Adding a Demand

In this section an output node representing a municipal demand will be added to the system which will draw water from the reservoir.

Adding an output node

Add an output node to the system which will represent an urban demand that wil abstract water from the reservoir. Rename the node to 'Example demand'.

Adding an output node as a demand

Baseline demand

In the Baseline scenario set the following attributes on the Example demand node:

Baseline scenario

• 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 Example demand node

Create a new scenariao

Create a new scenario called 'With demand'. For a reminder on how to create a scenario please follow the link below.

Creating a New Scenario | WaterStrategywater-strategy.gitbook.io

Demand in the new scenario

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

Example demand

View and compare the reservoir volume

View the simulated_volume of the reservoir in this scenario and compare against the baseline.

Selecting baseline to compare

Reservoir volume comparison

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.

• 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.

• What is the maximum monthly spill from the reservoir in the simulation?

Hint: Look at the simulated_flow on the spill link node.

• Create a 'Monthly demand' scenario. Use the following video to help you implement a monthly profile demand, where the Example 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