Understanding extended period simulations

In the real world, water networks don’t operate at a single point in time. Demand changes through the day, tanks often fill overnight when electricity is cheapest, and pumps turn on and off in response to reservoir levels. An extended period simulation (EPS) lets you model how the system behaves as these conditions change, so you can check that it continues to perform as expected.

Steady-state vs extended period simulation

Feature	Steady-state	EPS
Timeline	A single point in time (e.g., peak hour).	A continuous simulation (e.g., 24–48 hours).
Tank Behavior	Treated as fixed-head nodes.	Fill and drain based on system flow.
Patterns	Fixed demand values.	Time-varying using patterns.
Best for	Peak capacity and worst-case checks.	Understanding how the system operates over time.

When an extended period simulation is essential

Understanding pressure over time: see how minimum and maximum pressures move through the day, not just at peak hour.
Tank performance: confirm tanks fill, drain, and turn over as expected.
Pump operation and run time: check how often pumps start, how long they run, and whether storage is being used the way you intended.
Energy cost calculations: estimate the cost of operating your system based on when pumps run.
Calibration confidence: compare model results against real data across a full day, not a single snapshot.
Water quality simulations: required for water age, chlorine decay, and source tracing.
Operational planning: test what happens during outages, valve closures, or changes in control logic.