---
title: "Hydropower site selection factors"
subject: "Power Plant Design"
chapter: 3
key: "semester_8/power_plant_design:site-selection-discharge-factors"
source: https://www.bctengineer.com/q/semester_8/power_plant_design/site-selection-discharge-factors
site: BCT Engineering
---

# Hydropower site selection factors

Power Plant Design · Chapter 3: Hydro Power Plant Design

- Asked in: 2078 Chaitra, 4+2 marks
- Video: [Site selection of hydro power plant|Factors for selection of Hydro plant|Site selection factors|GTU](https://www.youtube.com/watch?v=lyTzlHhLmVs) — Mechanical Engineering Management
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_8/power_plant_design/site-selection-discharge-factors
- Whole chapter: https://www.bctengineer.com/md/semester_8/power_plant_design/chapter-3

## Question

What are the factors to be considered during selection of appropriate site for hydropower? Also mentions the factors that govern discharge of a hydropower project.

## Short answer

Hydropower site selection factors: water availability, sufficient head, sound geology, storage possibility, low sediment load, good access, short grid distance, minimal environmental/social impact, low hazard risk, favorable cost. Discharge factors: catchment area, rainfall plus snow/glacier melt, evapotranspiration losses, catchment characteristics, and upstream abstractions.

## Answer

#### Factors for selection of a hydropower site
1. **Availability of water:** a river with good, reliable flow (from rainfall, snow and glaciers), shown by long-term hydrological data.
2. **Available head:** a steep river reach or a river bend where a short tunnel gives a large head.
3. **Geology:** sound rock for dam, tunnel and powerhouse; avoid active faults, landslides and weak zones.
4. **Storage possibility:** a narrow gorge with a wide valley upstream if storage is wanted.
5. **Sediment load:** low sediment or space for a desander.
6. **Access and transport:** roads for heavy equipment and construction materials.
7. **Distance to load or grid:** short transmission line reduces cost and losses.
8. **Environmental and social impact:** minimal submergence, resettlement, forest loss and impact on protected areas.
9. **Natural hazards:** floods, GLOF, earthquakes, debris flows.
10. **Cost of the project:** cost per kW and per kWh.

#### Factors governing discharge of a hydropower project
1. **Catchment area** above the intake.
2. **Rainfall** amount and distribution (monsoon), plus **snow and glacier melt**.
3. **Evaporation and transpiration** losses.
4. **Catchment characteristics:** slope, soil, geology, forest cover, which control runoff and baseflow.
5. **Upstream use:** irrigation and drinking water abstractions, and riparian release requirement.

## Check yourself

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

1. Why is geology important in site selection?
   A. It sets the river colour
   B. Sound rock is needed for dam, tunnel and powerhouse, avoiding faults and landslides
   C. It decides the tariff
   D. It determines rainfall
   Answer: B. Stable, sound rock reduces cost and risk for the dam, tunnel and powerhouse. (Key point: Head and geology)

2. A short distance to the load or grid is preferred because it:
   A. Increases head
   B. Increases rainfall
   C. Reduces transmission cost and losses
   D. Removes need for sediment control
   Answer: C. A shorter line costs less and has lower losses. (Key point: Transmission distance)

3. Which set governs the discharge of a hydropower project?
   A. Road access, geology and tariff
   B. Catchment area, rainfall and snow/glacier melt, evaporation, catchment characteristics, upstream use
   C. Generator speed and number of poles
   D. Transformer impedance and BIL
   Answer: B. River discharge depends on hydrological and catchment factors and upstream abstraction. (Key point: Factors governing discharge)

4. Forest cover, soil and slope of the catchment mainly affect:
   A. Runoff and baseflow
   B. Generator efficiency
   C. Penstock thickness
   D. Transformer cooling
   Answer: A. Catchment characteristics control how much rainfall becomes runoff and baseflow. (Key point: Catchment characteristics)

## Related in Power Plant Design

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- [Project selection with high sediment rivers](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aproject-selection-sediments) — Power Plant Design, chapter 3
- [High dam hydropower project components](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Ahigh-dam-components) — Power Plant Design, chapter 3
- [Riparian release and design discharge](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Ariparian-design-discharge) — Power Plant Design, chapter 3
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- [Factors in choosing a generator](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Agenerator-selection-factors) — Power Plant Design, chapter 4, asked 3×

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- [Why a canal fall; site selection factors](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Acanal-fall-purpose-site-selection) — Irrigation and Drainage Engineering, chapter 7