India, Feb. 18 -- Sand mining has expanded rapidly across Kenyan counties amid urban growth and infrastructure projects.

The UN has flagged Kenya for unsustainable sand harvesting practices.

Most profits are made in urban markets, though local loaders and cooperatives rely on the trade.

Weak enforcement, bribery and land disputes complicate regulation.

Researchers argue that integrating informal governance structures into formal policy could improve equity and sustainability.

The sun is rising in Kenya's Kajiado county, just outside Nairobi, and a truck is rumbling over dusty ground towards a riverbank. Young men guide the driver to a parking spot and then spring into action, each with a scoop, filling the truck from a heap of the mo...