CHANNEL DESIGN SOFTWARE
STREAM designs an open channel on ground you have actually surveyed. You draw the alignment, set the section and the lining; STREAM takes the bed elevations from the terrain, solves the hydraulics at every station with Manning, checks the design against freeboard, velocity and regime limits, and gives you the quantities, the drawings and the setting-out table.
A diversion channel carries surface water around something that must stay dry — a pit, a working bench, a stockpile area, a road. It is sized for a design storm: enough capacity to pass the peak discharge with freeboard to spare, and a velocity that neither scours the lining nor lets sediment settle out.
The difficulty is that all three constraints move together. A steeper bed carries more water but raises the velocity past what the lining can take; a wider section slows the flow but costs excavation and lining area. Because the bed follows real ground, the grade changes along the alignment — so the design has to be checked station by station, not once.
Draw the channel on the terrain, or turn a line you already have into the axis. Ground elevation at every station comes from the DEM, so the profile is the real one.
Normal depth, velocity, critical depth and Froude number are solved with Manning at each station, with the critical slope reported alongside so you can see exactly where the flow turns supercritical.
Enter catchment area, runoff coefficient, return period and storm duration and the peak discharge follows the rational method; the values can be captured directly from STREAM's hydrology analysis. A lateral catchment makes the discharge grow downstream, and both ends are reported.
Freeboard against USBR, flow regime, siltation below 0.6 m/s, the velocity the lining permits, adverse and level bed grades — each finding tells you what to do about it, not just that something is wrong.
Where supercritical flow returns to subcritical, a jump forms. It is reported as its own finding and marked on the profile, because it is the point where an unprotected channel gets damaged.
Choose a riprap lining and the required D50 stone size is computed from the Shields criterion for the velocity at that station.
Size by capacity for the narrowest section that meets the limits, or the most economic section that carries the same discharge with the least lining and excavation — with a warning if the economic section pushes the velocity past the lining limit.
Excavation, fill and lining quantities from the intersection with the ground, and a setting-out table with axis, bed edges and excavation-limit coordinates at every station, in the same coordinate system as the drawings.
Draw the channel route on the terrain, or select an existing line and make it the axis.
Enter catchment area, runoff coefficient, return period and storm duration, or capture them from the hydrology analysis, and the peak discharge follows the rational method.
Enter bed width, depth, left and right batter slopes, and choose the lining — the roughness follows from it.
Set the bed elevations and station grades on the profile. The ground elevation at each station comes from the DEM, so cut and fill are real.
Check normal depth, velocity, critical depth and Froude number station by station, and see where the bed grade exceeds the critical slope.
Work through freeboard, regime, siltation, lining velocity and adverse grade findings — each one names the value, the limit and the remedy.
Send plan, profile and cross-sections to DXF, the tables and the setting-out coordinates to CSV, and the design report to PDF.
It designs an open channel on surveyed terrain: alignment, invert profile, typical section and lining, with Manning hydraulics, design checks, quantities, drawings and a setting-out table.
Normal depth, velocity and Froude number come from Manning's equation at each station, with critical depth and critical slope reported alongside so the flow regime is explicit rather than assumed.
From the rational method — catchment area, runoff coefficient, rainfall intensity for your return period and storm duration. The catchment values can be taken straight from STREAM's hydrology analysis rather than typed in.
Yes. Enter a lateral catchment and the discharge grows downstream; the hydraulics are solved for the increased flow and the badge reports both the upstream and the downstream value.
Yes. With a riprap lining the required D50 stone size is computed from the Shields criterion at the velocity each station actually sees.
Yes. Apply to Terrain cuts the designed channel into the ground permanently. If you change the design afterwards the patch is marked stale, and re-applying refreshes it — it does not silently drift out of date.
No. The hydraulics are steady, station by station, with the flow regime and hydraulic jump locations identified. Unsteady routing, backwater profiles and sediment transport modelling are outside its scope.
No. The module covers the channel itself — alignment, section, lining, hydraulics and quantities. Hydraulic structures along it are not designed here.
Free beta for Windows x64. Works fully offline with GeoTIFF, LAS/LAZ and DXF.
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