Deep in the Rewa Delta on Fiji’s largest island, Viti Levu, the river gradually clawed away at the banks, finding its way into the villages, destroying food gardens and threatening local homes.

For the villagers of Nalase, the situation had become dire. Water lapped at the floorboards of the community hall and seeped into houses at high tide.

Even the cement walls erected along the riverbanks failed to hold, sliding into the mud and disappearing under water.

Sitella Rasiga – pursuing a Diploma at the Pacific Theological College – recognized the existential threat posed by climate change from lectures.

“Suddenly, all that we had been learning about just came to life in front of my very eyes,” Rasiga said.

“I’d gone to the village for a four-week research stint and the riverbank had started to slide into the water. At high tide we could hear water touching the floorboards and the grass was dying.’’

The villagers had exhausted every means possible in their attempts to hold back the onslaught of the constantly rising river.

A cement wall funder by the Fijian government and floodgates provided by the European Union crumbled and buckled. Villagers resorted to filling bags with sand but the relief was temporary.

With each receding tide, bags were dragged into the river to add to the silt of hundreds of years.

Rasiga recalled the moment the solution to the villagers’ climate change issues became glaringly obvious.

“The young people had gathered in the community hall after filling sandbags and shoring the river defences,” she said.

“Our elders were talking about the failure of the system and how despite the abundance of knowledge and technology, nothing could hold back the force of nature. Then, I asked about ancient knowledge. You know, the wisdom of our ancestors.

“Nothing had prepared me for the response of the older villagers.’’

Dredging the depths of their fonts of knowledge, the older villagers remembers the lessons taught by their grandparents and great-grandparents.

For generations the people of Nalase have dwelt in the delta where the waters of the sea meet the waters of the Rewa River with its source deep in the mountains of Viti Levu. In this ancient place, water has been blessing, curse and reality for millennia.

“To hold back the river, our forefathers and foremothers used an engineering system which came from observing plants, the river and the cycle of life,’’ Rasiga said.

“It’s called Nana (Mother) and involves planting stems of the tiriwai (a small mangrove variety) about a meter into the river. These stems form a wall which is  held together by vines.

“Between the wall and the riverbank, we place cut grass, leaves, branches and other biodegradable materials which rot and form a new strip pf land. It’s natural reclamation!’’

As the tiriwai stems take root in the river, they develop root systems which interlock and then collect mud and silt to form a wall underwater. This complex root system helps ensure the integrity of soil on the riverbank. Now secure, it does not slide into the water.

Inspired by their newfound knowledge, the village people set to work immediately under the supervision of the elders in a practical, meaningful exercise in intergenerational knowledge sharing.

The neighbouring village, Vunisinu) observed the project and put in place similar measures to protect their homes.

“We had become so focused on Western models of development and climate change mitigation that it was not possible for us to see that our solutions existed within the community,’’ Rasiga said.

“It’s been a really steep learning curve for the young people but they have an appreciation for local knowledge now. And they see why this method is called Nana (Mother). Our mothers teach, nurture, and protect – that’s exactly what our traditional wall is doing – it’s protecting us against climate change.’’

In December Rasiga will lead local youth groups at Nalase and Vunisinu in the second stage of their riverbank protection project.

Self-funded, the villagers have pledged to do all they can without relying on outsiders for help. This phase is expected to take three months.

Rasiga said she hoped other villagers would learn from the example of Nalase and Vunisinu.

“There are other ancient methods of environmental protection out there,’’ Rasiga said.

“For those methods to work, young people must listen and our elders need to share. The task of saving our villagers and resources from climate change is an intergenerational duty and we need each other.

“Mutual learning and mutual respect – those are the keys.’’

This is a story grant supported by Earth Journalism Network.