Padi Raya Street Semarang Floods Reveal Inhibition Gaps, Says Ex-Civil Engineer

VANIA ANDANI PURDA (30802300005)

Reported by Vania on Sunday, November 5, 2025

Figure. 1

Nearing the aftermath of the flood in the Padi Raya Street

Semarang, Central Java -- In the aftermath of the gruel of the late October flood that hunted Semarang, many of  its residents were left clearing sewage water from homes and navigating lingering puddles. Turning the next week's daily routines into a slow recovery effort, it adds such urgency for people to call for better preparedness.

Former civil engineer Purwanto (37), who previously worked at PT Wijaya Karya, shared his views on why the prolonged flooding that struck Padi Raya Street from October 22 to November 4, 2025, may continued for many days, what factors worsened the situation, who should have coordinated the response, where the issues were most visible, and how future flooding might be prevented.

Figure. 2

Picture of Mr. Purwanto and Vania (Interviewer) on his house 

Purwanto believed that the flood was prolonged due to no proper coordination among government agencies, including the Central Java Governor’s office and national disaster management institutions. Unlike previous floods, which typically receded within some days, the recent disaster lingered because there was weak coordination that is causing delays in response.

"[...] Menurut pendapat saya, atas peristiwa banjir yang terjadi selama hampir satu minggu lebih ini, memang dirasa kurang adanya koordinasi antar instansi dimana satu sama yang lain [...] sehingga terjadinya banjir di Jalan Padiraya ini berlarut-larut tidak seperti yang sebelum-sebelumnya [...]".

Beyond poor coordination, he noted that extreme rainfall and the annual land subsidence along Java’s northern coast significantly increased flood risk. This subsidence must have pushes the seawater level higher, making low-lying regions more vulnerable to the disaster.

"[...] Kalau dilihat dari kondisi yang memang sekarang ini, kan cuaca ekstrim curah hujannya sangat tinggi. Kemudian ada beberapa hal yang perlu kita cermati, bahwa memang daerah pantai utara Pulau Jawa ini mengalami penurunan tanah kira lebih sekitar 7 cm per tahunnya [...]" Purwanto pointing to several contributing factors when asked for a main cause.

He emphasized that policy makers should prepare more seriously for future flood scenarios, including tighter coordination with the Meteorology, Climatology, and Geophysics Agency (BMKG). Since BMKG can forecast extreme weather, its predictions should guide faster and more synchronized disaster responses at all levels.

"[...] perlu ada pemikiran-pemikiran khusus dari para pemangku kebijakan yang terkait, seperti dari pemerintah pusat maupun daerah khusus untuk menyoroti (dan) [...] mengatasi banjir yang akan datang. [...] Perlu adanya koordinasi dengan BMKG yang selama ini sudah berkecimpung ahli dalam bidang masalah percuacaan [...]".

He advised the public, like the residents in flood-prone areas, to strengthen community preparedness, such as to raised house elevations, avoid littering to allow drainage to work properly, plant more trees, and protect groundwater absorption areas rather than paving everything with concrete.

"Mungkin untuk para warga yang tinggal di daerah langganan banjir sudah harus mempersiapkan diri [...] seperti mungkin melakukan peninggian rumahnya, [...] tidak membuang sampah sembarangan sehingga drainasenya itu akan berjalan lancar, [...] kemudian juga untuk lebih memelihara lingkungan hidup seperti menanam pohon, [...] tidak menutup ruang resapan air untuk masuk ke dalam tanah seperti jalan-jalan yang di beton [...]" Purwanto on providing his probable solutions based on his engineering background.

He stated that excessive groundwater extraction, especially from deep wells, accelerates land subsidence because removing underground water causes soil layers to sink. Instead, he encouraged optimizing the city’s Regional Drinking Water Company (PDAM) to supply surface-processed water, reducing the public’s need to drill private wells.

"[...] tanah itu akan turun, [...] (menaikkan) permukaan mata air sehingga efeknya tanah itu akan amblas ke dalam. Tanpa air tersebut tanah akan lebih menurun karena beban tidak ada yang menahan, karena airnya sudah sedut untuk memakan warga yang secara besar atau tidak terkontrol." Purwanto explained.

"[...] Harusnya itu kita kan sudah ada instalasi PDAM yang mengolah air permukaan untuk bisa digunakan oleh masyarakat. Mungkin itu lebih baik untuk PDAM-nya bisa lebih dioptimalkan untuk dapat mensupply kebutuhan air para warganya sehingga tidak ada melakukan pengeboran air tanah dengan air dalam." Purwanto added.