The most important purpose of irrigation was to

preserve scarce water supplies.

provide transportation routes.

share water with neighboring peoples.

keep farmers from growing food surpluses.

The best answer is preserve scarce water supplies.

The objective of irrigation is associated with higher productivity, higher profitability, better product quality, and production stability. The use of irrigation is a technical option of water application that aimed mainly at the fight against drought and thus preserves the sources of water in the scarce region.

Conservation means both development and protection.This generation may use resources today, but they may not ruin things for the next generation.We are poor stewards if we ruin the land and leave it worthless for our children.We are good stewards if we leave the land better than we found it.