Let your water source, quantity and quality dictate what you plant. Fruit and nut crops are perennial crops demanding water for the current crop, as well as crops in future years. Plan orchards where a long term reliable water source is available. Vegetables are annual crops, requiring large amounts of water to establish the crop and carry it to maturity. Crop selection also should be based on the reliability and the volume of water available.
High water demanding crops are broccoli, peppers, potatoes and tomatoes.
Crops less critical of exacting water delivery include greens, lettuce, spinach, cantaloupes and squash. The midbed trench has been used successfully in many areas to improve the emergence and stand establishment of fragile seedlings like peppers and tomatoes. So land preparation can also affect how efficiently our plants harvest and use water. Finally, if land is not limiting then one could move to extremely wide spacings on dryland plantings. This allows the potential crop to exploit a very large volume of soil in order to secure its water.