One of the most ingenious traditional irrigation methods is the system of Kuhls found in the hilly regions of Himachal Pradesh. A Kuhl is a diversion channel that taps water from a glacier or stream and carries it over long distances to irrigate fields in downstream villages. The system is managed by the community. A temporary headwall, often made of river boulders, is built across a stream to divert water into the channel. The community collectively maintains the Kuhl, clearing silt and repairing damages. This system is a remarkable example of community-managed, gravity-based irrigation that has sustained agriculture in mountainous terrain for centuries.