Selecting a source for urban water supply Which of the following factors must be evaluated while selecting a city’s water source and its conveyance route?
-
AQuantity and quality of the available raw water
-
BElevation (head) of the source relative to the city
-
CIntervening terrain and right-of-way constraints
-
DAll the above
-
ENone of these
Answer
Correct Answer: All the above
Explanation
Introduction / Context:Source selection drives capital and operating costs for decades. The hydrology, topography, and raw-water characteristics govern treatment needs, pumping energy, and resilience.
Given Data / Assumptions:
- City-scale potable supply.
- Multiple potential sources (river, lake, groundwater, regional scheme).
Concept / Approach:Quantity determines reliability during drought; quality dictates treatment train and operating cost; elevation affects gravity advantage versus pumping; terrain affects alignment feasibility, tunneling, and environmental impacts.
Step-by-Step Solution:Assess safe yield and seasonal variability (quantity).Analyze raw-water contaminants and treatability (quality).Compare available hydraulic head for gravity conveyance (elevation).Survey terrain for constructability, risk, and maintenance access (route).
Verification / Alternative check:Feasibility studies explicitly balance these criteria in multi-objective analysis.
Why Other Options Are Wrong:
- Any single factor alone is insufficient; a complete evaluation requires all listed factors.
Common Pitfalls:Underestimating quality variability (algal blooms, turbidity spikes); neglecting headloss and future expansion corridors.
Final Answer:All the above