> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/reservoirs/hydrology.res/vol_es-1.md).

# vol\_es

QSWAT+ assumes an average reservoir depth of 10 m, so the default volume of water needed to fill the reservoir to principal spillway is [area\_es](/io-docs/introduction-1/reservoirs/hydrology.res/area_es.md) \* 10.