A shared raised platform for seed and grain before the flood

On the chars of Kurigram floods spoil grain and seed kept on mud floors, and next season people borrow seed again. Several village families can build a shared raised platform or store on high ground. Before the rains each dries their seed and grain, bags it with a name and stores it there. Two people hold the key by rota. You need bamboo, tin, polythene, a bit of high land and a trusted keeper.