Water: A Precious Resource

• Understand the importance of water and the sources of freshwater.
• Understand the water table and how it is affected by rainfall and usage.
• Recognise causes of water scarcity and ways to conserve water (e.g. rainwater harvesting).

1. Only about 2.7% of Earth's water is fresh, and much of that is locked in glaciers/ice caps.
2. The water table is the upper level of underground water; it varies with rainfall, usage, and geography.
3. Over-extraction of groundwater (for irrigation, industry) lowers the water table faster than it can be replenished.
4. Rainwater harvesting collects and stores rainwater for later use, helping recharge the water table.
5. Water scarcity results from a growing population, wasteful use, pollution, and reduced rainfall/forest cover.

Why does excessive groundwater pumping in a region lower its water table over time?

Groundwater is pumped out faster than rain can seep down and refill (recharge)
it, so the water level underground gradually drops.

• Assuming freshwater is unlimited — it is a limited and unevenly distributed resource.
• Confusing "water table" with a literal physical table — it's an underground water level.
• Believing rainwater harvesting is only useful in villages — it helps cities too.

• What percentage of Earth's water is fresh and readily available?
• Name one method to conserve water.

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