---
title: "Functions of head regulator, cross regulator, escape"
subject: "Irrigation and Drainage Engineering"
chapter: 7
key: "semester_6/irrigation_and_drainage_engineering:head-cross-regulator-escape-functions"
source: https://www.bctengineer.com/q/semester_6/irrigation_and_drainage_engineering/head-cross-regulator-escape-functions
site: BCT Engineering
---

# Functions of head regulator, cross regulator, escape

Irrigation and Drainage Engineering · Chapter 7: Regulating Structures

- Asked in: 2080 Chaitra, 3 marks
- Video: [DHS Module2 - Canal Regulators - Head regulator and Cross regulator](https://www.youtube.com/watch?v=Am1OUSbupss) — AM CIVIL ACADEMY
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/irrigation_and_drainage_engineering/head-cross-regulator-escape-functions
- Whole chapter: https://www.bctengineer.com/md/semester_6/irrigation_and_drainage_engineering/chapter-7

## Question

Describe the function of head regulator, cross regulator and escape.

## Short answer

Head regulator controls discharge into an off-taking canal, excludes silt, and shuts off supply. Cross regulator raises water level in parent canal to feed off-takes and regulates downstream flow. Escape releases surplus water into a drain to prevent overtopping, enables canal emptying and silt flushing.

## Answer

**Head regulator:** a gated structure at the head of an off-taking canal or distributary. It regulates the discharge entering the off-take, controls the entry of silt, measures the discharge, and shuts off the supply during floods or repairs.

**Cross regulator:** a gated structure built across the parent canal just downstream of an off-take. It raises (heads up) the water level in the parent canal so that the off-taking channel gets its full share even when the supply is low, regulates the discharge passing to the downstream reach, and allows the canal to be closed for repair.

**Escape:** a structure that discharges surplus canal water into a natural drain. It protects the canal from overtopping and breaches caused by excess rainwater or faulty operation, empties the canal in an emergency or for repairs, and (as a scouring escape) flushes out silt.

## Check yourself

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

1. Which is a function of the head regulator?
   A. Raises parent canal level
   B. Disposes surplus
   C. Regulates discharge entering the off-take and controls silt
   D. Drops the bed
   Answer: C. It sits at the head of the off-take. (Key point: Head regulator)

2. Why does a cross regulator head up water in the parent canal?
   A. To disposing surplus water
   B. To measure silt
   C. To reduce velocity in the outlet
   D. So the off-take gets its full share even when supply is low
   Answer: D. It is just downstream of the off-take. (Key point: Cross regulator)

3. What is a scouring escape used for?
   A. Flushing silt from the canal in addition to disposing surplus water
   B. Raising level
   C. Feeding the water course
   D. Measuring discharge
   Answer: A. Scouring escape flushes silt. (Key point: Escape)

## Related in Irrigation and Drainage Engineering

- [Functions of head and cross regulator](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Ahead-cross-regulator-functions-sketch) — Irrigation and Drainage Engineering, chapter 7, asked 6×
- [Design procedure: cross and distributary head regulator](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Across-distributary-regulator-design-procedure) — Irrigation and Drainage Engineering, chapter 7
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