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Jakarta · Social Business · Sebastian Csulits · Groundwater Reduction

Jakarta is sinking because too much water is taken from below.

RainBank helps kampung communities replace part of their daily non-drinking water demand with harvested rainwater — reducing pressure on groundwater, one hub at a time.

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Cause and Effect

Jakarta's water problem is a groundwater dependency problem.

01

Limited piped water access

02

Household groundwater pumping

03

Aquifer pressure drops

04

Land subsidence accelerates

05

Flood risk increases

06

RainBank reduces demand at the source

About RainBank

A community water hub designed for one clear purpose.

RainBank Jakarta is a Social Business concept based on Muhammad Yunus' principles. It reduces groundwater extraction by harvesting rainwater for non-potable household use: showers, washing, toilet flushing, cleaning, and community facilities. Drinking water remains sourced through existing safe channels.

01

Reduce Groundwater Extraction

Jakarta's land subsidence is strongly linked to groundwater pumping. RainBank offsets selected daily uses with harvested rainwater, reducing demand where it begins.

02

Community-Owned Hubs

Collection is anchored to trusted buildings such as mosques and schools. Storage, distribution, and maintenance are handled locally by a trained operator.

03

Pilot-Ready Social Business

Setup capital funds the first hub. Small access fees and service agreements cover operations, operator income, maintenance, and eventual capital recovery.

The Numbers

The scale of the crisis

0%

of Jakarta residents lack access to clean piped water

Source: World Bank, 2024

0cm

per year — how fast North Jakarta is sinking

Source: MDPI Water Journal, 2024

more expensive — vendor water vs. piped water price

Source: The Conversation, 2023

Explore

Everything you need to know

01

The Crisis

Why Jakarta's water problem is really a groundwater dependency problem — and what it means for the city's future.

Read more

02

How It Works

From rooftop to community tap. The RainBank Hub explained as a practical, low-tech local infrastructure system.

See the system

03

Our Impact

How one hub can reduce groundwater demand, improve access for non-potable uses, and support local operator income.

See the data

Our Mission

"RainBank reduces groundwater extraction by replacing non-potable water demand with harvested rainwater."

The first pilot is designed to test what a hub can reliably offset: washing, cleaning, toilet flushing, showers, and mosque or school use during rainy and high-availability periods.

Discuss a pilot hub