STREAM-1D Workspace

Configure Reach Layout

STREAM-1D models one main channel and one optional tributary. Select which reaches form the main stem (merged in order) and which reach is the tributary, if any.

1. Main Stem Reaches

Main Stem Merge Order (Upstream to Downstream)

2. Tributary Reach

Layout Preview

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Terrain & Map Layers Settings

Model Calibration Data

Enter measured water surface elevations (WSEL) and estimated flow rates (Q) at existing cross-sections to display on the profile and cross-section plots.

Branch	Station	Observed WSEL (ft)	Observed Q (cfs)	Actions

Map Photos & GPS Notes

Upload geotagged field photos (containing GPS latitude and longitude in their metadata), or upload GPS data files (KML, GeoJSON, or CSV) to display notes and photo markers along the model centerline in the Plan View. You can also paste coordinates (latitude, longitude) manually using the table below.

📂 Choose File... No file selected

Latitude, Longitude	Mapped Station	Notes & Description	Actions

Steady Flow Summary

Steady-state hydraulic profile summary based on current inputs and geometry.

River STA	Distance	Flow	Chan. Inv.	WS elev.	Crit. Elev.	Energy G. Elev.	E.G. Slope	Vel.	Flow Area	Top width	froude num.

Culvert Performance Summary

Summary of culvert hydraulic performance across all structures in the current reach.

Bridge CAD Viewport

Design Parameters

Low Chord (ft)

High Chord (ft)

Pier Width (ft)

Number of Piers

Left Abutment

Width (ft)

Station (ft)

Top Elev (ft)

Right Abutment

Width (ft)

Station (ft)

Top Elev (ft)

Deck Vents / Slotted Openings

Edit Manning's n Values

Set Values:

Multiply:

Add:

River Station	Frcn (n/K)	Left Overbank (n #1)	Channel (n #2)	Right Overbank (n #3)

Edit Downstream Reach Lengths

Set Values:

Multiply:

Add:

River Station	Type	LOB	Channel	ROB

Inline Structure Weir Station Elevation Editor

Distance:

Width:

Weir Coef:

Row	Station (ft/m)	Elevation (ft/m)

U.S. Embankment SS:

D.S. Embankment SS:

Weir Crest Shape

Broad Crested Ogee

Spillway Approach Height (P):

Design Energy Head (Hd):

About STREAM-1D

Version 1.8.0 Open Source

STREAM-1D is a high-fidelity 1D hydrodynamic model for open-channel hydraulics. Simulate steady water surface profiles (Standard Step method) containing complex structures, composite channel friction, and custom geometry directly in the web browser. The computational solver is fully open source.

Designed and developed by Jason Lillywhite.

🌐

Visit Main Website lillywhitewater.com

View on GitHub github.com/jlillywh/STREAM-1D

📢

Release Notes

Version 1.8 (Bridge Abutment Profiles & Hydraulic Refinements)

Current Release

Added: Custom Bridge Abutment Profiles: Model custom, sloping bridge abutments using dedicated station-elevation profile tables for both the left and right abutments.
Added: Abutment Slope Station Helper: Built-in geometry tool that quickly establishes daylighting abutment slopes. Enter the top and toe stations, and the tool automatically samples the bridge deck's underside elevation at the top and the riverbed cross-section elevation at the toe.
Fixed: Weir Water Surface Elevation Accuracy: Resolved an issue where inline weirs or dam structures without custom roadway decks could produce an artificial spike in calculated water surface elevations (WSEL).
Fixed: Map Stability & Zoom Behavior: Fixed a bug where the GIS plan view map could intermittently fail to load or zoom out unexpectedly when switching views or opening models.
Fixed: Demo Map Centering: Example demo models now reliably open centered directly on the demo stream channel rather than displaying an off-target map view.
Fixed: Culvert Downstream Barrel Alignment: Preserves custom downstream barrel offsets (Departure Center X) when adjusting culvert crossing properties.
Added: Dashboard Descriptions & Community Forum: Project descriptions now appear directly in your project list for easier organization, and a direct link to the STREAM-1D Community Forum is available in the Help menu.

Version 1.7 (Culvert Multi-Group Center X)

Added: Independent Multi-Group Barrel Alignment: Moved Center X inputs to individual group tabs. Multiple barrel groups can now be positioned independently across the channel, and both plan/cross-section views render them at their correct offsets. Map dragging now shifts all groups relatively to maintain spacing.
Added: Decoupled Roadway and Barrel Skews: Separated roadway deck skew from culvert barrel alignment skew, allowing you to skew the barrel independently of the road deck.
Fixed: Sidebar Scroll Preservation: Details panel scroll positions are now saved and restored when editing inputs, preventing the view from resetting to the top.
Fixed: Simplified Sidebar: Removed the manual Bounding Cross-sections inputs panel, as bounding stations are now resolved automatically.

Version 1.6.4 (Manning's n & Downstream Reach Lengths Tables)

Manning's n Values Table: View and edit Left Overbank ($n_1$), Channel ($n_2$), and Right Overbank ($n_3$) values for all cross-sections in a unified, spreadsheet-like editor modal.
Downstream Reach Lengths Table: View and override Left Overbank (LOB), Channel, and Right Overbank (ROB) downstream reach lengths for all cross-sections simultaneously.
Bulk Range Math Operations: Set values, multiply by a factor, or add constants to selected regions (LOB, Channel, ROB, or All Regions) across all cross-sections in bulk.
Excel / Sheets Copy-Paste: Easily copy the parameter grids to Excel/Google Sheets in Tab-Separated Values (TSV) format, edit in bulk externally, and paste them back into the modal.

Version 1.6.3 (Blocked Obstructions & Ineffective Flow Areas CAD)

Interactive Blockage CAD & Grips: Draw and edit ineffective flow areas and blocked obstructions directly on the cross-section viewport. When geometry is unlocked, circle handles are rendered on the top corners of the blockages for click-and-drag resizing.
Quick Deletion: Quickly delete placed blockages and ineffective areas by holding down the `Ctrl/Cmd` key and clicking inside the shaded blockage shapes.
High-Fidelity Solver Accuracy: Fixed a boundary ramp interpolation bug inside the Rust WebAssembly engine to prevent blockage bounds from leaking into unobstructed open-channel segments, resulting in highly accurate velocity and energy grade line profiles.

Version 1.6.2 (Cross-Section Expansion/Contraction & Photo Relocation)

Cross-Section Loss Coefficients: Expose local expansion and contraction loss coefficients per cross-section in the Geometry Data Entry panel, ensuring full parity with HEC-RAS steady-state configurations.
XS Photos Tool Relocation: Relocate cross-section photos option from the main Data menu to the spreadsheet Tools dropdown menu with active, inactive, and linked status indicators.

Version 1.6.1 (Interactive Coordinate Readouts & UI Boundary Visibility)

Live Mouse Coordinate Readouts: Added interactive, monospace mouse tracking coordinates overlays in the bottom-right corner of both the Cross-Section and Water Surface Profile viewports.
Boundary Conditions Visibility: Expose scope functions to window, ensuring that selecting Subcritical or Supercritical regime correctly hides unused upstream/downstream boundary sections.

Version 1.6.0 (HEC-RAS Geometry Export & Inline Structures)

HEC-RAS Geometry Export: Download project geometries directly as HEC-RAS geometry files (`.g01`) in addition to JSON.
Inline Structures Support: Fully supports exporting bridges and culverts with dynamic deck profiles, abutments, and inverts.
Auto-Generated Bridge Piers: Automatically spaces and interpolates bridge piers using associated cross-section bank stations and elevations when custom coordinates are omitted.
Thalweg Alignment Fallbacks: Resolves missing culvert alignment offsets to the channel thalweg, matching the CAD viewport layout.

Version 1.5.0 (Levee Side Selector, Tributary Inflows, & Undo Reliability)

Levee Side Selector: Inline Left/Right side selector when the levee drawing tool is active.
Extract from DEM: Available from the Tools menu whenever the project is editable.
Tributary Inflows: Collapsible boundary-conditions panel to add inflow stations and set tributary flows.
Plotting & Spreadsheet Updates: Improvements to the profile plotter, CAD plan plotter, and deck spreadsheet editors.
Undo Reliability: More consistent undo for cross-section geometry edits, spreadsheet sidebar inputs, and levees.
Menu Cleanup: Removed Center on Channel from Tools and Clear All Geometry from the Edit menu; fixed nested submenu clipping on narrow screens.
Demo Experience: Curated example models on the dashboard; landing demo videos served from S3.

Version 1.4.0 (Interactive Lightbox, GIS Map Picking, & Nearest Station Mapping)

Interactive Levee Canvas CAD: Added support for CAD-style interactive drawing and horizontal dragging of left and right levees directly on the cross-section viewport canvas.
Unified Structures & Inline Weir Editors: Consolidated bridge, culvert, and weir spreadsheets under a single tab and introduced support for HEC-RAS inline weir editors and profile chart pan/zoom.
Nested Deck & Roadway Properties: Cleaned up sidebar properties forms by nesting deck/roadway edit lists inside parent bridge/culvert panels via dedicated modal popups.
Centerline CAD Path Operations: Support deleting centerline vertices by holding `Ctrl/Cmd` key and clicking on vertex markers, continuing path drawings, and auto-shifting element names during downstream extensions.
AI Agent Chat Box Redesign: Removed the double boundary border in the AI agent input box to maximize typing and viewport entry space.
Full-Screen Image Lightbox Modal: Integrated a premium blurred-backdrop image lightbox modal inside the workspace tab, letting you view full-size photos from Plan View map markers and coordinates tables without spawning new browser tabs.
Graphical Map Pick Coordinates: Added a "Pick Point on Map" button inside the field survey importer that temporarily overlays map indicators and registers Leaflet clicks directly to capture geographic coordinates.
Station ID Mapping: Replaced centerline coordinate chainage labels with the closest cross-section's actual River Station name (e.g. `550`) in Plan View map popups and the GPS Notes modal table.
Inline Photo Attachments: Added a camera icon button inside the GPS points list table, permitting users to attach, replace, or delete media attachments for coordinate points individually.
Robust File Importer Parsing: Implemented case-insensitive extension matching and fallback content-aware detection for KML/GeoJSON/CSV files, bypassing Windows Explorer and browser-level file dialog filtering.
Vertical Layout Consolidation: Removed the legacy Numeric Summary Outputs pane and optimized vertical cross-section plotting pane alignment.

Version 1.3.3 (High-Flow Overtopping & Co-pilot Context)

ConSpan GVF Drawdown Bug: Fixed a core hydraulic profile bug inside the STREAM-1D engine where culverts under high-flow outlet-control or pressure-flow conditions erroneously fell back to the downstream invert elevation.
AI Co-pilot Active Station Context: Provided the AI Co-pilot chatbot with the active station ID of the cross-section currently focused in the station view pane.
Plan View Map Legend Additions: Added Culvert Barrel and Roadway/Bridge Deck swatches to the Plan View map legend.

Version 1.3.2 (Longitudinal Profile Controls & Bank Lines)

Longitudinal Profile Options Menu: Added an Options dropdown menu to the profile view to control the visibility of the Legend and the Info Card.
Comprehensive Profile Legend: Added Left Bank, Right Bank, and Overbank lines to the profile legend for better design clarity.
Clamped Vertical Dragging: Resolved a lockout bug so that vertical pan/drag on the profile canvas correctly shifts the profile Y bounds in real-time when the cross-section vertical zoom is clamped.

Version 1.3.1 (Interactive CAD & UI Polishing)

AI Co-pilot Chatbot: Integrated chatbot in the Stream-1D workspace sidebar to assist with model alignment and navigation.
Reorganized Tools Dropdown: Consolidated spreadsheet secondary tools (Copy to Station, Shift Elev, CSV Import, Batch Extract, and Center on Channel) into a unified "Tools" menu, reducing visual clutter.
CAD Handle Layering & Overlaps: Fixed a z-index layout conflict to make cross-section end handles click-draggable even on extremely short cutlines.
Smoothing & Despiking: Implemented despiking and boundary smoothing to solve jagged water borders on the map view.
General Fixes: Trimmed decimal noise on station buttons and fixed the view-only warning trigger when renaming cross-sections.

Version 1.3 (LiDAR Mapping & Solver Streamlining)

LiDAR DEM Terrain Integration: Upload custom high-resolution GeoTIFF DEM rasters directly to the map and perform automated multi-point elevations extraction for cross-sections.
Interactive CAD Centerline & Survey Cuts: Draw river centerlines and cut custom cross-section alignments directly on top of the terrain raster, with real-time stationing and coordinate interpolation.
Unsteady Solver & GUI Decoupling: Removed all legacy unsteady routing timelines, hydrograph configuration modals, playback controls, and diagnostics to focus fully on high-performance steady-state hydraulics.

Version 1.2 (Interactive GIS & Geometry Editors)

GIS Satellite Backgrounds & Elevations: Integrated satellite imagery overlays (Esri World Imagery) with live opacity controls, and automated terrain lookup via the Open-Meteo Elevation API for georeferenced survey cuts.
Centerline Drawing & Graphic Cross-Section Cuts: Implemented visual path drawing tools to build channel centerlines and tributary alignments directly on the map, with live cross-section cutting geometry calculations.
Interactive Drag-to-Edit Handles: Added draggable handles to edit cross-sections, bank stations, and physical structure locations directly on both the GIS map and profile canvases.
Cross-Pane & Roadway Tab Sync: Connected selections globally so clicking a bridge or culvert updates active views in the longitudinal profile, cross-section detail, map, and the Roadway/Deck editor spreadsheet automatically.
Global Unit Conversion Toggle: Seamless conversion between US Customary (ft, cfs) and Metric (m, m³/s) unit systems across all calculations, plotters, tables, and configurations.
Bridge Deck Slot Designer: Added a visual CAD design view for bridge deck slot patterns, allowing interactive modeling of vents, repeating openings, and structural pier clearances directly within the deck view.
Wetted Area & Flood overlays: Fixed flood boundary tracing near complex bridge and culvert layouts.

Version 1.1 (Tributary Hydraulics & CAD Viewports)

Tributary & Junction Hydraulics: Added multi-reach routing and junction flow simulation stability for tributary channel networks.
WASM Culvert Engine API v8: Upgraded the core solver for stronger unsteady coupling, support for Pipe-Arch, Elliptical, Horseshoe shapes, and detailed per-step diagnostics.
CAD Viewport Modals & Skew Editors: Added dedicated layout drawing modals for culverts and bridges, complete with scale-accurate top/side views and interactive skew alignment grids.
Cross-Section Viewport Controls: Added mouse scroll and drag-to-pan capabilities to cross-section plots with live inline coordinates table editing.

Version 1.0 (Core Calculations & Launch)

Rust WebAssembly Engine: Replaced server-side simulation routines with high-performance WebAssembly (`stream1d.js`) running inside a background client worker for instant calculations.
Bridge Hydraulics with Piers: Added support for bridge modeling, including low-flow energy/momentum methods, pressure-flow, and combined weir overflow calculations.
FHWA Culvert Modeling: Integrated steady culvert calculations using standard Federal Highway Administration (FHWA) inlet and outlet control nomograph equations.
Composite Roughness: Added equivalent Manning's n calculations for channels with variable roughness zones.

Version 0.9.0-beta

Rust WebAssembly Engine: Replaced server-side simulation routines with a local compiled WebAssembly module (`stream1d.js`), enabling fast calculations.
Cross-Section Spreadsheet: Designed a grid-based geometry spreadsheet to enter and edit station-elevation cross-sections easily.
Interactive Charting: Implemented interactive Chart.js visualizations for cross-sections and water surface profile graphs.

Configure Reach Layout

Import Geometry & Structures

Export Geometry & Structures

Save Project

Share & Publish Project

Open Saved Project

Terrain & Map Layers Settings

Extracting Terrain Profiles

Loading Workspace

Batch Extraction Complete

Simulation & Numerical Settings

Model Calibration Data

Edit Centerline

Map Photos & GPS Notes

Photos for Station 1000.0

Upstream View

Downstream View

Reverse Flow Direction

Culvert Rating Curve

Steady Flow Summary

Culvert Performance Summary

Culvert CAD Viewport

Design Parameters

Deck / Roadway Data

Bridge CAD Viewport

Design Parameters

Edit Bridge Cross Section

Edit Manning's n Values

Edit Downstream Reach Lengths

Inline Structure Weir Station Elevation Editor

About STREAM-1D

STREAM-1D Workspace

Computational Engine

Third-Party Libraries & Technologies

Release Notes

Version 1.8 (Bridge Abutment Profiles & Hydraulic Refinements)

Version 1.7 (Culvert Multi-Group Center X)

Version 1.6.4 (Manning's n & Downstream Reach Lengths Tables)

Version 1.6.3 (Blocked Obstructions & Ineffective Flow Areas CAD)

Version 1.6.2 (Cross-Section Expansion/Contraction & Photo Relocation)

Version 1.6.1 (Interactive Coordinate Readouts & UI Boundary Visibility)

Version 1.6.0 (HEC-RAS Geometry Export & Inline Structures)

Version 1.5.0 (Levee Side Selector, Tributary Inflows, & Undo Reliability)

Version 1.4.0 (Interactive Lightbox, GIS Map Picking, & Nearest Station Mapping)

Version 1.3.3 (High-Flow Overtopping & Co-pilot Context)

Version 1.3.2 (Longitudinal Profile Controls & Bank Lines)

Version 1.3.1 (Interactive CAD & UI Polishing)

Version 1.3 (LiDAR Mapping & Solver Streamlining)

Version 1.2 (Interactive GIS & Geometry Editors)

Version 1.1 (Tributary Hydraulics & CAD Viewports)

Version 1.0 (Core Calculations & Launch)

Version 0.9.0-beta

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