Technical Abstract: Forty percent of freshwater withdrawals in the U.S. are for irrigated agriculture, which contributed 55$ billion to the economy in 2002. Increasing diversions of water for urban, environmental, and other uses will likely decrease water available to agriculture. Agricultural water conservation is touted as a good method for minimizing the impact of such diversions on production. However, there are limitations to true water savings through increasing irrigation efficiency. We focus on four areas: reduction of unnecessary evaporation and transpiration, more effective use of rainfall, reduction of deep percolation water that becomes severely degraded in quality, and reduction of runoff from fields that is not reusable downstream. The wide variety of hydrologic settings makes it difficult to determine true water savings from conservation practices without a thorough analysis. On size does not fit all. On-farm water conservation practices that provide true water savings at one location may be ineffective at another. In large irrigation projects, water delivery limitations often present an obstacle to on-farm water conservation effort. Canal automation is a relatively new technology that promises to remove this water conservation barrier