--- title: "Intake definition, components, river intake" subject: "Water Supply Engineering" chapter: 5 key: "semester_5/water_supply_engineering:intake-components-river" source: https://www.bctengineer.com/q/semester_5/water_supply_engineering/intake-components-river site: BCT Engineering --- # Intake definition, components, river intake Water Supply Engineering · Chapter 5: Intakes - Asked in: 2075 Chaitra, 8 marks; 2081 Bhadra, 6 marks (asked 2 times) - Video: [Types of Intake Structure - Water Supply and Distribution of Water - Environmental Engineering 1](https://www.youtube.com/watch?v=RrtbXAqmyIo) — Ekeeda - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_5/water_supply_engineering/intake-components-river - Whole chapter: https://www.bctengineer.com/md/semester_5/water_supply_engineering/chapter-5 ## Question Define intake. What are the components of an intake? Sketch and explain the general river intake arrangement. ## Short answer An intake draws water from a source to conveyance. Components: intake ports with bell-mouth, coarse and fine screens, intake well/tower, sluice gates/valves, conveying pipe, sump/pump well, footbridge, and protection works. River intake tower has multiple screened ports at different levels for selective withdrawal. ## Answer #### Definition An **intake** is a structure built in or near a water source (river, lake, reservoir, canal or spring) to draw water safely in the required quantity and send it to the conveying main, pump well or treatment plant. #### Components of an intake 1. **Intake opening / port** with a bell-mouth entry, placed at one or more levels. 2. **Coarse screen (trash rack)** with bars 20 to 50 mm apart to stop large floating objects, and a **fine screen** (6 to 12 mm mesh) to stop small debris. 3. **Intake well / tower / chamber** that houses the gates and valves and lets water settle. 4. **Sluice gates / valves** to regulate or cut off flow. 5. **Conveying (intake) pipe or conduit** from the well to the pump house or main. 6. **Sump or pump well** (for pumped schemes) and a **foot bridge** for access. 7. **Protection works**: pitching, groynes, wing walls, embankment, guard rails, and a **flushing / scour pipe** for removing silt. #### General river intake A river intake is a tower or well built in (or at the edge of) the river with openings at different levels. Water enters the openings through screens, passes into the well and then flows by gravity (or is pumped) through the intake pipe to the treatment plant. ```text Foot bridge =========|=========== | Intake tower HFL ~~~~~ | [ ] gate/valve | __|__ upper port NWL ~~~~~ |/ | \ <-- screens | |__ middle port LWL ~~~~~ | | |___|__ lower port River bed ///|\\\ \|/ intake pipe to pump well/treatment ``` **Working** - Ports at two or three levels let the operator draw the clearest water at any river stage: the upper ports when the river is high (the surface water carries less silt), and the lower ports when the river is low. - Coarse and fine screens at the ports stop floating matter, leaves, fish and debris. - Gates or valves on each port regulate flow and isolate a port for repair. - The water travels from the intake well through the intake pipe to the pump well or the plant. - The entrance velocity is kept low (0.15 to 0.3 m/s) so that little silt and debris are drawn in. A foot bridge gives access for operation and cleaning. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is an intake? A. Structure that draws water from a source and sends it to the main or plant B. A valve for distribution C. A tank that stores treated water D. A device that softens water Answer: A. An intake safely draws the required quantity from a river, lake, reservoir, canal or spring. (Key point: Definition) 2. What is the role of coarse and fine screens? A. Both soften water B. Coarse removes silt; fine adds chlorine C. Both remove bacteria D. Coarse stops large floating objects; fine stops small debris Answer: D. Trash racks (20 to 50 mm) stop large objects; fine screens (6 to 12 mm) stop small debris. (Key point: Screens) 3. What is the flushing/scour pipe for? A. Venting air B. Removing silt C. Measuring flow D. Supplying water Answer: B. It is among the protection works used to remove silt. (Key point: Flushing pipe) 4. Why use multiple ports? A. Reduce screens B. Draw clearest water at any river stage C. Cut cost D. Raise the water level Answer: B. Different river stages carry different silt, so level choice matters. (Key point: Port levels) ## Related in Water Supply Engineering - [General river intake and site selection](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ageneral-river-intake) — Water Supply Engineering, chapter 5, asked 3× - [Dry river intake with sketch](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Adry-river-intake) — Water Supply Engineering, chapter 5, asked 2× - [Wet and dry river intake](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Awet-dry-river-intake) — Water Supply Engineering, chapter 5 - [Short note: River intake](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ariver-intake-note) — Water Supply Engineering, chapter 5 - [Intake components and site factors](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Aintake-components-site-factors) — Water Supply Engineering, chapter 5 ## Related in other subjects - [Powerhouse general arrangement and dimensions](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Apowerhouse-arrangement-and-dimensions) — Hydropower Engineering, chapter 8, asked 3× - [Site preparation components and facility arrangement](https://www.bctengineer.com/question.md?key=semester_8%2Fconstruction_management%3Asite-preparation-facilities-urban) — Construction Management, chapter 6 - [Daily pondage run-of-river components](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Adaily-pondage-ror-components) — Power Plant Design, chapter 3 - [Bridge components sketch; river bank protection](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Abridge-sketch-components-river-bank-protection) — Transportation Engineering II, chapter 5