Semarang climate adaptation

Posted on 18 September 2014

Pioneer in climate change resilience 

Pioneer in climate change resilience

Already facing flooding, coastal erosion, drought, and landslides, the city of Semarang, Indonesia, National Earth Hour Capital 2014, is becoming an Asian pioneer in climate change adaptation and resilience. As one of the ten core cities in the Asian Cities Climate Change Resilience Network, Semarang has completed a vulnerability assessment and launched a number of projects, including a flood warning system, rainwater harvesting, and mangrove planting. Semarang has also invested in green procurement, bus rapid transit, and a switch to LEDs for public street lighting.

Semarang was awarded the title Global Earth Hour Capital in Earth Hour City Challenge 2014

Keywords: climate change adaptation, ACCCRN, resilience, flood warning, rainwater harvesting

With the effects of climate change already visible, and in the absence of a substantial international mitigation agreement, many cities have started to highlight adaptation and resilience. The UN global campaign Making Cities Resilient has, in a few short years, managed to convince more than 2,000 cities to sign up to systematically reduce urban risks from disasters (see also UN).

In addition the Asian Cities Climate Change Resilience Network (ACCCRN), a network funded by the Rockefeller Foundation, is “experimenting with a range of activities that will collectively improve the ability of the cities to withstand, to prepare for, and to recover from the projected impacts of climate change.” The network was founded in 2008 with ten cities in India, Indonesia, Thailand, and Vietnam, and has since been expanded with another 20, including some in Bangladesh and the Philippines. The goal is to find good practices that build climate change resilience for poor and vulnerable people, and to spread the practices to other cities.

Severe environmental pressures
As one of the core cities of ACCCRN, Semarang is the capital and largest city of Central Java, Indonesia, a major port city with 1.5 million inhabitants (5.5 million in metro), with manufacturing and tourism as the primary industries. Semarang is already experiencing severe environmental pressures, including storms, floods, landslides, sinking and inundated lands, coastal erosion, and drought and depleted water supplies – all problems that are exacerbated by climate change (see also New Orleans). Like Venice and Mexico City, Semarang has been called a sinking city, with scientists estimating land subsidence rates of as much as 10 centimeters or more per year.

Semarang started its work with ACCCRN with capacity building, initiating a dialogue with stakeholders and establishing a city team on climate change adaptation. Next, the city carried out a comprehensive vulnerability assessment and a city resilience study that identified the four top climate hazards of inundation and flooding, coastal erosion, drought and landslides. These are to be combatted via a number of pilot projects: seawall construction, mangrove planting, a stakeholder platform, housing renovation with microcredits, adaptive measures against landslides and drought with warning systems, and plantations.

Multiple adaptation actions
The vulnerability assessment identified and ranked adaptation actions such as rainwater harvesting, flood shelters, institutional development, liquid waste management, master plan revision, education, water saving, private sector involvement, purification of water sources, slope planting, creating a green belt of plants along shores, river conservation, diversification of marine and fisheries businesses, neighborhood drainage systems, a citywide rainwater channel belt, seawater desalination, and a sea wall.

The Semarang city team is already working to include climate change resilience goals in the city´s medium term development plans, and has started the two projects with highest priority - rainwater harvesting and flood shelter.

Rainwater harvesting and flood warning
Almost half of the population is not served by municipal water authorities and are vulnerable to disruptions of clean water, contamination in floods, loss of groundwater, and drought. The city has so far built almost 100 rainwater harvesting systems, both on a household and communal scale and some for school buildings (see also Singapore). Providing clean water to poorer communities will also reduce groundwater exploitation that speeds up land subsidence.

In cooperation with government agencies, experts, and other stakeholders, Semarang is developing a flood early warning system which will include evacuation plans and flood shelters. It will reduce climate change vulnerability and disaster risk, and enable the community to prepare measures to reduce damages. The Public Works Agency will be better informed about areas where infrastructure capacity needs to be strengthened in order to minimize the flood impact.

The continuing work on a sea wall with mangrove planting goes back to 2002 and has already reclaimed half of 196 hectares of lost fishponds (see also Brisbane). The national project of the Jatibarang dam, which is set to begin operation in 2014, is expected to reduce flooding, improve the drainage system and deal with the problem of clean water as limited water supply leads to uncontrolled exploitation of groundwater that in turn speeds up subsidence.

Urban resilience pioneer
In 2013, Semarang was one of the first 33 cities worldwide to be selected by the Rockefeller Foundation’s 100 Resilient Cities Centennial Challenge that awards cities who have "demonstrated a dedicated commitment to building their own capacities to prepare for, withstand, and bounce back rapidly from shocks and stresses" (see also Chengdu).

Semarang has also launched other sustainability projects, including green procurement, bus rapid transit (BRT), and public lighting replacement.
  • The city has a green procurement policy for all government purchases, with criteria that include energy efficiency and recycled material requirements. The policy also has specific emissions reductions goals for certain types of appliances, such as reducing emissions from air conditioner use by 30%.
  • Semarang currently operates two BRT corridors, with a further six corridors planned for completion by 2020. The system is part of a wider modal shift strategy that also includes wider collection of parking fees and a Car Free Day on Sundays.
  • The city has launched a program to replace 30% of park and street lighting with LED lights. In a previous pilot light replacement project with the private sector, a 33% reduction in emissions from lighting was achieved.

Gunawan Wicaksono, Environmental board Semarang municipality, “Urban Climate Change Resilience in Semarang – Indonesia”,

Asian Cities Climate Change Resilience Network (ACCCRN), Semarang,

Semarang ACCCRN City Team and Mercy Corps, “Semarang Climate Change Resilience Strategy, Indonesia”,

United Nations Population Fund (UNFPA) and The International Institute for Environment and Development (IIED), “Climate vulnerability and adaptation in the Semarang Metropolitan Area: a spatial and demographic analysis”,

carbonn Climate Registry, City Climate Report: Semarang,

The Rockefeller Foundation, 100 Resilient Cities,

The Jakarta Post, “Jatibarang Dam to begin operation soon”, May 21 2013,

The Jakarta Post, “Semarang joins the ‘sinking cities network’”, October 06 2012,

Text by: Martin Jacobson

Land subsidence in Semarang
© Semarang Municipality Environmental Board
National EHCC Capital 2014 – Semarang