# Reservoir

The printing of reservoir output is controlled by entering "y" or "n" in the *reservoir* line in [print.prt](https://swatplus.gitbook.io/io-docs/introduction-1/simulation-settings/print.prt). In addition, a basin average of all reservoirs can be printed by entering "y" in the *basin\_res* line in [print.prt](https://swatplus.gitbook.io/io-docs/introduction-1/simulation-settings/print.prt). Reservoir output can be printed at daily, monthly, yearly, and average annual time steps. The names of the reservoir output files are as follows: 

* reservoir\_day.txt
* reservoir\_mon.txt
* reservoir\_yr.txt
* reservoir\_aa.txt
* basin\_res\_day.txt
* basin\_res\_mon.txt
* basin\_res\_yr.txt
* basin\_res\_aa.txt

| **Field**  | **Description**                                                 | **Unit** |
| ---------- | --------------------------------------------------------------- | -------- |
| jday       | Julian Day                                                      | n/a      |
| mon        | Month                                                           | n/a      |
| day        | Day of the month                                                | n/a      |
| yr         | Year                                                            | n/a      |
| unit       | ID of the object                                                | n/a      |
| gis\_id    | Object ID in GIS                                                | n/a      |
| name       | Name of the object or SWAT+ setup (basin outputs)               | n/a      |
| area       | Area of the reservoir                                           | ha       |
| precip     | Precipitation on the reservoir surface                          | ha-m     |
| evap       | Evaporation from the reservoir surface                          | ha-m     |
| seep       | Seepage out of the reservoir bottom                             | ha-m     |
| flo\_stor  | Flow storage in the reservoir                                   | m3       |
| sed\_stor  | Sediment storage in the reservoir                               | tons     |
| orgn\_stor | Organic nitrogen storage in the reservoir                       | kg       |
| sedp\_stor | Sediment phosphorus storage in the reservoir                    | kg       |
| no3\_stor  | Nitrate nitrogen storage in the reservoir                       | kg       |
| solp\_stor | Soluble phosphorus storage in the reservoir                     | kg       |
| chla\_stor | Chlorophyll-a storage in the reservoir                          | kg       |
| nh3\_stor  | Ammonia nitrogen storage in the reservoir                       | kg       |
| no2\_stor  | Nitrite nitrogen storage in the reservoir                       | kg       |
| cbod\_stor | Carbonaceous Biochemical Oxygen Demand storage in the reservoir | kg       |
| dox\_stor  | Dissolved oxygen storage in the reservoir                       | kg       |
| san\_stor  | Sand storage in the reservoir                                   | tons     |
| sil\_stor  | Silt storage in the reservoir                                   | tons     |
| cla\_stor  | Clay storage in the reservoir                                   | tons     |
| sag\_stor  | Small aggregate storage in the reservoir                        | tons     |
| lag\_stor  | Large aggregate storage in the reservoir                        | tons     |
| grv\_stor  | Gravel storage in the reservoir                                 | tons     |
| null       |                                                                 |          |
| flo\_in    | Flow into the reservoir                                         | m3       |
| sed\_in    | Sediment entering the reservoir                                 | tons     |
| orgn\_in   | Organic nitrogen entering the reservoir                         | kg       |
| sedp\_in   | Sediment phosphorus entering the reservoir                      | kg       |
| no3\_in    | Nitrate nitrogen entering the reservoir                         | kg       |
| solp\_in   | Soluble phosphorus entering the reservoir                       | kg       |
| chla\_in   | Chlorophyll-a entering the reservoir                            | kg       |
| nh3\_in    | Ammonia nitrogen entering the reservoir                         | kg       |
| no2\_in    | Nitrite nitrogen entering the reservoir                         | kg       |
| cbod\_in   | Carbonaceous Biochemical Oxygen Demand entering the reservoir   | kg       |
| dox\_in    | Dissolved oxygen entering the reservoir                         | kg       |
| san\_in    | Sand entering the reservoir                                     | tons     |
| sil\_in    | Silt entering the reservoir                                     | tons     |
| cla\_in    | Clay entering the reservoir                                     | tons     |
| sag\_in    | Small aggregates entering the reservoir                         | tons     |
| lag\_in    | Large aggregates entering the reservoir                         | tons     |
| grv\_in    | Gravel entering the reservoir                                   | tons     |
| null       |                                                                 |          |
| flo\_out   | Flow out of the reservoir                                       | m3       |
| sed\_out   | Sediment leaving the reservoir                                  | tons     |
| orgn\_out  | Organic nitrogen leaving the reservoir                          | kg       |
| sedp\_out  | Sediment phosphorus leaving the reservoir                       | kg       |
| no3\_out   | Nitrate nitrogen leaving the reservoir                          | kg       |
| solp\_out  | Soluble phosphorus leaving the reservoir                        | kg       |
| chla\_out  | Chlorophyll-a leaving the reservoir                             | kg       |
| nh3\_out   | Ammonia nitrogen leaving the reservoir                          | kg       |
| no2\_out   | Nitrite nitrogen leaving the reservoir                          | kg       |
| cbod\_out  | Carbonaceous Biochemical Oxygen Demand leaving the reservoir    | kg       |
| dox\_out   | Dissolved oxygen leaving the reservoir                          | kg       |
| san\_out   | Sand leaving the reservoir                                      | tons     |
| sil\_out   | Silt leaving the reservoir                                      | tons     |
| cla\_out   | Clay leaving the reservoir                                      | tons     |
| sag\_out   | Small aggregates leaving the reservoir                          | tons     |
| lag\_out   | Large aggregates leaving the reservoir                          | tons     |
| grv\_out   | Gravel leaving the reservoir                                    | tons     |
| null       |                                                                 |          |


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://swatplus.gitbook.io/io-docs/swat+-output-files/reservoir.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.