Soggy Cities, Entry 1: Semarang

There is a gritty charm to this industrious city on the coast of North Central Java. Established as a colonial town by the Dutch East India Company (VOC) in 1702, Semarang proper has a population of approximately 1.7 million people, with several million more living in surrounding areas. The lives of many are affected by tidal flooding; during the rainy season, there is flooding along rivers, flash floods, and the threat of landslides in the upland areas. All of this is exacerbated by subsidence rates in some coastal areas of more than 15cm annually and the mounting threat of sea level rise. During the last decade, the city has raised streets and essential infrastructure. Businesses have relocated or been abandoned. Residents who could afford to keep pace raised their homes; those who couldn’t step down into sunken houses through doorways half their former height. For a while, the future of Kota Lama (old city), consisting of more than 100 colonial era buildings, the greatest concentration in all of Indonesia, and Pecinan (Chinatown) hung in the balance as citizen preservation groups rallied public support and prevailed on the city to determine whether restoration could be coordinated with flood protection. 

A signal moment in Semarang’s soggy history was the creation of the Banger Polder, completed in 2016. In partnership with the district water authority of Rotterdam, the city and the 85,000 residents of a low-income urban area plagued by tidal flooding instituted a Dutch style polder—an artificially maintained hydrological regime—that secured “kaki kering untuk semua” (dry feet for all). The infrastructural intervention was modest—reinforcing dikes, installing an earthen dam and a pumping station—but it went together with an experiment in citizen governance, based on the polder model as social institution. “Polder” is a popular word in Semarang and the coastal stretch of the city is now divided into four polders, each with a dedicated flood canal, sea wall and pumping station. Major national projects, including a toll road cutting through the sea that will double as sea wall, seem bent on converting much of the coastal plain into a polder. 

Polders buy time, but their water defenses subside just as quickly as undefended ground. If Semarang does not get a handle on subsidence, the Banger Polder will have outlived its usefulness in ten years and tidal flooding will return. Everything depends on stopping subsidence. The major cause is unregulated ground water extraction, primarily by industry, but also by hotels, universities, residents, and the city itself. The public water supply meets only 20% of the city’s needs. Enforcement of regulations in the absence of sufficient supply is impractical. Through Water as Leverage, a comprehensive, multi-faceted plan is being developed that involves local, provincial, and national planning agencies, impacted residents and businesses, neighborhood organizations, local non-profits, universities, an artists’ collective, Wetlands International and the Nature Conservancy, as well as international design teams. Under the banner of a design variant of the Javanese phrase “Bhinneka Tunggal Ika” (unity in diversity), One Resilient Semarang aims at enabling communities and industries to reduce their reliance on ground water through rainwater retention and water recycling on a local level while strengthening their communal identity and resilience. Concurrently, there are efforts afoot to leverage large capital projects by fusing green and blue infrastructure (mangrove reforestation and sediment capture) with grey in an integrated coastal protective zone.

Michael Kimmelman’s harrowing report on Jakarta in a widely-read NY Times article, “Jakarta is Sinking So Fast, It Could End Up Under Water,” gave that city ten years to save itself. Semarang is working under similar time pressure. Both are cities to watch as harbingers of our soggy urban future. Thanks to the deep cultural resilience of its citizens, there’s a good chance Semarang will succeed.