Surface Water:

• Consists of natural water found on the Earth's surface, such as rivers, lakes, and reservoirs

• More susceptible to contamination due to pollutants from urban runoff, industrial discharges, and agricultural runoff

• Often requires extensive treatment before it can be used for drinking water

• Is heavily impacted by climate change and time of the year, leading to variability in water availability

Ground Water:

• Found in the saturated zone of soil and rocks, where the spaces are filled with water, accessed through wells or springs

• Over-extraction can lead to depletion of water tables, land subsidence, and reduced water quality

• Less susceptible to pollution than surface water, but can still be contaminated by leachates

• Recharge of groundwater can be very slow, making it a non-renewable

• Legal issues can arise over rights to access and extract groundwater, especially in regions where it crosses property lines or borders

Rainwater:

• Rainwater harvesting captures and stores rain, usually from rooftops, providing a clean water source in areas with adequate rainfall, but requires storage due to supply variability

• The system consists of catchments, gutters, and tanks, needing regular maintenance to prevent contamination and ensure long-term functionality

• Challenges include the need for significant initial investment and the suitability of the method to regions with consistent and sufficient rainfall

Aquifer:

• Aquifers are underground layers of water-bearing permeable rock, sand, or gravel that can provide water for wells and springs

• The sustainability of aquifers is at risk due to variable natural recharge rates and overuse, which can result in depletion

• Excessive pumping may introduce contaminants such as radon, arsenic, and man-made pollutants into aquifers degrading freshwater resources

• Governments have implemented laws to ensure balanced pumping and recharge