Classification of water sources Which of the following is correctly classified as a <em>surface water</em> source for a water-supply project?

Introduction / Context:
Water sources are broadly categorized into surface water and groundwater. Proper classification affects treatment design and yield analysis.

Given Data / Assumptions:

• Surface water is water present on the land surface (rivers, lakes, reservoirs) principally from precipitation and runoff.
• Groundwater is water stored in aquifers and accessed through wells/springs/galleries.

Concept / Approach:
Rainfall is the driver of surface runoff that fills rivers and lakes; thus, the resource captured in reservoirs is surface water. Wells and springs access subsurface flows and are groundwater sources.

Step-by-Step Solution:

Verification / Alternative check:
Design standards treat surface water as more variable in turbidity and pathogen load, requiring full conventional treatment.

Why Other Options Are Wrong:

• (a) and (c) wells draw groundwater.
• (b) springs discharge groundwater at the surface but are classified as groundwater source types.
• (e) infiltration galleries induce riverbank filtration but are groundwater works.

Common Pitfalls:
Confusing the origin point (surface appearance) with classification; springs emerge at the surface but are groundwater-fed.

Final Answer:
Rain (runoff collected in rivers/lakes/reservoirs)