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.

Creating a new scenario | Water Strategy

4. In the 'Mosetse demand' scenario, set the max_flow of the Mosetse demand to 0.1 Mm3/day and run this scenario .

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