01 AR - Wet Season1
When there is a surplus of water, can we bank it underground for later?
What you’re watching An aquifer storage and recovery (ASR) well injecting treated fresh water through a confining layer into a confined aquifer during the wet season; a freshwater ‘bubble’ grows around the well as injection continues.
The mechanism Managed aquifer recharge stores surplus water by injecting it into an aquifer, where it forms an expanding bubble of fresh water around the well. The aquifer becomes a reservoir — no evaporation, no land taken — holding the water until it is needed.
Why it matters Water is unevenly distributed in time and space — too much in the wet season or in one region, too little in the dry season or in another. Banking the surplus underground is one of the most promising ways to balance that mismatch.
IGW-NET Watching the freshwater bubble expand as injection proceeds turns an invisible underground store into something you can see, size, and plan around — IGW-NET quantifying the bubble dynamics directly.
02 AR - Dry Season1
When the dry season comes, how much of the banked water can we actually get back?
What you’re watching The same ASR well in the dry season, now pumping the stored water back out for irrigation and supply; the freshwater bubble shrinks as water is withdrawn.
The mechanism During recovery the well reverses: it extracts the stored water and the bubble contracts. The fraction you can recover at usable quality — the recovery efficiency — is the key performance measure, and it depends on how much the stored water has moved or mixed since injection.
Why it matters Storage is only useful if you can get the water back when and where you need it. Drift, dispersion, and mixing during storage all reduce recovery efficiency — the difference between a working water bank and a loss.
IGW-NET Watching the bubble shrink during recovery, and tracking how much returns, makes recovery efficiency a quantity you can measure and optimize rather than guess.
03 AR - Wet Season2
What if the aquifer you are injecting into is brackish or saline?
What you’re watching A second injection cycle, now emphasizing that the freshwater bubble is being pushed into ambient brackish water; the bubble displaces the salty water outward, with a mixing zone at its edge.
The mechanism Often the target aquifer holds brackish or saline water — fresh water is injected into impaired water. The freshwater bubble displaces the saltier water, and a transition (mixing) zone forms at the interface. The injected fresh water is good quality; the ambient water is not.
Why it matters This is the common and tricky case: you must recover your stored fresh water before it drifts or mixes into the surrounding brackish water, or you will pull up water of inferior quality — defeating the purpose.
IGW-NET Visualizing the freshwater bubble inside brackish water, and the mixing zone at its edge, shows exactly where good water ends and impaired water begins — the information recovery decisions depend on.
04 AR - Dry Season2
Does storing in a brackish aquifer get easier with repeated cycles?
What you’re watching Recovery in the second dry-season cycle; with a freshwater buffer left behind from earlier cycles, more of the injected water returns at usable quality than in the first cycle.
The mechanism Over repeated store-and-recover cycles, residual fresh water builds a buffer that holds the brackish water back, so each cycle’s recovery efficiency tends to improve. The aquifer is gradually ‘conditioned’ into a more reliable freshwater store.
Why it matters It changes how you operate a water bank: early cycles may recover poorly, but persistence builds a buffer that makes the store progressively more dependable — a counterintuitive but crucial operational insight.
IGW-NET Running cycle after cycle and watching the recoverable bubble grow more robust quantifies how a brackish aquifer is conditioned into a working freshwater reservoir — a multi-cycle experiment impossible to run in the field on a planning timescale.