SOP: INTAKE & SEDIMENT MANAGEMENT | FRANCIS UNIT 1
SOP-OPS-001 REV 3.1

INTAKE & SEDIMENT MANAGEMENT

REVENUE KILLER: TRASH & DEBRIS

Logic: Every leaf, branch, or plastic bag on the rack creates flow resistance.

Impact: Power Loss

Head Loss = Lost Power. A 1-meter drop due to a blocked rack is pure financial loss.

Intake Integrity

A clean intake is the first line of defense. If trash passes the rack, it destroys MIV seals and blocks guide vanes.

CLEANING TRIGGER

The intake rack is the lungs of the hydro system. It must breathe freely.

Monitoring System

Differential Pressure (dP) Analysis

Action Threshold
> 20 cm

Initiate Cleaning

Methodology

Automatic / Manual Raking

SEDIMENT THREAT & FLUSHING

Synergistic Threat Logic

Surface Abrasion

Sand strips the oxide layer off the runner/guide vanes.

Cavitation Accelerator

Provides a rough surface for bubble formation.

Flushing Procedure

  • 01 Check silt level weekly (daily during high water).
  • 02 Open bottom outlets to flush accumulated sediment back to river.
  • 03 Ensure flushing tunnel is clear and flow returns only when water is clear.

OPERATOR MISSION TASKS

DAILY

Check Rack Differential. Clean if > 20cm.

WEEKLY

Flush Settling Basin (Sand Trap).

STORM EVENT

Emergency Rack Inspect due to heavy debris.