Long-Term Effects of Irrigation with Imported Water on Water Levels and WaterQuality

摘要

A variety of water problems have resulted, both directly and indirectly, from theincrease in irrigation. The use of imported irrigation water has been linked to significant rises in ground-water levels in many areas. These rises are the result of percolation of water applied to crops and seepage from the distribution system. The report describes the changes in ground-water levels and budgets from pre-development to present day. The report also presents the present-day distribution of nitrate concentration in ground water and discusses the possible sources of the nitrate. A section on geohydrologic factors related to management of the area's water resources summarizes the key aspects of the report for water managers.