---
title: "Layout of hydropower scheme components"
subject: "Hydro Power"
chapter: 5
key: "semester_6/hydro_power:hydropower-scheme-layout"
source: https://www.bctengineer.com/q/semester_6/hydro_power/hydropower-scheme-layout
site: BCT Engineering
---

# Layout of hydropower scheme components

Hydro Power · Chapter 5: Components of Hydropower System

- Asked in: 2072 Asoj, 3 marks
- Video: [Hydro power plant, Parts of Hydro plant, Components of Hydro plant #HydroPlant #PowerPlant](https://www.youtube.com/watch?v=3ixtdPORwsw) — Mechanical Engineering Management
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/hydro_power/hydropower-scheme-layout
- Whole chapter: https://www.bctengineer.com/md/semester_6/hydro_power/chapter-5

## Question

Sketch the layout of hydropower scheme showing different components parts.

## Short answer

A hydropower scheme diverts water at a weir, passes through intake, gravel trap, and settling basin, then flows via headrace to a forebay or surge tank. A penstock feeds the powerhouse turbine; water returns through a tailrace. Key components include diversion, conveyance, pressure pipe, powerhouse, and tailrace.

## Answer

A typical **run-of-river hydropower scheme** diverts water from a river, carries it along a gentle slope to gain head, drops it through a penstock to the turbines, and returns it to the river.

```text
 river
  |~~~|  diversion weir
  |===|--> intake --> gravel trap
  |~~~|               |
  |   |               v
  |   |          settling basin (desander)
  |   |               |
  |   |               v
  |   |     headrace canal / tunnel
  |   |               |
  |   |               v
  |   |     forebay / surge tank
  |   |               |
  |   |            penstock
  |   |               |
  |   |               v
  |   |<-- tailrace <-- POWERHOUSE --> switchyard
  |~~~|                     (turbine + generator)
```

#### Components
1. **Diversion weir/dam:** raises water level and diverts flow.
2. **Intake:** draws design flow, with trash rack and gate.
3. **Gravel trap and settling basin:** remove gravel and fine sand.
4. **Headrace canal or tunnel:** carries water at gentle slope.
5. **Forebay (canal) or surge tank (tunnel):** handles load changes.
6. **Penstock:** pressure pipe to the turbine.
7. **Powerhouse:** turbines, generators, controls.
8. **Tailrace:** returns water to the river.
9. **Switchyard and transmission line:** deliver power to the grid.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which is the correct flow order in a run-of-river scheme?
   A. Weir/intake, gravel trap, settling basin, headrace, forebay, penstock, powerhouse, tailrace
   B. Tailrace, forebay, intake
   C. Penstock, intake, weir, powerhouse
   D. Powerhouse, headrace, weir
   Answer: A. Water is diverted, cleaned of sediment, conveyed, dropped through the penstock and returned via tailrace. (Key point: Order of components)

2. Which is used at the end of a headrace tunnel?
   A. Gravel trap
   B. Forebay
   C. Surge tank
   D. Weir
   Answer: C. Forebay is for canals; surge tank for tunnels. (Key point: Forebay or surge tank)

3. What do the gravel trap and settling basin remove?
   A. Gravel and fine sand
   B. Floating logs only
   C. Dissolved air
   D. Heat
   Answer: A. They protect the waterway and turbines from sediment. (Key point: Gravel trap and settling basin)

4. The tailrace:
   A. Diverts water at the weir
   B. Raises head
   C. Returns the water to the river after the turbine
   D. Stores sediment
   Answer: C. It carries turbine discharge back to the river. (Key point: Tailrace)

## Related in Hydro Power

- [Functions and layout of forebay](https://www.bctengineer.com/question.md?key=semester_6%2Fhydro_power%3Aforebay-functions-layout) — Hydro Power, chapter 5, asked 2×

## Related in other subjects

- [Micro hydro scheme components and classification](https://www.bctengineer.com/question.md?key=semester_6%2Fenergy_resources%3Amicro-hydro-scheme-components-classification) — Energy Resources, chapter 5
- [Components and layout of diversion headworks](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Aheadworks-components-layout) — Irrigation and Drainage Engineering, chapter 5, asked 2×
- [Hydropower plant components and functions](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Ahydropower-components-functions) — Power Plant Design, chapter 3, asked 2×
- [Hydropower requirements and components](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Ahydropower-requirements-components) — Energy Environment and Society, chapter 3