swmm-solver

Build 5.2.4 (Aug 2023)

Engine Updates:

1. A potential mismatch between reported pollutant Surface Runoff mass and conveyance system Wet Weather Inflow mass in a run's Status Report was fixed. #133

2. The test for invalid input data for an LID unit with an underdrain was fixed.

3. Improvements and corrections were made to the calculation of water flux rates between layers in Bio-Retention, Permeable Pavement, and Infiltration Trench LID units.

4. The hydraulic head seen by a storage layer underdrain in a Permeable Pavement LID unit with a soil layer above it was corrected.

5. A bug in retrieving the backing parameters for a Street cross-section was fixed.

6. The generation of transect points for a Street cross- section with a depressed gutter was corrected.

7. The calculation of gutter slope for Street links with depressed gutters was corrected.

8. The calculation of the effective hydraulic head seen within a curb inlet with an inclined throat opening was corrected.

9. Conduit evaporation and seepage loss over a time step is now limited to the conduit's current volume instead of its flow rate under dynamic wave flow routing.

10. A conduit's evaporation and seepage loss is now split evenly between its end nodes instead of just to the upstream node.

11. The default values for Inertial Damping and Variable Time Step options were made compatible with those used by the GUI

swmm-solver

Build 5.2.3 (Feb 2023)

Engine Updates:

1. Double counting of initial moisture volume in the drainage
   mat layer of a green roof LID unit was fixed. (#102 )

swmm-solver

Build 5.2.2 (Dec 2022)

Engine Updates:

1. Long run times occurring when the simulation duration exceeded
   the end of an externally applied time series were eliminated.

2. A bug introduced in 5.2.0 causing the math expression evaluator
   to compute ab^c as (ab)^c instead of a*(b^c) was fixed.

3. A check was added to the dimensions supplied for the Modified
   Baskethandle and Round-Rectangular cross sections to insure that
   the computed height of the rounded portion does not exceed the
   total height. (#89)

4. Additional performance statistics were added to the Street Flow
   Summary table in the project's report file.

5. The warning messages removed in release 5.2.1 about raising a
   node's maximum depth and adjusting a conduit's elevation drop
   were restored.

6. The values reported for storage unit evaporation and exfiltration
   loss as a percentage of total storage volume were corrected. (#97)

7. The default number of threads used for dynamic wave flow routing
   was changed to 1 to be consistent with the User's Manual and
   with the GUI.

swmm-solver

Build 5.2.1 (Aug 2022)

Engine Updates:

1. Use of the Normal Flow Limited feature for dynamic wave flow
   routing is now optional.

2. A refactoring bug causing excessive execution times for projects
   with control rules has been fixed.

3. For kinematic wave storage routing, after convergence is obtained
   the reported depth is based on the last volume value rather than
   the next trial depth.

4. Corrections were made to the geometry tables for the Egg shaped
   cross section at the two lowest relative depth levels.

5. The practice of setting a dry node's pollutant concentration to
   0 even when it receives non-zero pollutant inflow (as introduced
   in release 5.2.0) has been dropped.

6. When there is no inflow to a non-storage node its water quality
   concentration now remains unchanged rather than being set to 0.

7. The definition of F_OFF in output.c was corrected for non-MS C/C++
   compilers.

8. To eliminate having an excessive number of warning messages appear
   in the Status Report:

   • a message is no longer issued when a node's maximum depth is
     raised to match the crown of the highest connecting conduit.
   • a message is no longer issued when a conduit's elevation drop
     or slope is adjusted to not fall below minimum allowed values.

swmm-solver

Build 5.2.0 (Feb 2022)

Engine Updates:

1. Support has been added for modeling street runoff capture by inlet drains:

• A new Street cross-section type, defined in the [STREETS] section of an input file, was added to the set of conduit cross-section shapes.
• A new Inlet object, specified in the [INLETS] section of an input file, was added to select the type and sizing of an inlet structure that captures street runoff.
• A new conduit property, defined in the [INLET_USAGE] section of an input file, was added to place inlets in a Street
  conduit and connect them to a sewer system node.
• Inlet capture analysis using the HEC-22 equations or custom capture curves has been interfaced with SWMM's flow routing methods.
• A Street Summary table that displays summary results for each Street conduit and Inlet, including peak flow depth and spread, has been added to the list of Summary Reports.

2. A Type 5 variable speed pump that obeys the pump affinity laws relating head and flow to pump speed was added.

3. Storage Curve options now include several pre-defined shapes (cylinders, paraboloids, cones and pyramids) whose geometry is based on analytical formulas

4. Several new quantities, including past n-hour rainfall, were added to the properties that can appear in control rule condition clauses.

5. Control rule condition clauses were expanded to include named variables and math expressions.

6. A listing of the nodes with the highest flow routing non- convergence frequency was added to the Status Report. (#81)

7. Support was added for the latest version of NOAA's Climate Data Online service where GHCN climate files can be retrieved in either US or SI units. (#72)

8. An additional validation check was added to the user-supplied Initial Deficit value for Green-Ampt infiltration.

9. The conversion of runon flow into an equivalent ponded depth
   for Curve Number infiltration was fixed.

10. A new parameter was added to Rain Barrel LIDs indicating whether the rain barrel is covered or not.

11. The effect that the Impervious Surface Fraction parameter for Permeable Pavement LID has on the pavement layer's effective permeability is now accounted for.

12. The values of water depth in a Permeable Pavement LID written to the detailed LID report file are now expressed as inches (or mm) instead of feet.

13. The math expression parser was modified to allow exponents to be expressions instead of just constant numerical values.

14. The way in which average flow is computed was changed for the time-step-average reporting option. (#71)

15. The total reporting time value used to compute several statistics in the summary results tables was corrected.

16. Shell sort replaces insertion sort for sorting event periods.

17. The number of open files that SWMM can access was increased to 8192. (#68)

18. The command line executable now supports binary output files larger than 2 Gbytes.

19. A number of new functions were added to the SWMM 5 API.

swmm-solver

Build 5.1.15 (July 2020)

Engine Updates:

1. A mix of infiltration methods can now be used within a project.

2. Monthly adjustments to depression storage are now applied only to
   the pervious area of subcatchments instead of to both pervious and
   impervious areas.

3. The Status Report now includes a grouped frequency table of the
   variable routing time steps used during a simulation.

4. An error in the average summary statistics reported for projects
   with a reporting start date later than the simulation start date
   was fixed.

5. A fatal error is now issued if a storage node's area curve produces
   a negative volume when extrapolated to the node's full depth.

6. A pollutant mass balance error occurring when very shallow storage
   units lost all inflow to flooding was fixed.

7. Conduit evaporation and seepage losses are now applied directly to
   the conduit's flow rate instead of just to the downstream node's
   inflow to reduce water quality mass balance errors.

8. Spurious values appearing for Final Water Table and Upper Mositure
   Content in the Groundwater Summary Results Table for completely
   impervious subcatchments were corrected.

swmm-solver

Build 5.1.14 (Feb 2020)

Engine Updates:

1. Fixed a refactoring bug that produced incorrect rainfall when the same
   time series was used by one rain gage assigned to a RDII Unit Hydrograph
   and also by another gage assigned to a subcatchment. (#20)

2. Fixed skipping the first rain gage in a project when checking
   if two gages have the same station ID but use different data files. (#13)

3. Fixed a program crash when running projects with LID units but no
   subcatchments. (#14)

4. Fixed having LID underdrain pollutant loads incorrectly added to the
   mass balance totals.

5. Fixed the program from hanging when an LID unit sent its outflow back
   onto the pervious area of its own subcatchment. (#10)

6. Fixed a failure to re-initialize layer volumes as each LID unit is
   evaluated (which could cause incorrect results for certain
   combinations of LID units).

7. Fixed street sweeping being ignored when the sweeping period
   began with a higher day of the year than the end of the period. (#11)

8. Fixed incorrect adjustments being made for conduit evaporation and
   seepage losses under dynamic wave flow routing. (#27)

9. Fixed having soil moisture deficit recovery be ignored for Green-Ampt
   exfiltration from storage units. (#19)

10. Fixed having node/link ID names be mistaken for option keywords
    in the [REPORT] section of an input file. (#17)

11. Fixed a possible program crash when using the option to report average
    values within each reporting time interval instead of point values.

swmm-solver

Build 5.1.13 (Aug 2018)

Engine Updates:

1. A subcatchment's depression storage depth, its pervious surface roughness
   (Mannings n) and its hydraulic conductivity can now be adjusted on a
   monthly basis by assigning monthly time patterns to these properties.
   For conductivity, a subcatchment-specific adjustment pattern will
   override any project-wide set of climate adjustment factors.

2. LID controls can now treat a designated portion of a subcatchment’s
   pervious area runoff (previously they could only treat impervious area
   runoff).

3. Permeable pavement LID units subjected to clogging over time can now
   have their permeability only partly restored at periodic time
   intervals

4. The following options were added to control flow out of LID units
   through their underdrains:

   • A storage layer water depth above which a closed drain automatically
     opens.
   • A storage layer water depth below which an open drain automatically
     closes.
   • A control curve that specifies how the nominal drain flow rate is
     adjusted as a function of the head seen by the drain.

5. Pollutant removal percentages can now be assigned to LID processes that
   have underdrains. The removals apply to flow leaving the unit through the
   drain and not to any surface overflow from the unit.

6. The Subcatchment Runoff Summary Report now includes both pervious and
   impervious total runoff volumes (prior to any LID treatment) for each
   subcatchment.

7. A choice of method used to handle surcharging has been added to the list
   of Dynamic Wave options. The EXTRAN method continues to use the traditional
   Surcharge Algorithm to update the head at surcharged nodes. The new SLOT
   option attaches a Preissmann Slot to closed conduits flowing more than 98.5%
   full that eliminates the need to switch to the Surcharge Algorithm for
   surcharged nodes.

8. A closed vessel can now be modeled as a storage unit node that is allowed
   to pressurize up to a designated Surcharge Depth value. If this depth is 0
   then the unit is modeled as before as an open vessel.

9. A weir's discharge coefficient can now be allowed to vary with head across
   the weir by assigning it a Weir Curve (see Weir Properties). Weir curves
   tabulate coefficient values at specific head levels.

10. When the upstream offset of a regulator link is below the invert of its
    downstream node it is now automatically raised only for Dynamic Wave flow
    routing with a warning message issued. For other flow routing choices only
    the warning message is issued and no automatic offset adjustment is made.

11. Users can now choose to set a periodic time step for control rule evaluation.
    If this step is 0 then rules are tested as before at every routing time step.

12. The option was added to have time series results for a project's nodes and
    links be reported as average values computed over a reporting time step
    instead of being interpolated point values at the end of the reporting time
    step.

13. The following bugs were fixed:

    • Unused rain gages are no longer examined when adjusting the wet runoff
      time step.
    • The surface inflow rate to a permeable pavement LID unit is not allowed
      to exceed the pavement’s permeability.
    • The Minimum Nodal Surface Area dynamic wave routing option was being used
      as surface area always available at a node instead of an amount available
      only when the surface area of the node's connecting links fell below it.
    • The top width of a full closed rectangular cross section shape is now set
      to 0 since it can no longer supply any surface area.
    • The ‘C’ parameter value for a Mitered Corrugated Metal Arch culvert was
      corrected.
    • An incorrect reporting of flow continuity error for systems with backflow
      through outfall nodes was fixed.