During times of water abundance, surpluses can be withdrawn from a river (or other source) and then injected and stored within an aquifer. When the original water source runs low due to drought, low rainfall or other causes, this water can then be pulled from the aquifer and used at the surface. Some Artificial Storage and Recover (ASR) facilities inject treated wastewater rather than surface water into an aquifer, while other facilities inject groundwater from a different aquifer.

A. Watch the simulation videos on artificial recharge under library: education video at www.magnet4water.com and answer the following questions:

• where is the artificially recharged water stored in the aquifer?
• why is that ASR is often less effective hydrologically in a confined aquifer than in an unconfined or leaky confined aquifer?
• under what conditions ASR works best?
• what are the pros and cons of ASR?

B. Develop a 3D MAGNET model that reproduces the ASR processes in the animations above and perform a sensitivity analysis of the performance of ASR with respect to the hydraulic conductivity of the confining layer.

Write a 1-2 page memo that summarize results, comparing the effectiveness of ASR for different types of aquifers based on your numerical experimentation.

• Use ‘Synthetic mode’ in MAGNET to create a model domain with the same dimensions as shown in the map
• Overlay the provided SiteMap image file included in the problem description. Choose ‘Use Domain Extent’ to fit the image to the established domain size.
• Conceptualize the model as 1-layer confined aquifer system. Conceptualize the lakes as a constant head zone features.
• The lateral and bottom boundaries can be treated the domain boundaries as ‘no-flow’ boundaries.