Slightly less than _______ of the freshwater is stored as groundwater in the world's aquifers.

30% is correct answer.

Key Points

•  70% of freshwater is stored as ice sheets and glaciers in Antarctica, Greenland, and mountainous regions of the planet, whereas less than 30% is stored as groundwater in the world's aquifers and less than 1% as surface water in rivers, lakes, and so on.
• Only about 3% of the water on Earth is fresh water. Only around 1.2 percent of that can be used as drinking water; the rest is trapped in glaciers, ice caps, and permafrost, or is buried far below.
• The distribution of water on Earth
• The percentage of ocean water is 97.2 percent.
• 2.15 percent glaciers and other ice
• Groundwater (0.61%).
• Lakes with fresh water: 0.009%
• Internal seas: 0.008 percent
• 0.005 percent moisture in the soil
• 0.001 percent of the atmosphere
• 0.0001% for rivers.

Additional Information

• The Earth is known as the "Blue Planet" because water covers 71 percent of its surface.
• Water can also be found beneath the earth's surface and as water vapor in the atmosphere. Water is a scarce resource. The bottled water we drink today could be the same water that once dripped down the back of a woolly mammoth.
• Because the Earth is a closed system, very little substance, including water, ever escapes or enters the atmosphere; the water that existed billions of years ago is still there today.
• The hydrologic cycle, on the other hand, cleans and restores the Earth's water supply.