A farmers' team to keep the irrigation channel clear by rota

In Bogura fields weeds and silt build up in the irrigation channel and water never reaches the far end. Farmers at the tail are always left out. All farmers along the channel can form a team. Before the dry season they clear it together in one day. Later one person checks it each month by rota. Agree and write down the water-sharing rule together. You need spades, baskets, every farmer's consent and a simple rules sheet.