Idaho Code § 55-309: Right to lateral and subjacent support.

Each coterminous owner is entitled to the lateral and subjacent support which his land receives from the adjacent land, subject to the right of the owner of the adjoining land to make proper and usual excavations on the same for purposes of construction, on using ordinary care and skill, and taking reasonable precautions to sustain the land of the other, and giving previous reasonable notice to the other of his intention to make such excavation.