# Adding a demand In this section an output node representing a municiple demand will be added to the system which will draw water from the reservoir. 1. Add an **output** node to the system which will represent an urban demand that wil abstract water from the reservoir. Rename the node to 'Mosetse demand'.
2. In the **Baseline** scenaio set the following attributes on the **Mosetse demand** node:
* **max\_flow** = 0. This represents a deamnd of 0 Mm3/day. * **allocation\_penalty** = -1000. This represents a high priority for water allocation

The attributes defined on the Mosetse demand node.

3. **Create a new scenario called 'Mosetse demand'.** For a reminder on how to create a scenario please follow the link below. {% embed url="" %}
4. In the **'Mosetse demand'** scenario, set the **max\_flow** of the Mosetse demand to 0.1 Mm3/day and run this scenario ![](https://530325344-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOe4DHiaeqejzGopyV9BO%2Fuploads%2F9hy5glSufj2d7N64oRvK%2Fimage.png?alt=media\&token=3afc51de-0d74-4b66-acb5-3d445329f6fe).
4. View the **simulated\_volume** of the reservoir in this scenario and compare against the baseline.
## Exercises and questions In this case, we are modelling the 'live' storage of the reservoir. When the reservoir goes to 0 storage in the model there is still dead storage in the system. At the dead storage level, the remaining water isn't able to be released. 1. **How high can the demand go before the reservoir empties to its dead storage?** *To do this, create a new scenario and change the max\_flow of the demand node and rerun the model multiple times until the reservoir reaches 0 storage.* 2. **What is the maximum monthly spill from the reservoir in the simulation?** *Hint: Look at the simulated\_flow on the spill link node.* 3. **Create a 'Monthly demand' scenario. Use the following video to help you implement a monthly profile demand, where the Mosetse demand changes based on the months:**\ \ Jan-Mar: 0.1 Mm3/day\ April-June: 0.06 Mm3/day\ July-Sept: 0.07 Mm3/day\ Sept-Dec: 0.09 MM3/day
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