What is the imaginary line drawn through the middle of a stream called?

The correct term for the imaginary line drawn through the middle of a stream is known as the "thread." This line represents the deepest part of the stream channel and is significant in various hydrological and legal contexts. The concept of the thread is essential in surveying, particularly in establishing property boundaries along waterways where the flow of water may dictate ownership or rights. The middle of the stream, or thread, is often used as a reference point for navigability and the flow of water rights.

Understanding the definition and relevance of the thread helps in comprehending how waterways are managed and how boundaries are defined in relation to bodies of water. It is important for surveyors to recognize the significance of this line when determining property lines, especially in areas where land ownership is affected by the presence of a stream or river.