Knowledge of water

This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

Medieval depiction of a water mill

The knowledge of water was a late medieval tax (recognition fee, concession fee ) levied by the sovereign for the use of water power from streams and rivers . The owners of water mills and water-powered hammer mills and grinding cabins were liable to pay the fee . With the help of preserved land registers , property holdings, the existence of former cottages and information about the taxpayer are researched.