When you save an InfoDrainage model (.iddx) as a previous version, the software prepares a copy that an older release can open. Features that did not exist in that release are removed or converted automatically.
You can save back to InfoDrainage 2025.0 and later.
The following methods allow you to save an InfoDrainage model as a previous version:
In Save as type, select your preferred InfoDrainage version from the drop-down list. If you are on a later patch release (for example, 2027.1), the list typically includes your current version, 2027.0, 2026.0, and 2025.0.
Changes are cumulative. Saving to an older version includes every change listed for newer save targets, plus any additional changes for that version.
When saving from a release later than 2027.0 (such as 2027.1):
Discarded:
Analysis results (Deluge, 1D, 1D-2D) and Rational results on connections
Tables column setup
Flexible Reporting column setup
Model properties and features introduced after 2027.0
Modified:
External rainfall library - rainfall data is stored inside the .iddx file
Variable Depth Channels - converted to an equivalent Rectangular, Trapezoidal, Triangular, or Custom Open Channel (see below)
Includes all changes listed for 2027.0, plus:
Modified:
Flow paths - all flow paths under the AutoProfile Flow Paths section are saved as User Flow Paths
Bioretention inlet destinations remapped:
Soil Layer → Subsurface Area
Storage Layer → Subsurface Area
Surface Layer → Ponding Area
Horton infiltration decay constant - rounded up to a whole number (for example, 2.5 becomes 3)
Includes all changes listed for 2027.0 and 2026.0, plus:
Discarded:
Land Use and Soil Type definitions
Land Use calculation cache (but not the resulting values)
Modified:
Trimmed Desbordes rainfall - converted to Known Rainfall (Extended Desbordes is unchanged)
Arch and Ellipse connections - converted to Box Culvert
Variable Depth Channels
Each Variable Depth Channel is replaced with a standard channel type using whichever end of the channel has the smaller cross-section area:
| Cross-section shape | Converted to |
|---|---|
|
Both side slopes are zero |
Rectangular Channel |
|
Both side slopes are equal |
Trapezoidal Channel |
|
Base width is zero and right side slope is zero |
Triangular Channel |
|
Any other shape |
Custom Open Channel |
Trimmed Desbordes rainfall
Only rainfalls with Method set to Trimmed are affected
A storm record is created for each storm duration that was in use
The Known Rainfall is named from the Desbordes settings, for example: Desbordes-2-Region3-Trimmed-7.5-0.31-3.8-0.22-0.65