HOW WATER CONSERVATION PRACTICES CAN LEAD TO INCREASED GROUNDWATER PUMPING

Water conservation practices have become very important tools for water managers. The broad category of water conservation may include water efficiency, wise-water use, curtailment of use, graywater reuse, water recycling, rainwater harvesting, or wastewater reclamation and reuse. Some of these “newer” conservation practices are a way to augment water supplies after the application of traditional conservation measures. We developed generic groundwater models to understand the impacts of different conservation measures on groundwater budgets and determined the impacts of conservation measures on a calibrated groundwater flow model of a specific aquifer. Results indicated that water conservation practices may slightly increase annual recharge rates, thus helping to maintain natural discharge from an aquifer. In addition, changes in the location of groundwater recharge through implementation of conservation practices can cause changes in groundwater flow directions. Because artificial recharge sites are commonly associated with sites of urban development and contamination, taking these measures into account in groundwater modeling is an important component of water resource management. If a water management scheme is optimized to provide maximum pumping rates as a percentage of recharge (such as safe yield), using waste-water treatment plant effluent as irrigation causes less groundwater pumping to occur. This is because as more effluent is used to recharge the aquifer, more groundwater can be pumped. However, discharging effluent directly to the environment causes more dramatic shifts in regional groundwater flow patterns than distributing effluent across a larger irrigated area. These shifts become more complex in management scenarios that demand seasonal variation in discharge volumes.