Indonesia: To minimize flooding residents urged to build wells, biopore holes

Dewanti A. Wardhani, The Jakarta Post 12 Nov 15;

As the rainy season approaches, residents are being urged to take part in efforts to minimize flooding.

Hydro-geologist Fatchy Muhammad of the Indonesian Water Society said many residents were still unaware that rainwater should be managed vertically, not horizontally.

“Most people think flooding occurs because the waterways are not wide enough. Hence, a majority of residents still wait for the city administration to widen the rivers and sewers to prevent flooding. This is a fatal mistake,” Fatchy told The Jakarta Post on Wednesday.

Instead, he said, rainwater should be stored for the dry season. To store rain water, Fatchy said, middle-upper class households could develop absorption wells, while lower-class households could provide biopore holes.

An absorption well is an underground chamber that collects rainwater and allows it to seep into the soil gradually and reduce runoff. By constructing an absorption well, rainwater could be saved as a water reserve to help fill the empty pores underground as a result of groundwater depletion.

Meanwhile, a biopore hole not only helps to absorb rainwater, but also functions as a waste management system for organic waste. A biopore can be made easily using a manual drill, a pipe and a manipulatable metal stick.

“It’s time that we make use of rainwater. We need to change the mind-set that rainwater needs to be got rid off,” Fatchy said.

Architect Susiadi Wibowo said absorption wells could greatly help the cycle of hydrology, which had been disturbed due to a lack of soil surface. He added that existing sewers, canals and rivers could not accommodate the volume of water, causing overflow.

He said that every type of soil was different, therefore each warranted wells of different sizes.

“For example, saturated soil only needs a small well or none at all. For conservation, one can use a bucket to store water. Meanwhile, soil of low water seepage quality needs a deep well,” Susiadi said.

Separately, Jakarta Water Management Agency head Tri Djoko Sri Margianto said that if developing absorption wells and biopore holes was too difficult or costly, residents could simply stop littering.

“Absorption wells and biopore holes greatly help reduce water loads produced by the rain on our waterways. This will also reduce the possibility of overflowing waterways and can minimize flooding. These systems are affordable for the middle class,” Tri told the Post on Wednesday.

He pointed out that garbage often clogged up waterways and jammed pumps, which could result in flooding similar to that seen at Central Jakarta’s Dukuh Atas underpass last weekend.

“Disposing of waste in the right place is a small step that goes a long way,” Tri said.

He also revealed that the city administration starting next year would carry out a citywide zero-runoff program starting in public schools, especially in South Jakarta. Further, Tri said, all developers seeking to construct a building had to have a zero-runoff design starting next year.

Although building owners are mandated to develop absorption wells to equip all buildings as stipulated in Gubernatorial Regulation No. 68/2005, Tri acknowledged that many still did not comply with the regulation, while others provided such infrastructure as a formality, without ensuring it actually worked.


Government to build two dams to control floods in Jakarta
Antara 13 Nov 15;

Jakarta (ANTARA News) - The government will build two dams in West Java as part of its efforts to control floods in Jakarta, Public Works and Housing Minister Basuki Hadimuljono stated.

"The two dams called Sukamahi and Ciawi will be built in 2016," the minister stated during a coordination meeting with stakeholders in Jakarta on Thursday.

Also present at the meeting were members of the Regional Representative Council (DPD) of Jakarta province, including A.M. Fatwa, Fahira Idris, Dailami Firdaus, and Abdul Azis Khafia.

Chairman of the Jakarta Provincial Legislative Council (DPRD) Prasetyo Edi Marsudi, Secretary of the Jakarta Provincial Government Saefullah, and Deputy Governor for Demographic Control and Resettlement Syahrul Effendi also attended the meeting.

The government is in the process of clearing land to build the dams, Basuki revealed.

Flooding is a problem that recurs every rainy season, he pointed out.

"The central government is striving to overcome floods in the capital by building dams in the upper reaches of the rivers, which flow into Jakarta," he remarked.

If the dams are built in the upper reaches of the rivers, the flow of water can be diverted to the dams during the rainy season, and the water will not entirely flow into Jakarta, he explained.

The minister further stated that the government will also build low-cost flats in Pasar Minggu and Pasar Rumput, South Jakarta, to meet the demands of the people belonging to the low-income group, he added.(*)


Authorities, residents gear up for floods, landslides
Slamet Susanto and Agus Maryono, The Jakarta Post 13 Nov 15;

Local authorities in landslide-prone regions of the country are bracing themselves for the beginning of the rainy season by installing early warning systems (EWS) and conducting campaigns to improve residents’ awareness.

In Yogyakarta, the provincial administration has installed hundreds of EWS units in areas considered at risk of landslides as well as those prone to cold lava floods from Mount Merapi.

“We have installed some 300 EWS units to help anticipate [catastrophes] and to minimize casualties,” Yogyakarta Disaster Mitigation Agency (BPBD) emergency section head Danang Samsu said on Thursday.

Danang said landslides posed serious threats during the rainy season, as there were many landslide-prone hills in the province, especially in Kulonprogo regency.

Some 200 of the 300 installed EWS units were stationed in Kulonprogo, he added.

Separately, Yogyakarta Geological Disaster Technology Research and Development Center (BPPTKG) head I Gusti Made Agung Nandaka said the rainy season could trigger cold lava flows from the slopes of Mt. Merapi, one of the world’s most active volcanoes.

After its latest eruption in 2010, Mt. Merapi, according to Nandaka, still has over 40 million cubic meters of volcanic material scattered on its slopes.

“Most of it is located on the southern and western slopes of Merapi,” Gusti said.

Lahar floods from Merapi had previously damaged hundreds of houses in Sleman regency, Yogyakarta, and Klaten and Magelang regencies in the neighboring Central Java province.

After a prolonged dry season triggered by the El Niño wheather phenomenon, a number of regions in Indonesia entered the rainy season this month.

Earlier this week, the Meteorology, Climatology and Geophysics Agency (BMKG), warned that several parts of the country, including North Sumatra, West Sumatra, Bengkulu, Jambi and South Sumatra, would be prone to floods due to a series of heavy downpours in the regions.

Meanwhile, some other regions, including Bengkulu, Aceh, southern parts of West Java, parts of Central Java and West Nusa Tenggara, were prone to landslides.

To follow up the warning, the Banjarnegara regional administration in Central Java has established so-called disaster resilient community groups in 13 of its 20 districts. Among the 13 districts considered prone to landslides are Punggelan, Sigaluh, Pagedangan, Madukara and Klampok.

Banjarnegara Regent Sutedjo Slamet Utomo said the groups had been tasked with mapping the landslide-prone areas in their respective region and detailing action needed to prevent landslides.

“All the landslide-prone districts in the regency, for example, need gabions to buttress steep slopes in anticipation of landslides,” Sutedjo said, adding that his administration had distributed gabions to the areas in need.

Some 70 percent of Banjarnegara lies on hilly terrain, making it prone to landslides, particularly during the rainy season.

The latest deadly landslide in the regency took place in December last year in Jemblung village, Karangkobar district, burying 108 people along with their houses.

Meanwhile in West Sumatra, heavy rain in South Pesisir regency on Wednesday triggered a landslide that blocked the access road to Taratak Tampatih village in Batang Kapas district, leaving more than 800 residents isolated.

“The traffic to the village is still cut off,” Zaimal Yunis of Taratak Tempatih told the Antara news agency on Thursday.