> For the complete documentation index, see [llms.txt](https://water-strategy.gitbook.io/waterstrategy/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://water-strategy.gitbook.io/waterstrategy/modeling-basics/node-types/water-storage/storage-node.md).

# Storage Node

## General Description

The **storage node** is a general node that can store water, which have a minimum and maximum volume restrictions. [API Reference](https://pywr.github.io/pywr-docs/master/api/generated/pywr.nodes.Storage.html).

## Primary Attributes

<table><thead><tr><th width="180.33333333333331">Name</th><th width="316">Description</th><th>Required</th></tr></thead><tbody><tr><td>allocation penalty</td><td>The cost per unit flow via the node</td><td>Optional</td></tr><tr><td>min_volume</td><td>The minimum volume of the storage. Defaults to 0.0</td><td>Optional</td></tr><tr><td>max_volume</td><td>The maximum volume of the storage. Defaults to 0.0</td><td>Required,  defaults to 0 if not entered</td></tr><tr><td>initial_volume, initial_volume_pc</td><td>Specify initial volume in either absolute or proportional terms. Both are required if <em>max_volume</em> is a parameter because the parameter will not be evaluated at the first time-step. If both are given and <em>max_volume</em> is not a Parameter, then the absolute value is ignored</td><td>One is required</td></tr><tr><td>area, level</td><td>Optional float or Parameter defining the area and level of the storage node. These values are accessible through the <em>get_area</em> and <em>get_level</em> methods respectively</td><td>Optional</td></tr></tbody></table>

## Examples

coming soon...


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