Issues

• [BUG] Large velocities on very shallow depths for 2d engine

  bug
  Bug

  HydroCouple/openswmm.engine#197 · Filter by author cbuahin opened on Oct 28, 2026 · Open Source SWMM Alpha 4
  

• CRASH-02: Fix an [XSECTIONS] row read before its link's own row writing past the conduit array in 5.3.0

  bug
  HydroCouple/openswmm.engine#178 · Filter by author corinne-wf-home opened on Oct 20, 2026
  1

  

• IO-10: Fix the number of barrels stored in a char (wraps above 127) in 5.3.0

  HydroCouple/openswmm.engine#177 · Filter by author corinne-wf-home opened on Oct 20, 2026
  1

• IO-11: Fix the Barrels item of IRREGULAR and STREET cross sections being ignored in 5.3.0

  HydroCouple/openswmm.engine#176 · Filter by author corinne-wf-home opened on Oct 20, 2026

• IO-13: Report invalid cross-section geometry with the link name instead of "invalid number" and no number, in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#175 · Filter by author corinne-wf-home opened on Oct 20, 2026

• CRASH-07: Fix cross-section table lookups converting an unchecked ratio to an int index in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#174 · Filter by author corinne-wf-home opened on Oct 20, 2026

• IO-29: Fix transect X1 line in the manual's 11-item layout being misread in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#173 · Filter by author corinne-wf-home opened on Oct 20, 2026
  1

• IO-12: Fix ellipse/arch size code overridden by Geom1 when Geom2 is 0, and fractional size codes, in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#172 · Filter by author corinne-wf-home opened on Oct 20, 2026

• CON-18: Fix Preissmann slot area that shrinks as head rises (SURCHARGE_METHOD SLOT) in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#171 · Filter by author corinne-wf-home opened on Oct 20, 2026
  1

• CON-17: Fix custom elliptical pipes taking a standard ellipse's area and radius in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#170 · Filter by author corinne-wf-home opened on Oct 20, 2026
  1

• NUM-24: Fix transect right end wall dropped from the wetted perimeter in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#169 · Filter by author corinne-wf-home opened on Oct 20, 2026

• NUM-23: Fix transect bank stations missed in SI units with a width factor in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#168 · Filter by author corinne-wf-home opened on Oct 20, 2026

• NUM-20: Fix standard ARCH size code 31 full hydraulic radius in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#167 · Filter by author corinne-wf-home opened on Oct 20, 2026

• NUM-07: Fix FORCE_MAIN full section factor (Hazen-Williams exponent under Manning) in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#166 · Filter by author corinne-wf-home opened on Oct 20, 2026
  2

• NUM-03: Fix RECT_ROUND round-bottom hydraulic radius in 5.3.0 and 6.0.0

  HydroCouple/openswmm.engine#164 · Filter by author cbuahin opened on Oct 20, 2026
  1

• [FEATURE] Mixed-flow pressurization: TPA closure + unsteady friction (both solvers) + comparison study

  enhancement
  HydroCouple/openswmm.engine#156 · Filter by author cbuahin opened on Aug 29, 2026
  2

  

• [BUG] 2D results render in the wrong location for models in feet-based CRS (HDF5 node coordinates are written in meters)

  bug
  HydroCouple/openswmm.engine#155 · Filter by author cbuahin opened on Aug 29, 2026
  

• [FEATURE] Nil Outfall Backflow Concentration Option

  enhancement
  HydroCouple/openswmm.engine#147 · Filter by author cbuahin opened on Aug 26, 2026
  2

  

• [BUG] Preissmann slot area is included in the momentum-equation velocity (dwflow.c:187)

  bug
  HydroCouple/openswmm.engine#144 · Filter by author cbuahin opened on Aug 22, 2026
  1

• [FEATURE] Option for having ONLY one detailed LID File instead of many

  enhancement
  HydroCouple/openswmm.engine#127 · Filter by author cbuahin opened on Aug 13, 2026

• [BUG] Incorrect Outfall Pollutographs

  bug
  HydroCouple/openswmm.engine#125 · Filter by author cbuahin opened on Aug 13, 2026

• [BUG] Set Limit on Land Use Coverages to 100% for Subcatchments

  bug
  HydroCouple/openswmm.engine#124 · Filter by author cbuahin opened on Aug 13, 2026
  

• [BUG] Is the default SWMM 6 the SWMM 5.3 Engine?

  bug
  HydroCouple/openswmm.engine#116 · Filter by author dickinsonre opened on Aug 7, 2026
  12

  

• Many Branches

  HydroCouple/openswmm.engine#105 · Filter by author dickinsonre opened on Jul 18, 2026
  4

• [DIFF] case sensitivity

  bug
  HydroCouple/openswmm.engine#96 · Filter by author wiesnerfriedman opened on Jul 13, 2026
  3