By Charity Mukono
Joseph Nguthiru had never thought much about water hyacinth. Growing up in Eastlands, Nairobi, lakes and aquatic ecosystems felt distant.
Then, during a field visit to Lake Naivasha with classmates from Egerton University, a boat carrying them came to a halt.It was not an engine problem.
The boat was trapped in a dense mat of water hyacinth stretching across the lake. The engine strained, but the boat barely moved.
Joseph reached down and picked up a handful of the weed. He studied it, then carried some back to Egerton.
The moment stayed with him. Soon afterwards, the university held a tree-planting day.
Thousands of seedlings went into the ground.
But when the event ended, thousands of plastic seedling bags were left scattered across the campus.
Joseph looked at the bags, then at the hyacinth in his room. What if the bags could be made from the weed? It was only a question. But it refused to go away.
Water hyacinth (Eichhornia crassipes) is among the world's most aggressive invasive species.
It spreads rapidly across nutrient-rich freshwater, forming mats that block sunlight, reduce oxygen and disrupt ecosystems.
At Lake Naivasha, it has become a persistent problem for fishermen and tourism operators.
Samuel Macharia, a fisherman and eco-tourism operator who chairs Central Beach Boat Rides, a 30-member community group, has seen the impact firsthand.
“The hyacinth has been a big challenge to us fishermen, and to those of us doing the eco-tourism business,” he says.
“It blocks our paths and we cannot access the lake. Sometimes the nets are covered by the hyacinth, and you can lose the nets and even the fish.”
For Joseph, the problem became an opportunity to experiment. At Egerton, he began testing what the weed could become.
His first products were crude tumblers and straws but they showed that something useful might be possible. Then his life took an unexpected turn.
Joseph's team won the L'Oréal Brandstorm Innovation competition, earning a competitive internship with local brands at one of the world's largest consumer goods companies.
It was the kind of opportunity many graduates would not walk away from. Joseph did.
As interest in his hyacinth experiments grew, he left L'Oréal and returned to Egerton, deferring his graduation to pursue the idea.
He had no factory, no capital and no blueprint for turning an invasive weed into biodegradable packaging.
“We had to keep iterating until we got it right,” he says.
He eventually completed his BSc in Civil and Environmental Engineering in 2023. By then, HyaPak was taking shape.
Today, the Nairobi-based startup processes water hyacinth into materials used for seedling bags, packaging and carton linings.
Bundles of sun-dried hyacinth arrive from Lake Naivasha, where community members harvest, transport and dry the weed before it is processed.
For Samuel's group, the work has created an additional source of income.
Two boats and four fishermen harvest the hyacinth at a time, then take it to shore for drying.
“The biggest challenge is transporting the hyacinth to the drying spot, and finding a place to dry it,” Samuel says. “Someone has to keep watch until it dries.” Once dried, the material is packed into 90-kilogramme bags and supplied to HyaPak according to demand.
The model is deceptively simple: a weed that once blocked fishermen from reaching the lake becomes raw material that generates income.
But Joseph is careful about what the model has achieved. “We are managing the problem,” he says. “Not solving it.” That restraint is notable in a startup ecosystem where ambitious claims are common.
HyaPak currently employs six permanent staff, while the harvesting partnership provides supplementary income for the community group.
Samuel hopes the company expands its collection so more people can benefit.
He also wants greater government involvement in clearing the lake.
Joseph's work has nevertheless attracted international attention. In 2025, he received the United Nations Environment Programme's Young Champion of the Earth award.
He has also been recognised by the Obama Foundation and received the Prototypes for Humanity Award at COP28 in Dubai.
The recognition has opened doors, but funding remains a challenge.
“Most of the funding is from outside,” Joseph says. “In Kenya, people are yet to recognise our work.”
For him, the bigger issue is not simply money but the systems available to help local innovations move from idea to scale.
One of HyaPak's products could offer a particularly powerful test: its biodegradable tree seedling bag.
Kenya has committed to planting billions of trees, and every seedling needs a bag.
Most are made from plastic and are discarded after planting. HyaPak's alternatives are designed to decompose in the soil as the tree grows. The logic is circular: replace a plastic product with one made from an invasive plant, then allow it to return nutrients to the soil.
If adopted at scale, Joseph believes the environmental impact could be significant. The government could potentially become one of HyaPak's largest customers. The policy ambition exists. The product exists. What remains is connecting the two.
Joseph did not set out to build a global environmental solution. He got stuck in a boat. He noticed plastic bags after a tree-planting exercise. He asked a question and followed it.
His philosophy is now summed up in the sentence that has guided the journey: “Waste is a human concept. Nature has no waste.” He wants HyaPak to expand across continents, becoming part of supply chains and community systems that can survive without him.
“Generations will survive without us,” he says. “That is how I want to leave my footprint in the world.” From a stranded boat to a startup turning an invasive weed into a resource, the idea remains simple: what humans call waste may only be a material waiting for a different purpose.
