> 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/wetlands/hydrology.wet/hru_es.md).

# hru\_es

The fraction of HRU area at emergency spillway is multiplied with the HRU area to calculate the emergency surface area in ha. However, this values is not used in any subsequent calculations.