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 models interim and ultimate build-out conditions.

Linked Elements

When multiple plans share common elements, such as off-site basins or existing channels that do not change between scenarios, HydraLink allows those 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.
• To link an element, tick Share across plans in its properties panel, or right-click it on the map and choose Link to Plan (Copy to Plan makes an independent copy instead).

Typical Use Cases

Scenario	Linked Elements	Plan-Specific Elements
Pre/Post Development	Off-site basins, existing reaches	On-site basins (different C/CN), proposed ponds, new channels
Design Alternatives	All basins, upstream reaches	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: selects the active plan. The map, data grid, and properties panel update to show that plan’s elements and results.
• Rename renames the active plan inline.
• New Plan asks for a name and creates an empty plan.
• Copy Plan duplicates the active plan, including all elements and connections. After naming the copy you are asked whether the copied elements should be linked to the source plan: answer No for an independent pre/post copy, Yes to keep them in sync.
• The trash-can Plan button (Delete Plan) removes the active plan after asking for confirmation (the project must always have at least one plan).
• Compare: shows a side-by-side comparison of linked elements across plans (enabled after running the solver on multiple plans). Only linked (shared) elements are compared; the dialog says so if there are none.

Creating a New Plan

1. Switch to the Plans tab in the ribbon toolbar.
2. Click New Plan and enter a descriptive name (e.g., “Post-Development” or “Alternative B”). Use Rename later if needed.
3. 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 in the Plans tab to view a side-by-side summary of linked elements across plans. The comparison table lists peak outflow from each plan for every storm event; with two plans a Δ column shows the difference. Select a row to see the plans' hydrographs overlaid. 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 belong to the project and apply to every plan automatically.