Getting Started with HydraStorm

This guide walks you through your first use of HydraStorm, from loading the plugin in Civil 3D to exporting a completed storm drain analysis. Follow these steps in order to get a working hydraulic model with results you can review and submit.

1 Install and Open HydraStorm

Download the HydraStorm installer from bezaleldesignlab.com and run it. Start Civil 3D 2025 or newer — HydraStorm loads automatically, and you'll see a HydraStorm ribbon tab. Click the HydraStorm button there, or type HYDRASTORM at the command line, to open the window. It opens as a modeless dialog alongside your drawing, so you can continue working in Civil 3D while the plugin is active.

2 Select a Pipe Network

In the HydraStorm toolbar, choose your pipe network from the Network dropdown. This reads all Civil 3D Pipe Network objects in the current drawing, along with pipe and structure geometry, inverts, sizes, part families, and part descriptions from the selected network.

If you create or modify networks in Civil 3D while HydraStorm is open, close and reopen the project (or reopen the HydraStorm window) so the network list re-reads the drawing.

3 Configure Project Settings

Click the Settings button in the toolbar to open the Project Settings dialog. Before running your first calculation, review these key settings:

• Hydrology Mode — Choose how design flows are determined:
  • Peak Flows Only (default) — enter Q directly at each structure
  • HydraLink — import flows from a HydraLink project
  • Parcels — read drainage areas from Civil 3D parcels
  • Manual — enter area, C, and Tc per node for rational method
• Storm Events — On the Hydrology tab's Storm Events sub-tab, add the return periods this project uses and assign each one a role (Design or Check) for the storm drain, culvert, and inlet modules independently.
• Manning's n — Set the default roughness coefficient for new pipes on the Calculation tab.

The design standard (junction loss library — e.g., HEC-22, iSWM/NCTCOG, or a custom standard) is selected separately, from the Tables > Structures... dialog. If the standard includes design criteria, you'll be prompted to apply municipality-specific defaults.

4 Set Alignment Design Types

Each alignment in your pipe network is classified as one of three design types:

• Storm Drain (default) — Standard HGL/EGL calculation with junction losses
• Culvert — FHWA HDS-5 headwater analysis (see Culvert Analysis)
• None — Excluded from calculations

Set alignment types in Project Settings or the Alignment Types editor under the Tables menu. If your network is all storm drain pipes, you can skip this step.

5 Set Up Hydrology

Enter design flows for each structure. The method depends on the hydrology mode you selected:

• Peak Flows Only — Enter Q (cfs) directly in the Hydrology Table or in the results grid. This is the simplest approach when you already have flows from an external source.
• HydraLink — Browse to your .hyd or .hlresults file in Project Settings > Hydrology. HydraStorm automatically matches HydraLink basins and junctions to your pipe network structures by name, then by spatial proximity.
• Rational Method (Manual or Parcels) — First, configure your IDF data source (NOAA Atlas 14 fetch, CSV import, or manual E/B/D coefficients). Then enter the runoff coefficient (C), drainage area (acres), and time of concentration (Tc) for each node.

See Hydrology Modes for a detailed explanation of each mode.

6 Assign Junction Loss Types

Open Tables > Structures.... Each structure in your network needs a junction loss type that determines how energy losses are calculated at that node.

1. Select a design standard from the dropdown — choose HEC-22, iSWM (NCTCOG), or a custom standard that matches your municipality's requirements.
2. HydraStorm suggests a loss type for each structure based on its Civil 3D part description, using its smart memory system — suggestions are shown as a badge in the Suggestion column, never applied automatically.
3. Click Accept All to accept every pending suggestion, Accept Selected to accept just the highlighted rows, or assign a Loss Type yourself from the dropdown in each row. As you confirm or correct assignments, HydraStorm learns your preferences for future projects.

7 Configure Inlets (Optional)

If your project requires inlet capacity analysis, switch to the Inlet tab and click Library... to select an inlet library (e.g., HEC-22, iSWM, or municipality-specific). Then, for each inlet:

1. Assign an inlet type, specifying whether it's a sag or on-grade inlet.
2. Configure gutter cross-section geometry per inlet, or apply a roadway template.
3. Set bypass routing targets for each inlet.

8 Calculate

Press F5 (there is no dedicated Calculate button — calculations also run automatically as you edit properties, on a 300ms debounce). HydraStorm runs the full analysis pipeline:

1. Flow computation (upstream to downstream) — Accumulates flows through the network using topological ordering.
2. Inlet analysis (if enabled) — Computes capture and bypass at each inlet, feeding captured flows into the pipe network.
3. HGL/EGL analysis (downstream to upstream) — Propagates hydraulic grade line and energy grade line from outfall boundary conditions toward headwaters.
4. Culvert analysis (if culvert alignments exist) — Computes HDS-5 headwater for culvert pipes.
5. Compliance evaluation — Checks each pipe against design criteria (velocity, cover, HGL clearance).

Results appear immediately in the results grid, and the profile view updates to show the computed HGL and EGL lines.

9 Review Results

Examine the results grid for any issues. HydraStorm tracks compliance with color-coded indicators:

• Green — All design criteria pass
• Yellow — Some failures, but all have been reviewed and acknowledged
• Red — Unresolved compliance failures (e.g., HGL above rim, velocity out of range, insufficient cover)

The Comply column shows a score like "4/6" (4 of 6 checks passed). Hover for details on each check. If a failure is intentional, right-click the pipe and choose Acknowledge Check Failures....

In the profile view, toggle these overlays to visualize the hydraulic analysis:

• HGL — Hydraulic Grade Line (water surface)
• EGL — Energy Grade Line (total energy)
• Ground — Existing ground surface along the alignment
• Crossings — Utility crossings with clearance violations highlighted

10 Edit and Iterate

Adjust pipe parameters to resolve compliance issues. Inverts, size, slope, and Manning's n are edited directly in the results grid; shape, part family, and junction loss type are edited in the property panel next to the profile. The profile and calculations update live as you make changes.

Use the editing tools for efficient adjustments:

• Raise / Lower (Ctrl+Shift+R) — Shift both inverts uniformly (preserves slope)
• Set Slope (Ctrl+Shift+L) — Apply a specific slope with anchor selection
• Match to Adjacent — Align inverts, crowns, or centerlines with the neighboring pipe (right-click context menu)
• Match Slope (Ctrl+M) — Set a continuous slope across multiple selected pipes

11 Auto Design (Optional)

Click Auto (in the property panel) to let HydraStorm suggest pipe sizes that satisfy your design constraints. The sizing engine selects the smallest standard pipe size from the active parts list that meets capacity, velocity, and HGL cover requirements. It works upstream from the outfall and backtracks downstream when HGL violations are detected. Sizing applies to the alignment currently shown in the profile view — pipes on other alignments keep their sizes and act as fixed hydraulic context.

Review the suggested sizes, then click Apply (in the property panel) to accept or Discard to revert. See Auto Design for details.

12 Apply Changes to Civil 3D

When you are satisfied with your design, click Apply (pinned at the bottom of the property panel) to write all edits back to the Civil 3D pipe network objects. This updates pipe invert elevations, pipe sizes, and Manning's n values.

If you need to undo your changes, click Discard to revert to the last applied snapshot.

13 Create Profiles and Labels

Once your design is finalized and applied to Civil 3D, open the Output ▾ menu in the toolbar:

• Create HGL Profiles generates HGL layout profiles in Civil 3D for the storm(s) configured in Project Settings > Output.
• Apply Label Styles applies your configured pipe and structure label styles to the profile views, annotating sizes, slopes, inverts, and lengths.

See Profiles & Labels for details on configuring label styles and profile view options.

14 Export Results

From the Output ▾ menu, click Export to CSV (or press Ctrl+E) to export the current results grid to a CSV file for verification, submittal, or use in other tools. Separate CSV exports are available for the storm drain, inlet, and culvert results grids from their respective tabs.

See Export for details on the export format and customization options.