Project: Cascading Semarang

The Cascading Semarang team features experts from the Netherlands and Indonesia with considerable experience in Semarang. The team partners have collaborated on previous projects both as companies and individuals. The team as a whole is divided into several tracks:

The Urban Track features MLA+ and FABRICations as the core team, supported by Liveable Cities and local universities (UNDIP, UNISSULA) who are working on community development initiatives.

The Water Track is led by Deltares with support from Witteveen+Bos and the universities UNDIP and UNISSULA.

The Business Case Development Track is also led by Deltares. Their international expert in financial and economic analyses and innovative financing structures is the primary leader with support from Witteveen+Bos.

The Communication, Stakeholder and Community Involvement Track is led by Roy Kraft van Ernmel in collaboration with UNDIP and supported by all partners.

The knowledge exchange and capacity building aspects of the projects are led by students and experts from universities in the Netherlands (TU Delft, Academy of Architecture Amsterdam and Radboud University) and Indonesia (UNDIP and UNISSULA among others).

The Cascading Semarang team created proposals for three different water resilience solutions in the city of Semarang.

A full watershed approach has been taken that devises solutions for upstream and downstream areas alike. The concept of a ‘cascading’ planning strategy has been added to describe the series of elements that work together synergistically as part of this overall plan. The team's proposal shifts the water management paradigm in Semarang from “Get all the water out” to “Not a drop of water gets lost”.

Designs are specified for mountainous upland areas, heavily urbanized surface water in the mid- and downstream areas, and in the industrial areas along the coast. Interoperative components not only on work to prevent flooding in Semarang, but also to foster new opportunities for watershed-scale water management. Their proposal does so by creating a resilient network that improves water management practices, boosts the local economy and empowers vulnerable communities. The proposed projects are designed in close collaboration with the local communities to promote cultural awareness and a healthy water metabolism.

Cascading Semarang: Feeding the Industry tackles the provision of secure and readily accessible alternative water sources for industrial purposes in Semarang.

In the western part of Semarang, the main industrial areas of Wijaya Kusuma, Tambak Aji, and Candi are simultaneously facing challenges from sinking ground and rising tides. Currently, most industrial operations use water extracted from the aquifer, a process which is accelerating land subsidence and exacerbating the risk of pluvial and marine flooding. At the same time, commercial and industrial activity is expanding quickly in the coastal plain. The main goal of this proposal is to shift the industrial water consumption paradigm in Semarang, which will benefit citizens and private industries alike.

Cascading Semarang: Feeding the Industry proposes that multi-purpose infrastructure be installed to provide critical water supplies to industrial operations and create additional co-benefts. Strategies include a combined roadway-dike structure, water retention areas, and strategic separation and use of water by quality in select test locations in the western part of Semarang. Ultimately, the plan aims to reduce or altogether stop the extraction of groundwater from the aquifers for industrial use and thereby mitigate land subsidence concerns.

Cascading Semarang: Rechanneling the City aims to improve water management in the inner city, creating additional capacity for water storage and regulation of waterflow.

The proposed system promotes handling stormwater locally instead of discharging water as fast as possible, which reduces pluvial and fluvial flood risk downstream. Upgrades to existing water infrastructure improve sanitary conditions in the city through programs like solid waste management, harvesting materials and energy, and the installation of public facilities. The project creates synergetic community hubs geared toward stimulating new commercial and residential development in the city center.

The Rechanneling the City concept is designed to reinforce a network of water infrastructure that provides greater water storage capacity, better control of water flow, and more permeable surfaces throughout the city and the surrounding areas. At the same time, it addresses water quality issues by improving the capacity for waste management, and therefore improves overall environmental quality and truly embeds the surface water system within the urban fabric.

Cascading Semarang: Spongy Mountain Terraces proposes the installation of upland interventions designed to reduce the risk of flooding and landslides in downstream areas.

The goal of the project is to enhance the natural sponge-like capacity of uphill zones and stimulate the development of new urban typologies that facilitate living with water. In ecological zones and productive landscapes, the natural spongy capacity of the uphill area is enhanced with natural infrastructure. The negative effects of urbanization from new residential development are minimized by water retaining infrastructure systems and green corridors. Improved accessibility to water sources also increases the quality of life for more vulnerable groups. Excess water that cannot be locally stored or consumed will be transported via rivers and canals to larger retention areas for industrial water use. The Spongy Mountain strategy also generates additional value for the well-being of local communities, biodiversity, sustainable energy production and waste collection.

The implementation of the spongy mountain concept requires custom regulatory mechanisms, including policy adjustments and/or providing developers with reductions and allowances to acheive desired effects. Two project sites (Sadeng and Tembalang) have been chosen as testing areas for these concepts.