Reservoir capacity components – the term “silt storage” corresponds to which storage category? In reservoir planning, the volume intentionally reserved to accommodate sediment (silt) deposition over the project life is equivalent to:

Introduction / Context:Reservoir capacity is partitioned into functional zones. Designers assign a portion that can be lost to sedimentation over the project life; understanding where this “silt storage” comes from is key to sustainable yield.

Given Data / Assumptions:

• Sediment accumulates at the bottom and progressively encroaches on lower elevations of storage.
• Dead (inactive) storage lies below the minimum operating level.

Concept / Approach:Because sedimentation begins at the lowest pool levels, the capacity primarily sacrificed is the dead storage. Designers may augment dead storage to accommodate forecast sediment so that live storage (usable for regulation and supply) remains largely intact during the design life.

Step-by-Step Solution:Identify the locus of sediment deposition → lowest elevations.Match this with the storage category that cannot be released for use → dead storage.

Verification / Alternative check:Operation curves place minimum drawdown level above the dead storage top; sediment surveys track loss primarily within this zone.

Why Other Options Are Wrong:

• Live/effective storage: intended for regulation and should be preserved from long-term siltation as far as practicable.
• Flood control storage: temporary upper-pool space; not a sediment sink by design.

Common Pitfalls:Assuming sedimentation uniformly reduces all zones; in practice, geometry and operation concentrate deposition within dead storage.

Final Answer:Dead storage