Plans & Scenarios
Overview
HydraLink’s plan management system enables engineers to compare multiple drainage scenarios within a single project file. Plans are commonly used to evaluate pre-development vs. post-development conditions, compare design alternatives, or test different configurations without duplicating data.
What is a Plan?
A plan is a self-contained configuration of hydrologic and hydraulic elements within a project. Each plan defines its own drainage network with its own set of elements, connections, and parameters. A single HydraLink project can contain multiple plans, and the solver runs each plan independently.
Common uses for multiple plans include:
- Pre-development vs. post-development — Model existing conditions and proposed conditions side by side to compare peak flows, runoff volumes, and detention requirements.
- Design alternatives — Evaluate different pond sizes, outlet configurations, routing approaches, or development layouts.
- Phased development — Model interim and ultimate build-out conditions.
Linked Elements
When multiple plans share common elements — such as off-site basins, existing channels, or storm data that does not change between scenarios — HydraLink allows these elements to be linked across plans.
How Linked Elements Work
- A linked element exists in multiple plans but shares a single set of properties.
- When you edit a linked element’s parameters in any plan, the changes are automatically reflected in all plans that share that element.
- This eliminates the need to manually update common data across scenarios and ensures consistency.
Typical Use Cases
| Scenario | Linked Elements | Plan-Specific Elements |
|---|---|---|
| Pre/Post Development | Off-site basins, existing reaches, storm events | On-site basins (different C/CN), proposed ponds, new channels |
| Design Alternatives | All basins, upstream reaches, storm events | Different pond sizes, outlet configurations, or routing |
| Phased Development | Off-site elements, completed phases | Future phase basins and infrastructure |
Working with Plans
The Plans Tab
Plan management is accessed from the Plans tab in the ribbon toolbar. The tab contains the following controls:
- Plan dropdown — select the active plan. The map, data grid, and properties panel update to show that plan’s elements and results.
- Rename — rename the active plan inline.
- New Plan — create a new empty plan.
- Copy Plan — duplicate the active plan, including all elements and connections.
- Delete Plan — remove the active plan (the project must always have at least one plan).
- Compare Plans — view a side-by-side comparison of linked elements across plans (enabled after running the solver on multiple plans).
Creating a New Plan
- Switch to the Plans tab in the ribbon toolbar.
- Click New Plan to create a new plan.
- Click Rename to give the plan a descriptive name (e.g., “Post-Development” or “Alternative B”).
- Add elements to the plan or link existing elements from other plans.
Switching Between Plans
Use the plan dropdown in the Plans tab to switch between plans. The map view, data grid, and properties panel update to show the active plan’s configuration. Results are computed and stored per plan.
Comparing Results
After running the solver on all plans, click Compare Plans in the Plans tab to view a side-by-side summary of linked elements across plans. The comparison table shows outflows from each plan for every storm event, along with the difference and percent change. This allows quick evaluation of how different design choices affect system performance.
Considerations
- Link elements that represent unchanged conditions (off-site areas, existing infrastructure) to avoid data duplication and ensure consistency across scenarios.
- Use separate (non-linked) elements for anything that changes between scenarios, such as on-site basins with different land use or proposed ponds with different configurations.
- Give plans clear, descriptive names so it is easy to identify which scenario each represents.
- Storm events are typically shared across all plans since rainfall conditions do not change between development scenarios.