---
title: "Planning stages and field investigations"
subject: "Hydropower Engineering"
chapter: 2
key: "semester_7/hydropower_engineering:planning-stages-field-investigations"
source: https://www.bctengineer.com/q/semester_7/hydropower_engineering/planning-stages-field-investigations
site: BCT Engineering
---

# Planning stages and field investigations

Hydropower Engineering · Chapter 2: Planning of Hydropower Projects

- Asked in: 2074 Ashwin, 2+6 marks
- Video: [Chpt2 Planning and Investigation of Hydropower Projects-Hydropower Engineering #dipakdahal](https://www.youtube.com/watch?v=TwVC4X_pEWE) — 𝐄𝐫. 𝐃𝐢𝐩𝐚𝐤 𝐃𝐚𝐡𝐚𝐥
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/hydropower_engineering/planning-stages-field-investigations
- Whole chapter: https://www.bctengineer.com/md/semester_7/hydropower_engineering/chapter-2

## Question

What are the various stages of hydropower planning? If you have been appointed as a water resources engineer in the Water Resources Ministry and you are assigned to undertake various investigations related to water resources, discuss the field investigations you carry out at various stages of the hydropower project.

## Short answer

Hydropower planning stages are reconnaissance, pre-feasibility, feasibility, and detailed design. Field investigations range from site visits, spot discharge, and regional hydrology at reconnaissance; topographic survey, gauging, and surface geology at pre-feasibility; detailed survey, drilling, and EIA at feasibility; to precise foundation surveys and model tests at detailed design.

## Answer

#### Stages of hydropower planning
1. Reconnaissance (identification)
2. Pre-feasibility
3. Feasibility
4. Detailed engineering design and tender

#### Field investigations at each stage
**Reconnaissance**
- Site visit for access, river and valley form, rough geology.
- Spot discharge measurement; use of regional hydrology; collecting maps.
- Identify environmental and social constraints.

**Pre-feasibility**
- Topographic survey of key areas; river cross-sections.
- Hydrology: install a gauge, measure flows, estimate FDC, floods and sediment.
- Geology: surface mapping, geophysics and a few boreholes.
- Survey of access road and transmission line corridors; preliminary IEE scoping.

**Feasibility**
- Detailed topographic survey (1:1000 or larger) at all structure sites.
- Hydrology: at least one year of gauging, sediment sampling, flood and low-flow analysis.
- Geology/geotechnics: drilling at weir, intake, desander, tunnel portals, penstock and powerhouse; test adits; laboratory and in-situ rock/soil tests; material surveys.
- Socio-environmental baseline survey and IEE/EIA field work, land and settlement survey.

**Detailed design**
- Very detailed survey and extra drilling and tests of the exact foundation of structures.
- Hydraulic model tests (spillway, intake, desander).
- Final hydrological check, and survey for construction camps, roads and transmission line.
- Environmental monitoring programme set-up.

## Check yourself

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

1. Which field work is typical at reconnaissance stage?
   A. Site visit, spot discharge measurement and regional hydrology use
   B. Hydraulic model tests
   C. Test adits and laboratory tests
   D. Tender preparation
   Answer: A. Reconnaissance is a light screening with site visits and spot measurements. (Key point: Reconnaissance investigations)

2. What hydrological field work is done at feasibility stage?
   A. Spot measurement only once
   B. At least one year of gauging, sediment sampling, flood and low-flow analysis
   C. No gauging
   D. Only desk study
   Answer: B. A full year of gauging captures seasonal variation. (Key point: Feasibility hydrology)

3. Where is drilling carried out at feasibility stage?
   A. Only at the powerhouse
   B. Nowhere
   C. At weir, intake, desander, tunnel portals, penstock and powerhouse
   D. Only in the reservoir
   Answer: C. Drilling is done at all main structure locations. (Key point: Feasibility geotechnics)

4. Which activity is specific to the detailed design stage?
   A. Selecting sites
   B. Hydraulic model tests for spillway, intake and desander
   C. Spot discharge
   D. Scoping of environment only
   Answer: B. Model testing confirms structure hydraulics before final design. (Key point: Detailed design investigations)

## Related in Hydropower Engineering

- [Study stages for 10 MW remote project](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Asmall-10mw-study-stages) — Hydropower Engineering, chapter 2
- [Stages of hydropower development cycle](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Adev-cycle-stages) — Hydropower Engineering, chapter 2
- [300 MW reservoir project: planning to commissioning](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Areservoir-300mw-planning-to-commissioning) — Hydropower Engineering, chapter 2
- [Pre-feasibility site-specific investigations](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Aprefeasibility-site-investigations) — Hydropower Engineering, chapter 2
- [Pre-feasibility vs feasibility; site investigations](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Aprefeasibility-vs-feasibility-investigations) — Hydropower Engineering, chapter 2
- [Surge and water hammer: 25 m³/s, 15 m surge tank](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Asurge-numerical-25cumec-2-penstocks-15m-tank) — Hydropower Engineering, chapter 6, asked 3×

## Related in other subjects

- [Stages of hydropower project study](https://www.bctengineer.com/question.md?key=semester_6%2Fhydro_power%3Ahydropower-study-stages) — Hydro Power, chapter 3, asked 3×
- [Quartz significance for hydropower project](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Aquartz-hydropower-significance) — Engineering Geology II, chapter 1
- [Stages of planning irrigation projects](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Aplanning-stages-irrigation-projects) — Irrigation and Drainage Engineering, chapter 1, asked 3×
- [Define hydrology and its importance in water resources](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Ahydrology-define-importance) — Engineering Hydrology, chapter 1