SWMM 5.1 Update History - Build 5.1.008 (04/02/2015)
SWMM 5.1 Update History ======================= -------------------------- Build 5.1.008 (04/02/2015) -------------------------- Engine Updates: New Features: ============= 1. Monthly adjustments for hydraulic conductivity used for rainfall infiltration and for exfiltration from storage nodes and conduits was added. 2. LID drains can now send their outflow to a different node or subcatchment than the parent subcatchment in which they were placed. 3. Conveyance system Outfall nodes now have the option to send their outflow onto a subcatchment, to simulate irrigation or complex LID treatment options. 4. A new LID practice, Rooftop Disconnection, has been added. It allows one to explicitly model roof runoff with an optional limit on the flow capacity of their downspouts. Disconnection is specified by setting the Return To Pervious Area field in the [LID_USAGE] section to 1. 5. An optional soil layer has been added to Permeable Pavement LIDs so that a sand filter or bedding layer beneath the pavement can be modeled. 6. Several new built-in variable names can now be used in custom groundwater flow equations for porosity, unsaturated hydraulic conductivity, infiltration rate, and percolation rate. See the Help file for more details. 7. A Groundwater Summary table has been added that reports several groundwater statistics for each subcatchment. 8. A new option, the Minimum Variable Time Step, was added that limits the smallest time step that can be computed under variable time stepping for dynamic wave flow routing. In previous releases it was fixed at 0.5 seconds which remains the default. The smallest value it can now have is 0.001 sec. 9. The dynamic wave routing procedure was parallelized to take advantage of multiple processors, making it run several times faster. A new option, THREADS, sets the number of parallel threads to use, where the default is 1. 10. A new column was added to the Node Depth Summary report table that shows the maximum depth recorded at the Reporting Time Step so it can be compared to the maximum depth attained over all routing time steps also shown in the table. 11. Control rule premises can now contain conditions that compare the values of a node or link variable at two different locations (e.g. IF NODE 123 HEAD > NODE 456 HEAD) and node volume was added as a condition clause variable. Improvements: ============= 12. When a subcatchment with LID controls receives runon from another source (e.g., a subcatchment, LID drain or outfall node) the runon is now distributed only across the non-LID area of the sub- catchment instead of the full area. If a single LID takes up the full subcatchment area then the runon is directed onto the LID. 13. Storage node HRT was added to the state variables saved in the Hot Start file. 14. The threshold value for reporting a non-zero runoff result was changed from 0.001 cfs to 0.001 inches/hr. 15. The calculation of overall flow routing mass balance was modified to account for cases where some flow streams, like total external inflow, are negative. 16. The "Surface Runoff" label in the Runoff Continuity Report was replaced with "Total Runoff" since the value reported consists of both surface runoff and LID drain flow. 17. The "Internal Outflow" label in the Flow Routing Continuity Report was replaced with "Flooding Losses" to improve clarity. 18. The pollutant washoff routines were moved to a new code module (surfqual.c) and revised to account for the reduction in pollutant load that results from runoff flow reduction by LID units. 19. Initial flows for Steady Flow routing are now ignored since they are not used in the routing calculation and the initial volume associated with them contributed to system mass balance error. 20. The various types of lateral inflows to conveyance system nodes are now evaluated at the date/time for the start of the routing time step instead of at the end of the time step. 21. The final runoff and routing time steps are adjusted to insure that the simulation's total duration is not exceeded. 22. When evaluating user-supplied math expressions, any NaN (Not a Number) result (caused by an underflow, overflow or divide by zero) is set to 0 so that the NaN doesn't propagate through subsequent calculations. Bug Fixes: ========== 23. The evaporation rates read from a time series would only change when a new day was reached (even though values at more frequent intervals were present) and could cause a run to stop pre- maturely in some rare cases. 24. The runoff read from a Hot Start file should have been assigned to a subcatchment's newRunoff property, not to oldRunoff. 25. An indexing bug that caused Hot Start files with snowmelt parameters to be read incorrectly was fixed. 26. The setting for a non-conduit link read from a Hot Start file was not being used to initialize the link. 27. A bug in adjusting snowmelt for snow covered area derived from an areal depletion curve was fixed. 28. Snowmelt should not have been included in the total precipitation reported for a subcatchment since the snowfall which produced it was already accounted for. 29. When computing a flow rate through the Drainage Mat of a Green Roof LID unit, the mat's void ratio was being applied to the water depth instead of to the mat's area. 30. The state of LID controls was not being considered when choosing to use the wet or dry runoff time step which sometimes lead to excessive LID continuity errors. 31. A re-factoring bug that left reporting time in minutes instead of hours in the detailed LID results file was fixed and results are now written to the file at each runoff time step where the state of the LID unit changes. 32. Failure to initialize groundwater evaporation loss to 0 was causing problems with the reported groundwater mass balance for subcatchments that had no pervious area. 33. Excessive continuity errors for systems having conduits with large seepage rates was fixed. 34. Pollutant loss through seepage in conduits and storage nodes was not being included in the mass balance calculations. 35. Concentrations in conduits and storage nodes were not being increased to account for loss of water volume when evaporation was occurring. 36. Premature exiting of the routine that checks for capacity limited links whenever a non-conduit link was encountered was fixed. 37. A bug in identifying the percent of time that a conduit has either end full was fixed. 38. A re-factoring bug that prevented surcharged weirs (see Update 5 for 5.1.007) from passing any flow was fixed. 39. A bug in evaluating recursive calls to nodal water quality treatment functions was fixed. GUI Updates: 1. The missing July - December column labels were restored on both the evaporation and wind speed tables in the Climatology Editor. 2. The label "Surface Water Height (Hsw)" in the Groundwater Flow Editor was changed to "Surface Water Depth" to make clear that it is the depth of water at the receiving node and not the height of water above the aquifer bottom (or Hsw as shown in the dialog's diagram). 3. The label "Channel Bottom Height (Hcb)" also in the Groundwater Flow Editor was changed to "Threshold Water Table Elev." to make clear that it is an elevation and not a height above the aquifer bottom (as Hcb is in the dialog's diagram). 4. A Groundwater Summary table was added to the form that displays summary results tables. 5. Groundwater upper zone soil moisture and node lateral inflow are now included in the abridged Hot Start file that the GUI can produce (using the File | Export | Hot Start File command). 6. The column labels in the various sections of the SWMM input file generated by the GUI were modified to better match the labels used to describe the input file format in Appendix D of the Users Manual. 7. A "Route To" field was added to the Outfall Node property editor to accommodate the new option of allowing outfall nodes to discharge onto a subcatchment. 8. The Dynamic Wave page of the Simulation Options dialog was modified to include the new Minimum Routing Time Step option and the new Number of Threads option. 9. The LID Control Editor was updated to include the new Rooftop Disconnection LID practice and the option to add a soil layer to the Permeable Pavement practice. 10. A Drain Outlet field was added to the LID Usage Editor. 11. The conduit Cross Section Editor dialog was enhanced to display a selectable list of standard size codes and their dimensions for elliptical and arch pipes. 12. Custom changes made to the Map's Legends are now saved with the rest of a project's settings in its .ini file. 13. Word wrapping was added to the Title/Notes display in the Project Browser to make the contents easier to read. 14. Modal dialog message windows now appear centered over the form that generates them instead of in the middle of the full display screen. 15. The style of all dropdown list boxes was changed to make them more visually appealing.