Drainage Analysis for Civil 3D 2026.1

General Stormwater Control Enhancements

• Ponds, Underground Storage objects, and Channels can be viewed in Autodesk Construction Cloud.
• Ponds and Underground Storage can now be added to the Model Viewer.
• In the Prospector, Stormwater Controls have been moved from the Pipe Networks node to their own first level node.
• The LIST command now displays properties for Ponds and Underground Storage.
• Ponds and Channel corridors have been added to the Data Shortcuts Editor.

Tech Preview 2026 Objects

• Drawings containing Pond, Underground Storage, and Channel objects from the 2026 Tech Preview will open and display correctly in this 2026.1 release. Version compatibility and tracking is maintained.
• While Drainage Analysis functions normally, it is not possible to create or edit 2026 Tech Preview drainage design object geometry or properties.
• A warning dialog will display to indicate 2026 Tech Preview object incompatibility with Civil 3D Drainage Analysis.
• To update 2026 Tech Preview objects to the current version for editing, run AECCDRAINAGEDESIGNUPGRADE from the command line.

Pond Enhancements

• Ponds can now be shared between drawings using Data Shortcuts and Data References (DREF).
• The Storage tab on the Pond Properties dialog box has been redesigned for clarity.
• Ponds can now be created from Surfaces.
• Ponds can also be updated using the Redefine from Surface command.
• Pond now have new type classifications.
• Conceptual ponds are sketched in the drawing.
• Surface-Based ponds are created from Surfaces.
• Four new commands are available for editing pond grading:
• Quick Edit Pond
• Add Side Slope
• Add Contour
• Delete Contour
• We can now adjust slope and volume of a pond from modifying the Pond object in canvas.
• This includes adding slopes, editing slopes, deleting slope contours, adding contours and editing contour elevations.
• The Add Curves command has been renamed to Fillet Pond.
• The Stage Storage Curve for surface-based ponds can be configured using the "Depth increment" or "User-defined" modes.
• Pond volume calculation has been improved.
• Pond Style selection drop-downs is available in all Pond dialog boxes.

Channel Enhancements

• Added the CreateChannel command.
• Additional cross section shapes are available for Triangular, Rectangular, and Custom channel sections.
• A custom Channel Section can be defined manually, by importing points from a CSV file, or by picking a subassembly in the drawing.
• A custom Channel Section can be defined by importing from an existing subassembly in the drawing.
• The Station Range for a Channel Baseline can be customized (Raw Station).
• Alignment and Profile as Channel Baseline support has been implemented for Channel creation.
• Channel command and feature settings are now available.

Underground Storage Enhancements

• We can now select an Underground Storage and create, copy, and edit its Plan view Style from the contextual menu.
• Added the ability to display the proportion of empty space (voids) in a stage depth for water storage.

Rainfall Manager Enhancements

• User interface improvements were implemented to easily create, organize, modify, and exchange various rainfall data.
• Added Distribution Based Rainfall in order to create rainfall data based on a rainfall depth applied to a rainfall distribution.
• Added the ability to create a Distribution Based rainfall event based on SCS rainfall distributions and a valid rainfall depth (0 to 10080 mm).
• Added the ability to import and export individual or sets of rainfall data with a Rainfall Library (*.RAIN) file in order to share with other drawings.

Drainage Analysis Enhancements

• Added individual and total system outfall details to the Drainage System tab of analysis results.
• Export option enhancements include selection of current result columns, all results columns, or exclusion of results entirely.
• Exported analysis data now includes rainfall and input data.
• Additional tabs of input data are now included in the analysis exported Excel file. These include SBUH Runoff, Structure, SCS Runoff, SWMM, Analysis Criteria, Stormwater Controls (Ponds and Underground Storage), Connections (pipes and channels), Stormwater Control Outlet, and Time Area Runoff.
• Added support to pass bypass flows from an inlet structure to the downstream target inlet structure.