Concept:A farmstead is sited near water for beneficial farming needs, not for harmful effects like erosion.
Explanation:Being close to a water source helps reduce the cost of water supply.
It also supports an efficient irrigation system on the farm.
Water is needed for processing farm produce such as washing and cleaning.
However, erosion of farm structures is a possible risk of building near water, not a reason for doing so.
Therefore, erosion of farm structures is the exception.
Answer:D. erosion of farm structures