Engineering English
Runoff
Civil Engineering · Last updated: July 30, 2026 · How this entry was written
Definition: Runoff is the flow of water that occurs when excess water from rain, meltwater, or other sources flows over the land surface. It is a primary component of the water cycle and a key input for hydrological modeling.
Example in context
“The engineer calculated the runoff volume for the 100-year storm using the rational method.”
“Mühendis, rasyonel yöntemi kullanarak 100 yıllık fırtına için yüzey akışı hacmini hesapladı.”
Where engineers use it
Runoff is used in hydrologic studies for flood prediction, drainage design, and water balance calculations. Engineers need it to size stormwater infrastructure such as culverts and retention basins.
Practice: can you use “Runoff” at work?
You are designing a detention pond and need to estimate the runoff from a 10-year storm. Explain the method you will use to calculate it.
Show a model answer
“The runoff volume is a key parameter in drainage design.”
“Runoff” in 21 languages
| English | Runoff |
|---|---|
| Turkish | yüzey akışı |
| French | ruissellement |
| German | Abfluss |
| Spanish | escorrentía |
| Chinese | 径流 |
| Arabic | الجريان السطحي |
| Portuguese | escoamento superficial |
| Russian | поверхностный сток |
| Japanese | 流出 |
| Italian | ruscellamento |
| Vietnamese | dòng chảy |
| Hindi | अपवाह |
| Thai | น้ำไหลบ่า |
| Indonesian | limpasan permukaan |
| Korean | 유출 |
| Bengali | প্রবাহ |
| Dutch | afstroming |
| Swedish | avrinning |
| Finnish | valuma |
| Ukrainian | поверхневий стік |
Frequently asked questions
What does Runoff mean in engineering?
Runoff is the flow of water that occurs when excess water from rain, meltwater, or other sources flows over the land surface. It is a primary component of the water cycle and a key input for hydrological modeling. In Civil Engineering, the term carries a usage-frequency rating of 10/10 in the Engineering English library.
How do you pronounce Runoff?
Runoff is pronounced /ˈrʌnˌɔːf/ (IPA). The Engineering English app plays audio for the term and checks your pronunciation with speech recognition.
How is Runoff used in a sentence?
Example from an engineering context: “The engineer calculated the runoff volume for the 100-year storm using the rational method.”
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