Planting trees to help restore the Citarum River watershed

Revitalizing a crucial watershed

The Citarum River in West Java, Indonesia, has played a vital role in the countryside for generations, among other uses providing irrigation for rice paddies and energy from three hydroelectric dams along the river. Unfortunately, the river has also been subject to misuse as waste disposal for decades, leading to it being one of the most polluted in the world. Since 2011, the Indonesian government has been running a revitalization project over 180 kilometers of the river’s length with the goal to restore the water to clean drinking quality.

Restoring the river extends beyond its banks to the whole area drained by the river—its watershed. One important aspect of restoration involves planting trees to renew the forests that have been cut down. Forests improve water retention, reduce surface runoff—including pollutants and trash—from reaching the river, and prevent erosion, among other benefits.

Reforesting through local partnerships

Trees4Trees typically spends a minimum of five years in any given area to establish the planted trees and educate the community on the benefits of rehabilitation. “It’s a big reeducation project,” said Trees4Trees founder Mark Schmidt. “Indonesia is a really challenged place in regards to forestry; they are cutting down trees at a break-neck pace and we are trying to do our part to return those trees.” In 2022, Trees4Trees planted 3 million trees.

One Tree Planted connects community-based organizations like Trees4Trees with sponsors like Microsoft. “We are very much a partnership driven organization,” said Nils Saha, an urban forestry project manager for One Tree Planted. “We source these projects and bring on local partners based on the priorities and needs of the community lead.”

Conversations with local government and site surveys with the Greenland International Industrial Center (GIIC) and Karawang International Industrial City (KIIC) estate management that hosts Microsoft datacenters led to an agreement for Trees4Trees to plant 22,800 trees in collaboration with Microsoft and One Tree Planted. Many of the trees in the GIIC project are fruit trees that the community and farmers will be able to harvest for free. Among the 23 different kinds of native fruit trees that Trees4Trees plants are avocado, durian, plum mango, and jackfruit.

Bringing community volunteers together

In 2023, volunteers from the Microsoft subsidiary office in Jakarta helped One Tree Planted and Trees4Trees to plant 1,452 trees, helping to reforest a riparian zone, prevent erosion, and improve water quality for the 1,000 local community residents surrounding the campus.

In November 2024, a volunteer tree-planting event hosted by One Tree Planted and Microsoft had more than 100 attendees in the GIIC. More than 600 native Jakarta trees were planted to sustainably support the local ecosystem. Volunteers came from community stakeholders: general contractors, datacenter operations and community development teams, headmasters and teachers from schools supported by the Digital Skills Fund, and community partners.

“Participating in planting 600 trees such as jabon, sengon, suren, and johar strengthens our awareness of pressing environmental issues while encouraging our commitment to continue contributing to creating sustainable solutions for a greener future,” said volunteer and PT Jaya Obayashi corporate communications officer Ramdan Kusyani. “Thank you, Microsoft Indonesia!”

Looking to a greener future

These trees are expected to absorb approximately 87.5 kg of carbon dioxide from the atmosphere throughout their lifespan, according to the 2024 Trees4Trees impact report. Other benefits include improved soil health through decomposing leaves and strong root systems, enhancement of biodiversity of habitat and food sources, reduction of air pollutants in urban environments, and increased canopy cover that will contribute to urban cooling.

“This tree planting activity is very interesting and beneficial,” said volunteer and environmental officer for Leighton Contractor Indonesia, Hisyam Adnan. “This is because Microsoft, as a client, involves [general contractors] in this activity to increase awareness of all elements of the global issue of global warming.”

In the last year, Microsoft has planted more than 20,000 trees in the GIIC and KIIC areas with One Tree Planted. With support from Microsoft, Trees4Trees will continue their forestry efforts in urban areas around Jakarta to improve communities and establish environmental education. See what the project has accomplished so far, and what its goals for the future are, in this impact report .