Indonesia was forced to temporarily close its main international airport Friday due to poor visibility following torrential rains, officials said. Almost 150 planes were delayed or diverted and thousands of passengers stranded.

Roads across much of the sprawling capital were submerged in knee-deep water, bringing traffic to a near standstill and forcing many people to abandon their vehicles — including the country's president. The main highway leading to Sukarno-Hatta International Airport also was cut off for much of the day.

The airport was reopened after five hours. "The runways weren't flooded," said Hariyanto, a spokesman for the airport. "But visibility fell to less than 300 meters (330 yards) — compared to the minimum standard of 500 meters (550 yards)."

Seasonal downpours cause dozens of landslides and flash floods each year in Indonesia, where millions of people live in mountainous areas or near fertile plains, and the bustling metropolis of 12 million is rarely immune. Last year, more than 40 people were killed in Jakarta after days of incessant rains caused rivers to burst their banks. Critics said rampant overdevelopment and clogged sewage canals were partly to blame.

Hariyanto said 92 flights were delayed and 55 diverted to other airports Friday, including several international flights. At least 8,000 passengers were stranded after hours of pounding rain inundated nearby highways, he said. Officials deployed dozens of buses to transport some to Jakarta above the black, muddy water.

President Susilo Bambang Yudhoyono was forced to abandon his bulletproof Mercedes-Benz Sedan two kilometers (1.24 miles) from his palace over fears it would get stuck in the flood. He jumped into one of his secret service's SUVs, leaving his motorcade behind.

[Yappofloyd]

Jakarta stops in face of floods City News - February 02, 2008 The Jakarta Post
Appointments were canceled, passengers were left stranded and residents were forced to leave their homes. Jakarta was chaotic on Friday. Hours of heavy rains that started Thursday night saw many parts of the city come to a standstill by Friday afternoon.

Water inundated main thoroughfares, including the Sedyatmo toll road to the Soekarno-Hatta International Airport. "At the toll to the airport, motorists were trapped in traffic since 2:00 p.m.," Traffic Management Center (TMC) officer First Brig. Yoka Mulyadi told The Jakarta Post Friday night. "Many were reported to have fainted. We received many calls for help; the trapped motorists asked us to send drinking water and food," Yoka said.

He said there were more than 40 locations inundated by waters up to one meter high. Rainwater flooded many of the capital's municipalities, with 37 of 267 subdistricts inundated more than 40 centimeters high. On Jl. Gatot Subroto, Yoka said, people were trapped for more than three hours in traffic jams, from 4:00 p.m. to 7:30 p.m.

In some areas, people were seen walking on foot or sharing a ride on open trucks after failing to get public transportation. Sukma, a motorist, said Friday he had to push his motorcycle from Jl. Gunung Sahari to reach his office located on Jl. Kebon Kacang in Central Jakarta. "I have pushed my motorcycle for about an hour and now the machine is badly broken," Sukma said.

Floodwaters caused public transportation across the city to stop operations. Three Transjakarta lines were stopped by noon, leaving hundreds stranded. Stoppage information was not given to those waiting at bus stops. Yudi said he and his mother waited for a Transjakarta bus traveling from Harmoni to Pulogadung, to no avail. "The flood is so awful everywhere. We don't know how we can reach home in Pulogadung," he said.

PT KA's head of public relations for the Jakarta area Akhmad Sujadi said the water submerged railways stretching from Rawa Buaya to Kalideres, causing the company to cancel the Tangerang-Jakarta's train route. "We also stopped carrying passengers between Serpong and Tanah Abang," he said. Five trees were reported to have fallen across main thoroughfares, adding to traffic congestion.

Floodwaters also submerged residential areas. In West Jakarta, around 1,000 Pegadungan residents were evacuated to a mosque compound, while 150 Semanan residents moved to a shelter nearby, said municipality spokesperson Rachmat Mulyadi. "The water levels in the area is about 1.5 meter," he said.

West Jakarta task force center recorded 3,000 residents had been evacuated from their homes. Adi, an officer at the North Jakarta task force center, said there were around 300 residents in five shelters. He said in one of the camps, displaced people included women and children, but that many men had preferred to stand guard at their homes.

Airport closed, thousands of travelers stranded City News - February 02, 2008The Jakarta Post
Bad weather and heavy rain saw the temporary closure of Soekarno-Hatta International Airport on Friday and air traffic across several cites grounded or diverted. The international airport was closed from 10 a.m. to 3 p.m., with 58 flights re-routed and 177 delayed. The 58 flights were diverted to five other airports including Halim Perdanakusuma in East Jakarta, Sultan Mahmud Badaruddin II in Palembang, Ahmad Yani in Semarang, Juanda in Surabaya and Changi in Singapore.

"The runways were closed because of cloud hanging over the (Soekarno-Hatta) airport area and visibility was less than 300 meters, while it should be more than 500 meters," the airport's executive general manager Haryanto said. He said the southern part of the airport's runway was submerged in waters up to 50 centimeters high, making it impossible to allow airplanes to land.

Haryanto said estimates of losses caused by the long delays had yet to be made. Thousands of passengers stranded at airports said they experienced delays and diversions as well as poor service from airport management. At Halim Perdanakusuma, passengers said information from the ground units was not well managed.
Note: Edited

All wet, again Opinion and Editorial - February 02, 2008 Jakarta Post
Jakarta is flooded, again. Just one day of incessant rain, from Thursday night through Friday morning, was enough to paralyze the capital with floods. Although flooding is a relatively regular occurrence in the city, Friday's flooding seemed to have caught many people off guard. Residents were unprepared for the floods, as were the police and city administration. No one, no institution, not even the Meteorology and Geophysics Agency (BMG), warned residents to be ready for the floods.

True, the BMG did forecast heavy rain Friday in Greater Jakarta, but it never mentioned the possibility of flooding. When the capital did find itself underwater Friday morning, the story dominated radio and television stations. By that point, of course, it was too late to do anything but watch the disaster unfold. The level of unpreparedness among residents, officials and police left the city in chaos, with massive traffic jams everywhere.

Commuters spent hours trapped in their cars or on busses, with traffic at a complete standstill in many areas. The flooding this time also disrupted flights at Soekarno-Hatta International Airport, the country's main airport. The main access road to the airport was flooded, and the airport's two runways were closed for about four hours because of heavy rain, strong winds and lightning. The flood simply brought the city's economy grinding to a near complete halt.

A calculation of the losses from Friday could brings us into the trillions of rupiah. These losses are from lost business opportunities, the damage caused by the floods and the lost productivity, from people stuck in traffic and those who simply stayed home to avoid the chaos. That is just the cost from one day of flooding. It will naturally shoot up should the flooding extend into the next day and the next.

Considering the massive costs, it is time the city administration and the City Council draw up a comprehensive plan to prevent flooding and improve flood mitigation efforts. We have long heard about a number of big flood-control projects, including the long-awaited East Flood Canal, which has been progressing at a snail's pace, if that fast. Funding problems, especially the unclear division of funding between the central government and city administration, have been holding up the project for years.

Aside from the major flood-control projects, the city administration should immediately launch projects to improve the city's drainage system -- if there is any -- or build a completely new and proper one. Experience shows that even a small amount of rain in Jakarta can cause flooding. This is often because of the garbage-clogged drainage system. It is simply a bad habit for many people to toss their garbage into sewers, ditches, gutters and rivers near their houses.

The cost of clearing the city's drainage system of all this garbage is huge. Therefore, a concerted campaign should be pursued to educate people not to clog the sewers near their homes with garbage. If necessary, punish those who fail to dispose of their trash properly. But this entails the city administration living up to its responsibility. It has to provide the infrastructures, including garbage cans, garbage dumps and trucks to collect the trash.

Clearing the banks of the city's rivers of squatters is also necessary. The city's administration seems to understand this, and has taken some steps to relocate those living illegally along river banks. But these measures will take time to complete, and we cannot wait any longer for the next major flood. In a situation like we faced Friday, with flooding everywhere, response measures like the evacuation of affected residents and the distribution of aid are all flood victims need.

Learning from past floods, we urge the city administration and all related authorities to improve their readiness to assist flood victims. We also commend the participation of residents, especially the many volunteers from private companies and organizations, in helping flood victims. Our people are often united in despair. The help is there, but what is needed is proper warnings to assemble and deploy. When floods happen without proper warning, as on Friday, we are all helpless.

[Yappofloyd]

It took me 3 hours (normally a 30-45 min trip) to get to the airport on Saturday afternoon as the toll-road to the airport was still closed being under 50cms of water. I ended up missing my flight to Singapore but was on another 5 hrs later. Traffic to and from the airport using backroads was at a snailspace and at one point only 5kms from the airport my taxi took an hour to travel 2km!

Many other passengers also missed their flights. In retrospect, I realised that I should have taken the Damari Airport Bus from Gambir station as reportedly buses were still allowed through the flooded area of the toll road.

Later, whilst I was checking in I bumped into a couple of Malaysian guys who missed their flight to KL. They described their airport journey; involving two different taxis that became each became stuck at diff. points, thus wading through knee deep water with their luggage on their heads, then having to jump on to the back of a medium size builders truck and then walking a km or so until they found some motorbike drivers who took them the final few kms! Luckily, they were able to get on a later flight.

Hopefully, the planned airport rail link will built on a viaduct above future potential flood levels.....

Flood waters down, but city still on alert City News - February 03, 2008 The Jakarta Post
Despite clear weather and receding waters on Saturday, the Meteorological and Geophysics Agency says Jakarta resident should brace for more floods before the end of the month.

The agency has predicted cloudy skies and heavy, prolonged rainfall in the coming weeks. "The rains we had recently were caused by a weather pattern called the Madden-Julian oscillation, which increases the possibility of massive rains that may last from three up to four days," the agency's head of research and development, Mezak Arnold Ratag, told The Jakarta Post on Saturday. The pattern, he said, usually affects weather in a region from 30 to 40 days.

Mezak said that flooding could also occur due to rainfall in upstream areas such as Bogor and Depok. "In such cases, Jakarta would be heavily flooded again because the excess water would flow into the city," he said. Mezak said the city would have been in a better situation this month if it had prepared its drainage system earlier. The Jakarta Police's Traffic Management Center said that the number of flooded areas had dropped from 140 to 27 by Saturday.

Many people have returned to the houses they left to the waters on Friday. Residents of Kampung Pulo in East Jakarta, which was inundated up to 1.5 meters deep in parts on Friday, have begun cleaning up their homes. Mohammad Harris, a Kampung Pulo community unit chief, said that they were still ready for more floods. "We are still on alert as it is the time of the year where the big floods come," he said.

Some areas of the city are still underwater. Rawa Buaya of West Jakarta, suffered heavy flooding after the rain had stopped because the water level in the Angke River had risen and burst its banks. A resident, Sriyono, said he had not been prepared for the floods. "The water starts to rise quickly on Saturday morning," he said, adding that it was high as an adult's stomach on Friday.

The Sedyatmo toll road, the main link between the city and the international airport, was still flooded 50 cm deep on Saturday. A lack of public transportation to the city meant many arrivals were left stranded at the airport, while passengers on their way there struggled to find alternative roads. "We won't allow sedans or any low-level vehicles to cross the toll road," said Adj.Sr. Comr. Mujiana was quoted by Antara news agency as saying. Thousands of people were left stranded by floods that affected 14 percent of the city's 267 subdistricts on Friday.

Water inundated main thoroughfares, railways and the runway of Soekarno-Hatta International Airport. More than 3,000 residents were forced to leave their homes. The Health Ministry's Crisis Management Center recorded at least three people dead on Friday due to drowning, while the Greater Jakarta division of state-owned railway operator PT Kereta Api recorded Rp 550 million (US$57,894) of losses due to travel delays and railway deterioration.(anw/ewd)

[Yappofloyd]

Reduce urbanization Opinion and Editorial - February 09, 2008 Jakarta Post Deden Rukmana, Savannah, GA

In February 2007, the worst flooding in Jakarta's history inundated about 70 percent of the city, killed at least 57 people and sent about 450,000 fleeing their homes. Almost exactly a year later, floods hit Jakarta again. This clearly indicates that flooding is an annual event in Jakarta. Fortunately, the extent of this year's flooding was not as great as in 2007.

Hours of heavy rain in Jakarta caused most of the main roads in the capital to be submerged in knee-deep water, bringing traffic to a near standstill. Thirty-seven of 267 subdistricts in Jakarta were inundated by more than 40 centimeters of water. Floodwaters caused public transportation, including the busway lines across Jakarta, to stop operations, leaving thousands of passengers stranded.

One of the major impacts of this year's flooding was the inundation of the Sedyatmo toll road to Soekarno-Hatta International Airport, which resulted in the cutting off the highway for a few days. Nearly 1,000 flights were delayed or diverted and 259 flights were canceled. The monetary losses from these delays and cancellations could reach billions of rupiah.

The Indonesia National Air Carriers Association said the loss was about Rp 40 million for each hour an airplane was stranded. The loss is greater for flights that were diverted to other airports due to the additional costs for the fuel, ground handling, navigation charge and airport charge.

The poor drainage system was blamed as the primary cause of this year's floods, as claimed by Basah Hernowo, the director of forestry and water resource conservation at the National Development Planning Board (Bappenas), and Pitoyo Subandrio, the head of the Ciliwung-Cisadane Flood Bureau (The Jakarta Post, Feb. 2).

This year's flooding was due to local heavy rainfall, and was not combined with rain on the outskirts of Jakarta. Last year, then governor Sutiyoso blamed deforestation and overbuilding in neighboring areas that were supposed to be water catchment areas for the floods. This year such blame is not present. However, the threat of neighboring areas causing severe floods in Jakarta is still present.

The annual floods in Jakarta are strong evidence that Jakarta has not been able to sustainably accommodate its growth. Two centuries ago, the Dutch colonial government, with its long experience in controlling water and drainage systems, built a canal system to protect the city's population which was then 500,000.

Jakarta, which lies in a lowland area with 43 lakes and 13 rivers, relies on the canal system to prevent flooding. Today, Jakarta is a megacity with a population of nearly 10 million within the city's boundaries and more than four million in neighboring areas; yet, it still relies on the same canal system to avert flooding.

Not only is Jakarta the capital of Indonesia, it is also the economic, commercial, cultural and transportation hub of the nation. Jakarta is the prime city of Indonesia and it dominates the urban system. The population of Jakarta is poised to grow faster than other parts of Indonesia.

The annual floods also demonstrate how growth in Jakarta confronts private consumption and public investment in infrastructure. The Indonesian economy has grown at a robust pace of 6 percent a year and Jakarta has been Indonesia's primary growth machine. New homes, commercial and office buildings have proliferated in Jakarta and its neighboring areas, but hardly any new infrastructure, including the expansion of Jakarta's canal system, has been built in the past 10 years since the economic crisis hit Indonesia in 1997.

Neither improving the drainage system nor dredging the canals and rivers is a sustainable solution for the annual floods in Jakarta. The annual floods are strong evidence that rapid urbanization in Jakarta must be reduced. One way to reduce the rapid urbanization is to eliminate the pull factor of urbanization.

One major pull factor of urbanization in Jakarta is its function as the economic, commercial, cultural and transportation hub of the nation, as well as the capital of the country. Indonesia needs to redistribute the central functions from Jakarta to other parts of the nation and create more urban agglomerations to pull urbanization away from Jakarta. Relocating central functions out of Jakarta will not only make Jakarta more sustainable, but also create regional equality in Indonesia.

The writer is an assistant professor of urban studies at Savannah State University in the U.S. He can be reached at rukmanad@savstate.edu.

[Yappofloyd]

The road to the airport was unusuable for nearly a week after the floods which is giving more priority to building the airport railway link.

Little hope for current airport road, experts say February 08, 2008 Mustaqim Adamrah, The Jakarta Post

Recent flooding that submerged part of the Sedyatmo turnpike -- the main roadway to Soekarno-Hatta International Airport -- was primarily caused by the surrounding land's inability to absorb excess water, experts concluded Wednesday. The head of the Meteorological and Geophysics Agency's climatology and air quality information division, Endro Santoso, said the land around the turnpike had lost its ability to absorb water. "The poor quality of the soil was the main cause of the flooding. Heavy rainfall was only a trigger," he said in a press conference at the Agency for the Assessment and Application of Technology (BPPT).

The agency recorded 317 millimeters of rain in Cengkareng, West Jakarta, during last Friday's downpour, more than twice the level ordinarily categorized as "very high rainfall". The flooding brought Jakarta to a standstill, submerging kilometers 25 to 28 of the Sedyatmo turnpike. Soekarno-Hatta airport detoured 58 flights and delayed another 177 leaving approximately 1,000 passengers stranded.

BPPT hydrologist Sutopo Purwo Nugroho said diminishing water catchment areas, overly exploited groundwater and population encroachment on lands adjacent to the turnpike also contributed to the flooding. "Groundwater must tightly hold every layer of soil. In the area around the turnpike, it has been pumped out in massive quantities to meet local residential demands," he said, adding that the area south of the turnpike has experienced considerable development over the past several years. "As a result, soil in the area has become more frail," he said. "The land around the turnpike subsided by 2 meters between 1982 to 1997 as structures were erected rapidly. The concave topography of the area makes the area more flood prone by preventing water from running off to the sea."

State-owned toll road operator PT Jasa Marga is planning to build elevated roads on the two sides of the turnpike as additional toll road lanes. Public Works Minister Djoko Kirmanto previously said the construction of the additional elevated lanes would start in March and was expected to be completed within a year, with Jasa Marga funding the project.

City Transportation Council member Soetanto Soehodho said elevated roads would not be a favorable solution if they were not complemented by the development railway-based transportation. "Jakarta and the Sedyatmo turnpike will never be flood-free without trains to carry passengers and goods," he said. "Elevated roads will only encourage people's dependence on private vehicles or other road-based transportation modes. Without proper infrastructure, residents and visitors to Jakarta will continue to be trapped by flooding on the turnpike."

[GWR]

Friday, May 30, 2008 1:49 PM
World Bank warns tidal flood may hit Jakarta next week
The Associated Press , Jakarta | Thu, 05/29/2008 4:15 PM | Jakarta

The World Bank warned Thursday that an exceptionally high tide could inundate the Indonesian capital next week, forcing thousands of people to flee homes and cutting off the highway to the international airport.

The situation - exasperated by global warming and the fact that Jakarta is sinking up to 2 inches (6 centimeters) a year - could mean flooding will exceed last November's roof-high levels in the hardest-hit areas, said Hongjoo Hahm, the bank's infrastructure expert.

"This is just the beginning," he said, as he pointed to homes reaching a mile (1.5 kilometers) inland that will likely be affected Tuesday and Wednesday by the 18-year semiannual tide cycle. "It's getting worse and worse."

Indonesia, a sprawling archipelago nation, is one of the world's largest contributors of carbon dioxide emissions, thanks to the rapid pace of deforestation. But experts say the country is also at risk of becoming one of the biggest victims of climate change.

Rising sea waters especially pose a threat to coastal cities like Jakarta, which has sunk at least 7 feet (2 meters) in the last three decades because of excessive ground water extraction, said Hahm.

Eventually, the government should consider building a Dutch-styled dike to protect the Jakarta Bay, he said, "but that will cost billions of U.S. dollars."

One reason for the exceptioally high 18-year tide cycles was the combination of the moon's gravitational pull and an anomaly in sea level caused by earth's own atmospheric pressure, he said. (*)
http://www.thejakartapost.com/news/2008/05/29/world-bank-warns-tidal-flood-may-hit-jakarta-next-week.html

[Yappofloyd]

^and they were correct...

Jakartans relieved as high waters recede Tifa Asrianti , The Jakarta Post , Jakarta 07/06/2008

Jakartans can let out a deep sigh of relief as high tides remain under control and sea waters recede in several areas of North Jakarta.

Yanto, an operator at the North Jakarta chapter of the Jakarta Disaster and Mitigation Taskforce, said here Friday his office had received a report that puddles in North Jakarta's Marunda subdistrict were only 10 centimeters deep in the morning. "The tide is still at a normal level, below 2 meters. The puddles of water were found in neighborhood units 1, 3, 4 and 7. We haven't heard of any flood victims," he said.

The World Bank had previously warned tidal floods could hit the coastal part of the capital as the sea level would rise by up to 1.21 meters. The city's public works agency and meteorology and geophysics agency had projected a 2.2-meter-high tide would hit North Jakarta. To prevent high tides inundating the capital, the public works agency raised seven embankments in areas prone to flooding.

In spite of the preventive measures, several areas in North Jakarta were flooded. Penjaringan subdistrict, for example, experienced 25-centimeter-high puddles of water Monday in neighborhood units 15, 17, 18 and community unit 17 near the fish auction area. The Pasar Ikan sluice gate recorded a water level of 2.06 meters, according to the Jakarta Disaster and Mitigation Taskforce.

On Tuesday, two neighborhood units in the same subdistrict were submerged in 40 centimeters of water as high tides reached 1.7 meters, the Jakarta Crisis Center reported. Besides tides, the capital has also experienced heavy rainfall in several areas recently, even though it is currently dry season.

Soetamto from the meteorology and geophysics agency said in the next 10 days, Jakarta and its bordering cities would experience mild to heavy sporadic rain. "Sporadic rain is caused by a gathering of wind from the east. The southern part, including Depok and Bogor, will receive heavy rainfall compared to other areas, while North Jakarta will probably get mild to medium rainfall. But it will not cause flooding," he said. Soetamto said rain would likely stop in mid-June and the city would enter a dry season. "The dry season will reach its peak in August," he said.

[GWR]

I initially saw this, which doesn't really give you any great clues as to what the hell it's talking about. There's an explanation further down:

Tuesday, August 5, 2008 11:05 AM
Residents make 250 biopore holes
Tue, 08/05/2008 10:08 AM | City

JAKARTA: Residents of Kelapa Gading Timur subdistrict in North Jakarta have so far completed 250 biopore holes, a city official said Monday.

"The 250 holes are scattered across nine neighborhood units, out of a total of 22 such units. We continue campaigning for biopore holes to be completed in other neighborhoods," subdistrict head Dadag Tunggul Birowo said, as quoted by beritajakarta.com.

"Biopores are important for mitigating floods," he added.

"Near the subdistrict office, we have completed 50 biopore holes in the park across from our building," he said.

One Kelapa Gading Timur resident, Rohman, said his neighborhood had 28 such holes.

"I still have space to make more. In addition, I plan to plant mango and rambutan trees," he added. --JP
http://www.thejakartapost.com/node/176766

Biopore Infiltration Holes | A Flood Prevention Method
by Syam AG | June 27, 2008 at 01:19 am
Biopore Infiltration Holes | A Flood Prevention Method by Syam AG

http://media.nowpublic.net/images//1d/c/1dcc6b0b474d95850567bbb4cb1a93bc.jpg
http://www.nowpublic.com


Rain falls and floods inundate - these are common facts of life in most regions of our beloved country. When the rainy season sets in, the fear of floods also kicks in. However, that is not the only concern that people have faced lately: water scarcity is another immense problem confronting everyone when the wet season ends and the dry season begins.

It used to be that only those people living on riverbanks had to deal with floods. However, nowadays that is no longer the case: those who live on high ground must also contend with frequent inundations since the soil has lost its ability to absorb water due to illegal logging and the construction of environmentally unfriendly buildings.

We can do several things to reduce the intensity of yearly floods.
First, plant lots of trees - this helps to preserve rainwater. Instead of cascading straight to the rivers, rainwater will be retained in tree roots, which function as a kind of reservoir during the dry season.

Second, manage your waste: proper waste disposal will reduce the occurrence of floods. If waste disposal is not managed properly, for example by dumping garbage on streets or into rivers, water sewers and canals will be blocked - the ultimate cause of floods during the wet season.

Third, build infiltration wells, which is the most suitable option for urban areas. The Jakarta Municipality Decree number 17/1992 (legalized as Jakarta municipality regulation number 17/1996), requires its citizens to build infiltration wells. However, since building infiltration wells is relatively expensive, most Jakarta citizens tend to ignore this regulation. It therefore comes as no surprise that people’s lack of awareness and participation, together with poor government regulation and legal enforcement, have caused floods to worsen every year.

The development of flood canals in the eastern and western parts of Jakarta is expected to reduce the frequency of floods. However, these canals cannot ensure that Jakarta will be free of floods altogether. People’s awareness still plays an important role in this matter; without it, floods will undoubtedly continue to inundate the city of Jakarta again and again.

A new method of flood prevention at a reasonable cost has recently arrived: unearthing soil to build biopore infiltration holes. Biopores are tunnels bored into the soil that enable organisms to become more active and plants to take root more easily. Such processes create hollow spaces inside the soil that are filled with air, and these air-filled spaces function as channels to absorb water more readily.

The more holes you bore, the better the soil can absorb water, and this minimizes the possibility of water inundating soil’s surface. As a result, flooding is reduced since the water is directly absorbed into the soil.

For optimal results, create biopores by digging vertically into the soil. Fill those holes with organic waste such as household organic scraps, cut grass and other vegetable matter. Through the composting process, these organic materials will gradually become a new source of energy for organisms inside the soil. Sufficient amounts of such organic byproducts will increase the activities of these organisms, which in turn generate even more bioporic tunnels.

Making biopore holes is more economical and less complicated than infiltration wells since they can function effectively in limited spaces. They can be created in office buildings, parks, backyards, parking spaces and in the bottom of drainage ditches. Since no sophisticated equipment is needed, they can even be dug by full-time housewives puttering around in the garden.
http://www.nowpublic.com/environment/biopore-infiltration-holes-flood-prevention-method-0

[Yappofloyd]

Caught a good Australian current affairs story last night on floods in Jakarta. Experts were stating that due to Jakarta sinking some 6 cms a year, if nothing is done to stabilise the ground water, then up to one third of Jakarta would be under water in 20 years!

Indonesia - Jakarta in Jeopardy - Synopsis
Jakarta has been a seaside city for more than 500 years. It spread over low-lying plains, criss-crossed by 13 rivers. While Jakartans accept that flooding will happen from time to time, these days it happens even when it doesn’t rain, affecting millions.400 years ago the early Dutch settlers developed a complex system of flood channels to protect the city. And now Dutch engineers are back to help out.

Janjaap Brinkman tells Thompson that many of Jakarta’s flood channels are clogged with rubbish dumped by local residents. And for a quarter of a century there hasn’t been enough dredging. Add deforestation and the development of expensive holiday villas for affluent Jakartans and the result is that when the heavy rains come the water simply has nowhere to go.

Geoff Thompson discovers that the city’s love affair with development is also contributing to that sinking feeling – on average 4-6 cm a year. Excavation for huge shopping malls and apartment blocks is depleting underground aquifers and severely compromising the very foundations of the city.

The World Bank team has a $150 million program underway to help fix Jakarta’s flood problems. Honjoo Ham says, “The weight of the city contributes to the sinking that occurs at a faster rate, but the sinking phenomenon is fundamentally because of the vacuum created underneath by the ground water extraction.”

Watch the program here; http://www.abc.net.au/foreign/content/2008/s2368261.htm


Flood canal land buy-up proceeds but disputes loom - by Tifa Asrianti , The Jakarta Post 24/09/2008 To make the completion of the East Flood Canal construction possible, the city administration is distributing payments in the next couple of weeks to acquire 247 plots of land of the 254 plots targeted in East Jakarta this year.

Governor Fauzi Bowo said Tuesday his administration was still processing the property titles on the additional 718 plots scheduled for acquisition in East Jakarta. "We have allocated Rp 138 billion (US$14.79 million) to pay for the land. Today, we are scheduled to make payments on 17 plots, but one was represented only by the owner's heirs, so we could only pay 16 owners," Fauzi said during land payment and deed transfer at the Jatinegara district office.

The acquisition of 17 plots of land, which encompass 2,106 square meters, required Rp 6.2 billion. The 17 plots are located in two subdistricts: 11 in Cipinang Muara and six in Cipinang Besar Selatan. Fauzi said the land committee should inform the owners about the procedure as owners must walk the transfer process through 11 desks.

M. Arifin, East Jakarta municipality secretary, said the tax office would automatically subtract outstanding taxes from the land payment if the owners had been negligent in paying land and building taxes. He said his office would hold acquisition sessions Thursday and Friday to pay for 116 plots of land covering 27,581 square meters in Pondok Bambu, Duren Sawit and Malaka Sari and 114 plots, 23,945 square meters, in Malaka Jaya, Pondok Kopi and Pulogebang. "After receiving the payments, the land owners have 14 days to raze their homes and leave the land," he said. Land owner Zeid Mashur said he would use the money to buy a new house for his family. Zeid, who has a certificate for his 200-square-meter plot, received Rp 600 million in payment.

Zeid said he had been waiting for the payment since 2007. "I hope now the administration can speed up payment for others." Arifin said the land acquisition had hit a snag due to unclear titles: Some of the residents were without certificates. He said his office would consign the disputes to the courts for resolution.

The East Flood Canal project requires tracts of land in East and North Jakarta. East Jakarta counts 965 plots of land to be acquired, North Jakarta, 716. City Secretary Muhayat said the East Flood Canal would be the primary flood control mechanism for East and North Jakarta. He expected the land payments to finish before Idul Fitri even though the canal construction has not been scheduled to begin until 2010.

He said the administration had prepared 3,500 officials from crisis centers and NGOs to get through the regular annual flooding. "We will hold disaster awareness week at national Monument (Monas) park Oct. 21 to 27. The crisis centers must involve the public in mitigation rehearsals to raise their awareness," he said.

Besides Jakarta's investing in flood control infrastructure, the central government has borrowed US$150 million from the World Bank to carry out river dredging on a large scale in the capital.