The total required storage capacity of a distribution reservoir is typically determined by considering which of the following combinations?
- ABalancing storage + Fire storage + Breakdown storageCorrect
- BDead storage + Balancing storage + Emergency storage
- CMaximum daily demand + Minimum hourly demand
- DAverage daily demand + Fire storage
Solution
Concept
Storage capacity components of distribution reservoir
Formula
Total Storage = Balancing Storage + Fire Storage + Breakdown Storage
Step-by-step solution
1. Municipal distribution reservoirs perform three operational functions. 2. Balancing storage compensates for diurnal demand fluctuations against steady pumping. 3. Fire storage provides a reserved volume for emergency firefighting demand. 4. Breakdown storage ensures water supply during pump or pipeline maintenance. Answer: A
Explanation
The total storage capacity of a municipal distribution reservoir comprises three functional reserves: balancing (equalizing) storage to accommodate hourly demand fluctuations against constant pumping, fire storage to meet statutory emergency firefighting flow requirements, and breakdown storage to maintain supply during mechanical or electrical failures.
Why the other options are wrong
B) Dead storage applies to dam reservoirs below sluice inverts, not distribution reservoirs. C) Demand figures are flow rates, not volumetric storage components. D) Excludes breakdown storage required for pump failure contingencies.
Shortcut
Distribution reservoir storage = Balancing + Fire + Breakdown (emergency).
Common mistake
Confusing distribution reservoirs with raw water dams (which require dead storage).
Correct answer: A) Balancing storage + Fire storage + Breakdown storage