What is the poorest reference point for measuring ties to a buried valve?

The poorest reference point for measuring ties to a buried valve is a tree. Trees can be problematic as reference points for several reasons. First, their placement can change over time due to factors like growth or removal, leading to inaccuracies. Additionally, trees have an irregular shape and can vary in height or type, which complicates measuring and referencing.

In contrast, options like a nearby fence post, a manhole cover, or an adjacent building are generally more stable and fixed points. These structures provide reliable reference locations that remain unchanged over time, making them much better for precise navigation and measurement tasks related to buried infrastructure. The immobility and predictability of constructed features compared to natural features like trees underscore why the latter is considered a poor choice for accurate measurement.