7. Chapter 7: Debugging and Trouble Shooting the Data Files

Troubleshooting Guidelines

Data Errors

Data input errors may result in the automatic termination of a simulation run along with a Fortran error message. The error message will report a ‘Unit’ number that is associated with the FLO-2D file that contains the error. The files are listed in Table 4.1, Table 7.1, and Table 7.2.

Table 7.1 List of Misc Files and Unit Numbers

Unit No.	File Name	Unit No.	File Name
47	ARF.BAC	398	MANNINGS_N.BAC
260	BREACH.BAC	2902	MANNINGS_N_RES.BAC
387	BUILDING_COLLAPSE.BAC	48	MULT.BAC
46	CHAN.BAC	51	OUTFLOW.BAC
40	CONT.BAC	42	RAIN.BAC
35	EVAPOR.BAC	1569	SDCLOGGING.BAC
41	FPLAIN.BAC	49	SED.BAC
121	FPXSEC.BAC	53	STREET.BAC
1610	GUTTER.BAC	1567	SWMMFLO.BAC
69	HYSTRUC.BAC	1564	SWMMOUTF.BAC
43	INFIL.BAC	29	TOLER.BAC
44	INFLOW.BAC	397	TOPO.BAC
58	LEVEE.BAC	2901	TOPO_RES.BAC

Troubleshooting: Is the flood simulation running OK?

There are several indicators to help you identify modeling problems. The most important one is volume conservation. The FLO-2D results should be reviewed for volume conservation, surging, timestep decrements, and roughness adjustments with limiting Froude numbers.

Volume Conservation

Any hydraulics model that does not report on volume conservation should be suspected of generating or losing volume. A review of the SUMMARY. OUT file will identify any volume conservation problems. This file will display the time when the volume conservation error began to appear during the simulation. Typically a volume conservation error greater 0.001 percent is an indication that the model could be improved. The file CHVOLUME. OUT will indicate if the volume conservation error occurred in the channel routing instead of the overland flow component. Components should be switched ‘off’ one at a time and the model simulation run again until the volume conservation problem disappears. This will identify which component is causing the difficulty. Some volume conservation problems may be eliminated by slowing the model down (decreasing the timesteps) using the numerical stability criteria. Most volume conservation problems are an indication of data errors.

Surging

It is possible for volume to be conserved during a flood simulation and still have numerical surging. Numerical surging is the result of a mismatch between flow area, slope and roughness. It can cause an over-steepening of the floodwave identified by spikes in the output hydrographs. Channel surging can be identified by discharge spikes in the CHANMAX.OUT file or in the HYDROG program plotted hydrographs. Predicted high maximum velocities indicate surging. To identify floodplain surging, review the maximum velocities in the MAXPLOT or Mapper post-processor program. You can also review the VELTIMEC.OUT (channel) or VELTIMEFP.OUT (floodplain) files for unreasonable maximum velocities. Surging can be reduced or eliminated by adjusting (lowering) the stability criteria (COURANT or DEPTOLFP in TOLER.DAT) thus decreasing the timesteps. If decreasing the timesteps fails to eliminate the surging, then individual grid element topography, slope or roughness should be adjusted. This can be accomplished in the FLO-2D Plugin for floodplain flow. For channel flow, the PROFILES program can be used to make adjustments. Increasing the flow roughness will generally reduce or eliminate flow surging. For channel surging, abrupt transitions in flow areas between contiguous channel elements should be avoided. Setting a lower limiting Froude number for a channel reach may also help to identify the problem.

Sticky Grid Elements

When the flood simulation is running slowly, the TIME.OUT file can be reviewed to determine which grid elements are causing the most timestep decreases (‘sticky elements’). TIME.OUT lists the top twenty floodplain, channel or street elements that caused the model to slow down. The file also lists whether the timestep decreases occur with the percent change in depth, Courant criteria or dynamic wave stability criteria. Adjustments can be made in the stability criteria to more equably distribute the timestep decreases. The model is designed to advance and decrement timesteps, so there have to be grid elements listed in the TIME.OUT file. If one or two grid elements have significantly more timestep decreases than the other elements listed in the file, the attributes of the ‘sticky’ grid elements such as topography, slope or roughness should be adjusted. The goal is to make the model run as fast as possible while avoiding numerical surging.

If a floodplain element is causing most of the timestep decreases, check the SURFAREA.OUT file to determine how much surface area is left in the floodplain element for flood storage. If the floodplain element contains a channel bank, there may be very little surface area left for flood storage. This will cause the model run slowly with exchanges the flow between the channel and floodplain. To fix this problem:

• Remove other components from the channel bank element including streets or ARF values.

• Shorten the channel length (XLEN in CHAN.DAT). This will increase the surface area in the channel bank floodplain elements.

• Decrease the channel cross-section width in the PROFILES program.

Limiting Froude Numbers

There is a unique relationship between floodwave celerity and average flow velocity described by the Froude number that should not be violated during numerical flood routing. This is a physical relationship between the kinematic and gravitation forces. To use the limiting Froude number, estimate a reasonaclsble maximum Froude number for your flood simulation and assign the value to either FROUDL (floodplain), FROUDC (channels) or STRFNO (streets) variables. When the computed Froude number exceeds the limiting Froude number, the n-value is increased by a small value (~ 0.001) for the next timestep. This change in grid element n-value helps to create a better match between the slope, flow area and n-value during the simulation. When the limiting Froude number is no longer exceeded, the n-value is gradually decreased to the original value. The changes in the n-values during the simulation are reported in the ROUGH.OUT file. For the next FLO-2D simulation, grid element n-value adjustments can be made using the n-values reported in ROUGH.OUT. The maximum n-values are also reported in MANNINGS_M.RGH, CHAN.RGH and STREET.RGH files that are created at the end of a simulation. These (*.RGH) files can then be renamed to data input files (*.DAT) for the next flood simulation (e.g. MANNINGS_N.RGH = MANNINGS_N.DAT).

Reviewing the results

FLO-2D results include the maximum area of inundation as displayed by the maximum flow depth, temporal and spatial hydraulic results, channel or floodplain cross-section hydrographs and peak discharges. The Mapper++ program can used to review maximum flow depths, water surface elevations or velocities. The results can be plotted as either line contours or shaded contours in Mapper++. Look for any maximum velocities or flow depths that are unreasonable. This may be an indication of numerical surging.

The FLO-2D flood simulation can be terminated at any time during the run by clicking Exit on the toolbar. The simulation will terminate after the current output interval is completed and the output files are generated and saved. This enables the user to check if the flood simulation is running poorly (e.g. too slow or not conserving volume) and the simulation can be stopped without losing the opportunity to review the output data.

Make some adjustments

The following data file adjustments may improve the simulation and speed up the model:

Spatial Variation of n-values

The most common cause of numerical surging is underestimated n-values. Typical n-values represent steady, uniform flow. Spatial variation of n-values will affect the floodwave progression (travel time) and reduce surging, but may not significantly impact the area of inundation (especially for longer flood durations). Focus on the critical part of the project area when adjusting n-values and review TIME.OUT and ROUGH.OUT to complete the n-value revisions.

Edit Topography

The interpolation of DTM points to assign elevations to grid elements is not perfect even when the FLO-2D Plugin filters are applied. It may be necessary to adjust some floodplain grid element elevations when you review the results. MAXPLOT and Mapper++ can be used to locate grid elements with unreasonable flow depths that may constitute inappropriate depressions. Floodplain depressions can sometimes occur along a river channel if too many floodplain DTM points located within the channel.

Floodplain Surface Area Reduction

The distribution of flood storage on the grid system can be influenced by assigning area reduction factors (ARF’s) to represent loss of storage (i.e. buildings). For large flood events, the assignment of individual grid element ARF values will usually have minor impact on the area of inundation. For local flooding detail, individual grid element ARF assignments may be justified.

Channel Cross-Section Adjustments

Typically a surveyed cross-section will represent five to ten channel elements. Selecting a cross-section to represent transitions between wide and narrow cross-sections requires engineering judgment. Use the PROFILES program to interpolate the transition between surveyed cross-sections.

Channel Slope Adjustments

Adverse channel slopes can be simulated by FLO-2D. Smoothing out an irregular slope condition over several channel elements to represent reach average slope conditions may speed up the simulation. Cross-sections with scour holes can result in local adverse slopes that misrepresent the average reach conditions. Review the channel slope in PROFILES.

Street Flow

High street velocities may cause numerical surging and slow the simulation down. Assign reasonable limiting street Froude numbers to adjust the street n-values.

Model Calibration and Replication of Flood Events

Estimating flood hydrology (both rainfall and flood hydrographs) can be difficult when replicating historical floods. To match measured flood stages, high water marks or channel discharges, first determine a reasonable estimate of the flood volume, then concentrate on the model details such as n-values, ARF’s and street flow. Flood volume is more important to flood routing than the peak discharge.

Trouble Shooting Technique

When undertaking a new FLO-2D flood simulation, start simple and progressively build in model component detail. After the required data files have been prepared, run a basic overland flood simulation. Review the results. If any issues arise consult the troubleshooting tips found in this chapter. Table 7.2 lists some common data errors.

To debug the data files after a FLO-2D simulation, begin by reviewing the ERROR.CHK file. All the data errors recognized by the model are reported in this file. FLO-2D has an extensive data error and warning message system and the messages are reported in ERROR.CHK as data inconsistencies are encountered. One of the most common errors is missing data that will invoke an end-of-file error statement to the screen. This error occurs when the model is searching for more data than is in the data file. Another common error is to activate a component or process switch without preparing the required data file. For example, an error will occur if the component switch ICHANNEL = 1 in the CONT.DAT file, but the data file CHAN.DAT is not available.

One data error that is difficult to locate is the array allocation violation where the array index number becomes zero or larger than the assigned value. For example, there may be missing sediment concentrations in INFLOW.DAT for a mudflow simulation. This made a code error where a variable is not initialized to zero. When this type of error is encountered, the FLO-2D model is terminated with a FORTRAN error message without indicating the file location or line entry of the error. To locate the data error, simplify the simulation and turn off all of the components and turn them back on one at time until the error occurs again. Reset simulation time to the model time just after the error occurred to reduce time to debug the model. If attempts to debug an error are ineffective, send a zipped copy of the data files to FLO-2D via this Contact Form along with brief description of the problem.

The user can create a set of backup data files to debug the model. Set IBACKUP = 1 in the CONT.DAT file. These backup files replicate the data files and will indicate if the computer is reading the data files correctly. The backup file should be identical to the original data file except for spacing. If the program terminates before reaching the first output interval timestep, there is probably an error in the data files. Start by checking the *.BAC files one by one. If one of the files is not complete, this may be the location of the data error.

Review the following files to analyze volume conservation problems: SUMMARY. OUT, CHVOLUME.OUT, CHANMAX.OUT, TIME.OUT, BASE.OUT, ROUGH.OUT, CHANNEL.CHK, and SURFAREA.OUT. See the ‘Pocket Guide’ for further troubleshooting tips involving volume conservation, sticky grid elements listed in the TIME.OUT file, and numerical surging. The instructional comments at the end of each data file description in this manual contains a number of guidelines to assist the user in creating or checking the data files.

List of Common Data Errors

A list of the most common errors associated with running FLO-2D is presented below and a table for troubleshooting runtime errors follows the list. Whenever an error is encountered, refer to the ERROR.CHK file first. All of the *.CHK files are listed in Table 7.3. The file descriptions can be referenced in Chapter 5.

Table 7.2 List of Common Data Errors

Table 7. 2 List of Common Data Errors

Missing data entries. Insufficient data was provided to the model.

Switches were activated without the corresponding data or files(for ex- ample, see MUD, ISED, etc., in the CONT.DAT file).

There was missing or additional lines in a data file when switch is activated. Observe the *** Notes: *** in the file descriptions.

Percentages were expressed as a number instead of a decimal. See the description of XCONC in CONT.DAT or the HP(I,J,3) variable in INFLOW.DAT.

The IDEPLT grid element was improperly assigned in INFLOW.DAT for the graphics mode.

Channel infiltration switch INFCHAN was not ‘turned on’ in the INFIL.DAT file.

Either one or both of channel and floodplain outflow elements were not assigned for a given grid element.

The street width exceeded the grid element width.

The array size limitation for a variable was exceeded.

The available floodplain surface area was exceeded by assigning channels, streets, ARF’s and/or multiple channels with too much surface area. Review the SURFAREA.OUT.

The rainfall variable R_DISTRIB data was entered as total cumulative rainfall instead of the percentage of the total rainfall (range0.0 to 1.0).

The ISEDN switch for channel sediment transport was not ‘turned on’ in the CHAN.DAT file for the channel segment.

Runtime Errors

If the simulation stops before reaching the prescribed simulation time, review the output files for diagnostic information:

• If the program ends with a Fortran Error, screenshot the error message. It may reveal the file location where the error occurred.

• Review the *.CHK files for potential data errors.

• Review the channel check files for potential errors.

7.1. Volume Conservation Errors

Most volume conservation and numerical stability problems are associated with channel flow. When constructing a channel system, it is often necessary to fabricate cross-section geometry, estimate roughness or adjust channel bed slopes. Mismatched channel morphology parameters with an appropriate roughness are the primary source of numerical stability problems. To compute smoother hydraulics between two channel grid elements, adjust the bed slope, cross-section flow area or roughness values. Try to avoid abrupt changes in cross-sections geometry from one channel element to another. The channel flow area for a natural channel (not a concrete rectangular or trapezoidal channel geometry) should make a gradual transition from a wide, shallow cross-section to a narrow deep cross-section. An actual cross-section transition may occur over several channel grid elements. Adjust the channel geometry so that the maximum change in flow area between channel elements is less than 25%. To address channel problems, consider the following measures:

• Increase the roughness in wide, shallow cross-sections and decrease the roughness in narrow deep channel grid elements.

• Reduce the difference between the cross-section areas. Avoid abrupt cross-section transitions between channel elements. Adjust the channel cross-section geometry in the PROFILES. Use PROFILES to re-interpolate between surveyed cross-sections.

• Review and adjust the bed slope with the PROFILES program. Adverse bed slopes are OK but adverse spikes and dips are not.

• Select a longer channel length within the channel grid element.

7.2. One Drive Sync

Running simulations on projects that are stored on a directory that is synced to One Drive may result in a simulation crash. Small projects that run quickly and do not have long intervals between data output might be OK but it is a poor modeling practice to run projects on paths like the Desktop or Documents folder that will always sync to Microsoft One Drive. Not only does this practice risk a simulation crash, it also results in overall sluggish computational behavior. Forcing a memory analysis and sync places a unnecessary burden on computer processors. If simulations take more than 12 hours, consider moving projects to a directory that is not syncing to One Drive.

7.3. Anti-Virus Software

This program are important but allowing them to continually scan for viruses or malware will add a processing burden to the computer. If a simulation takes more than 12 hours, consider running it on a computer that is dedicated to modeling that can be isolated with a firewall that limits web traffic so that anti-virus software scans can be limited or turned off while the simulation is running.

7.4. External Drives

Running simulations on external drives may result in a crash due to drive connectivity errors. It will also slow simulations since the data transfer at runtime is happening over the network path that connects the computer to the drive. External drives may also have protections so that executables cannot write data to the drive. It is better to run simulations on the local computer.

7.5. Servers and Virtual Computers

Running simulations on servers or virtual computers is relatively straight forward and easy. For a Virtual Computer, simply set up the computer the same way a normal installation is performed. FLO-2D and QGIS can be installed on a Virtual Computer. Use it just like a regular computer.

Servers can be set up for running FLO-2D models but it is not necessary to install FLO-2D in order to run simulations. A program like Docker can be used to build, deploy, and optimize server configurations. Get help from an IT professional and FLO-2D staff to explore this option. It should be noted that for FLO-2D no server system can outperform a high performance desktop computer running AMD high performance processors.

Table 7.3 List of *.CHK Files and Unit Numbers

Unit No.	File Name	Unit No.	File Name
7	ERROR.CHK	1234	MODFLOW_ERROR.CHK
56	CHANNEL.CHK	1577	UNDERGROUNDOUTFALLS.CHK
86	CHANBANKEL.CHK	1578	RainCell.CHK
194	BATCH.CHK	1580	HDF5_Error.CHK
333	NOSHOW.CHK	1590	RainOneCell.CHK
1571	STORMDRAIN_ERROR.CHK	8871	ARF_ADJUSTMENT.CHK
991	DEBUG.CHK	6669	HYDRAULIC STRUCTURE_SHALLOW FLOW WARNING.CHK
6670	6670 HYDRAULIC STRUCTURE_TAILWATER WARNING.CHK	6671	HYDRAULIC STRUCTURE_HEADWATER WARNING.CHK
6673	HYDRAULIC STRUCTURE_HEADWATER WARNING.CHK

Debugging Errors

In addition to the following troubleshooting guide, refer to the ‘Getting Started Guidelines’ at the begin of this manual and the Pocket Guide to assist in debugging runtime errors.

Program will not run:

• Data errors: Turn off the component switches until the model runs.

• The executable program was damaged: Reload the program or contact technical support.

• The model is not properly licensed: Contact technical support.

Program stops

The model run is terminated before the first timestep or after a few timesteps with data file error indicated on the screen or in ERROR.CHK:

• Review the ERROR.CHK file or the data file identified by the program error message.

• Review the backup file (*.BAC).

• Review the List of Common Data Errors.

Program stops

The model run is terminated after several timesteps indicating a numerical stability error. The grid element causing the stability error is listed on the screen instability dialog box or at the end of the BASE.OUT file.

Stability criteria were not met.

Review and revise the elevation and roughness data for the indicated grid element. The ROUGH.OUT and TIME.OUT files will help to locate the problem grid element. Check the contiguous grid elements to the problem element in the 8 directions as the problem may be with the neighbor element.

Volume conservation

The volume conservation may indicate either a loss or gain of volume. A review of the SUMMARY.OUT and CHVOLUME.OUT will reveal if the volume conservation error is in the channel or on the floodplain. Volume conservation problems are indication of data error.

Discharge surging

Numerical surging, which involves alternating low and high discharges, is typically associated with channel flow. Floodplain surging can also occur but is less common. Maximum floodplain velocities should be reviewed in the MAXPLOT, VELTIMEC.OUT, and VELTIMEFP.OUT files. Any unreasonable maximum velocities identified should be addressed.

Other files that may indicate numerical surging include CHANMAX. OUT, HYCHAN.OUT, CHANSTABILITY.OUT, TIME.OUT, and ROUGH.OUT.

Hydrograph plots generated in the HYDROG program may show spikes that suggest surging. It is important to note that surging can occur even when overall volume conservation remains acceptable.

Supercritical flow

Supercritical flow is not necessary a problem, but its occurrence should be limited to conditions where it is expected such as in streets, concrete channels or steep bedrock watersheds. Supercritical flow on alluvial surfaces should be avoided.

Numerical Instability:

The channel surging may be related to numerical instability, abrupt changes in channel geometry, inappropriate slopes, supercritical flow or variable mudflow sediment concentrations. Mismatched slope, flow area and n-values are the most common causes of channel instability. A combination of revisions may improve numerical instability.

• Abrupt changes in slope or severe adverse slope may cause instability. Use the PROFILES program to fix irregular bed slope conditions.

• Review the cross-section flow areas over several channel elements in PROFILES. Eliminate any abrupt changes in cross-section areas between channel elements. If the surging occurs at low flows, review only the bottom portion of the cross-section not the bankfull conditions.

• Decrease the channel Courant number in the TOLER.DAT file. Decrease the Courant number in 0.1 increments until a reasonable lower limit of 0.2 is reached.

• Insufficient floodplain area. Small floodplain surface areas can exacerbate unsteady flow. Review SURFAREA.OUT and increase the available grid element surface area for flood storage.

• Increase the n-values for the grid elements in the vicinity of the surging flow.

• Adjust the floodplain grid element elevations around the problem element.

• Increase the channel length within the grid element.

• The hydraulic structure discharge rating curve or table may be poorly matched with the upstream or downstream channel hydraulics. Review the hydraulic structure rating curve or table and compare the discharge values to those found in the HYCHAN.OUT file for that particular channel element or the next one upstream.

Unexpected supercritical flow on alluvial surfaces:

• Adjust the limiting Froude number using the FROUDL variable in the CONT.DAT file or the FROUDC variable in the CHAN.DAT.

• Increase the floodplain or channel roughness values.

• Modify the slope. The grid elevations assigned by the FLO-2D Plugin may not be representative of the field condition. Change the grid element elevations to make the channel or floodplain slope more uniform.

Variable mudflow sediment concentration:

• Review the sediment concentration in the inflow hydrographs in the INFLOW.DAT file.

• The relationships for viscosity and yield stress should fall with the research data presented in the reference manual.

FLO-2D simulation runs slow

Review the TIME.OUT file to identify the elements that have caused most of the timestep reductions. Small timesteps are the result of the model continually exceeding the numerical stability criteria for a small group of grid elements. The change in flow depth for a timestep may be too large. One of primary reasons for a slow flood simulation is that the relationship between the discharge flux and grid element surface area is poor. The rate of change in the discharge may be too high for the selected grid element size. Increasing the grid element size is the best way to fix a very slow model.

Other solutions may include:

• Adjust the channel geometry in transition reaches.

• Create a more uniform channel or floodplain slope.

• Revise the roughness values or limit the supercritical flow.

• Reduce the channel width, street width, ARF values or other parameters to increase the floodplain surface area. Review the SURFAREA.OUT file.

• Check for updates. FLOPRO.EXE updates.

• Increase the grid element size (a last resort).

The inflow hydrograph does not plot in the graphics display

• No hydrograph is associated with the IDEPLT variable.

• The hydrograph duration is too long. Reduce the hydrograph length.

• The rainfall duration is too long. Reduce the rainfall time.

• Inappropriate peak discharge or total rainfall values distort the scale for hydrograph plot.

Program stops. Excessive flow depths

If flow depths are excessive, then ponding or surging may be occurring.

• Identify the problem element in MAXPLOT or in the end of the BASE.OUT file.

• Check TIME.OUT to determine if the problem element is also causing the model to run slowly.

• Check the elevation of the problem grid element in the TOPO. DAT or in the FLO-2D Plugin.

• If the depressed element is a gravel pit or some other feature, increase the n-value to decrease the velocity (vertical overfall velocity) into the pit.

Erratic discharge in the channel elements.

A review of plotted hydrographs in HYDROG or an examination of the CHANMAX.OUT or HYCHAN.OUT files will reveal if the flow discharge between contiguous channel elements is surging with spikes when a consistent rise or fall of the downstream discharge is expected.

Channel surging can be natural phenomena. Rivers can rise and fall over a few tenths of a foot in matter of seconds in reaches that are expanding and contracting causing rapidly variable storage. During high flow in a large river, the variation in discharge associated with stage change on the order of ~ 0.2 ft can be 1,000 cfs or more. Review the numerical surging troubleshooting. If the channel surging is severe, the two conditions to review are:

• Review the channel confluence and make the confluence pairs are properly assigned. See the CONFLUENCE.OUT file.

• The channel grid elements in the CHAN.DAT file may be mis- identified.

Erratic flow in the floodplain grid elements.

Erratic flow in the floodplain grid elements is usually the result of errors in the TOPO.DAT file. This type of error generally occurs when the user edits the TOPO.DAT file manually and adds, subtracts or moves grid elements around. Virtually all erratic flow conditions on the floodplain can be corrected by revisions either to n-values or elevations in the FLO-2D Plugin.

Channel extends through another channel element.

The right channel bank assignments are automated in the FLO-2D Plugin. Multiple left bank elements can be assigned to the same right bank on a river bend. If a channel extends through a right bank element, the model will generate an error message reported in ERROR.CHK file.

The channel bank elements can be viewed in the FLO-2D Plugin. If there is a problem with the channel bank alignment, simply revised the right bank element. The right bank element can be any grid element if it does not cross another connecting channel bank line.

Program stops; identifying one or more grid elements with too little floodplain surface.

The model will generate a message in ERROR.CHK if the channel right bank has is too little surface storage area on the floodplain portion of the element. If this problem occurs and the floodplain surface is less than 5%, then there are several solutions:

• Reduce the ARF value, multiple channel area or street area.

• The channel area can be reduced by decreasing the XLEN variable or top width, which is a function of the channel in the natural channels, the side slopes, or the bottom width in the trapezoidal cross-section or the width in the rectangular cross-section.

• As a last resort the grid element size can be increased, but this requires the re-generation of the grid system.

CADPTS.DAT error

If errors are reported in this file, delete CADPTS.DAT, FPLAIN.DAT, and NEIGHBORS.DAT run the model again. The FLOPRO.EXE will rewrite this file.

Debug Output Tables

The DEBUG.OUT file is created when the user runs the model in Debug model via the QGIS Plugin. The error codes in Tables 7.4, 7.5, and 7.6 are the codes used in the Debug system. They help identify data errors and data conflicts. These files are generated as part of the preliminary data checks. These error checks do not include any simulation results. Table 7.5 and 7.6 offer basic corrective actions for the errors.

Table 7.4 ERROR CODE CATEGORIES

Error Code	Error Category
100	Switches, Control Variables, Version
200	Boundary, Coordinate, Floodplain, Elevation
300	Stability Criteria
400	TOL
500	Roughness
600	Rainfall
700	Infiltration
800	Inflow, Outflow
1000	Channel
2000	Hydraulic Structures
3000	Streets, ARF/WRF
4000	Storm Drain
5000	Cross-Sections
6000	Sediment, Mud
7000	Levees
8000	Multiple Channels

Table 7.5 BASIC ERROR CODES

Code	Reason	Solution
100	Versions of the FLO-2D Pro and Storm Drain are Different. Please Check FLO-2D Build and Update Vc2005-Con.Dll	Review engine file dates and flopro.exe and vc2005con.dll. Make sure the file dates correspond to builds that are the same. This may require Technical Support.
100	Floodway Switch = 1,Set Encroach in CONT.DAT	To run a floodway simulation, set Floodway Switch = 1 and set the Encroach variable in CONT.DAT. NOPRTC is a switch. The positions are 0, 1 or 2.
100	Set NOPRTC to Only 0, 1, or 2 in CONT.DAT	NOPRTC is a switch. The positions are 0, 1 or 2.
100	For Graphical Display (Lgplot=2),Graptim must be Greater Than 0	The variable Graphtim is missing in CONT.DAT.
100	Variable Xconc Exceeds 1	The sediment concentration cannot be greater than 1.
100	Variable Xarf is Less Than 0 or Greater Than 1	The Xarf variable must be a value between 0 and 1.
100	Variable Froudl Greater Than 9	The Froudl variable should not be greater than 1.
100	Variable Noprtfp is a Switch,Use Only 0,1,2 or 3	NOPRTFP is a switch. The positions are 0, 1 or 2.
100	Mudflow (Mud=1) and Conventional Sediment Transport (Ised=1) Cannot Be Modeled in the Same Simulation. Review CONT.DAT File	Set either MUD or ISED to 0.
100	Grid Element 1 Has No Neighbor Grid Elements,Check the CADPTS.DAT File	If grid element number 1 does not have a neighbor, it is dangling or the coordinates are wrong in TOPO.DAT. Check the location of the cell. Correct it by realigning the grid to the computational domain.
100	If Displaying the Flood Graphics - Lgplot = 2 in CONT.DAT - Then Ideplt must be Greater Than Zero in INFLOW.DAT	Set ideplt to an inflow grid element number in inflow.dat.
100	If Only Writing Text Output to Screen - No Flood Graphics Lgplot = 0 in CONT.DAT - Set Ideplt = 0 in INFLOW.DAT	For text mode, set lgplot = 0 and ideplt = 0.
100	Ideplt (INFLOW.DAT) must be an Inflow Node and the CONT.DAT Variable Lgplot must be Set to 1	Make sure Ideplt is a grid element listed in inflow.dat.
100	Total Simulation Time of the Model Exceeds the Hydrograph Duration	If the hydrograph ends before the simulation, make sure it is set to zero or the last discharge in the hydrograph will continue as steady flow.
100	If Ideplt is Listed As Inflow Node in the INFLOW.DAT File, Then Lgplot must be 0 or 1	Turn on the Lgplot and Graphtim to use Display Mode.
200	Grid Element Coordinates Exceed 1000000000. Reduce the Coordinate Values Before Proceeding	Check the coordinates in topo.dat.
200	Hydraulic Structure Channel Inflow must be a Channel Element	Reposition the structure node onto a left bank node.
200	Time-Stage Elements Have a Stage Assigned that Was Less Than the Floodplain or Channel Bed Elevation. Stage Was Reset to the Bed Elevation	Check the invert elevation of the structure, the grid element elevation or the head reference elevation.
200	If Ideplt is 0 in INFLOW.DAT and Irain is 0 in CONT.DAT, There is No Inflow to Be Plotted.	Either Set Lgplot = 0, Assign Ideplt an Inflow Hydrograph in INFLOW.DAT, Or Set Irain = 1 in CONT.DAT and Assign the RAIN.DAT File
300	A Channel/Street Courant Number is Required in TOLER.DAT	Set the correct Courant number.
300	If Istrflo in STREET.DAT is Set to 1,Then at Least One Inflow Node Must Have a Street in It	Check the STREET.DAT file.
400	Variable Tol Has an Inappropriate Value	Check the TOL value. It must be in a correct range.
400	Please Review If Tol = 0.05 Ft or 0.015 M With the Rainfall Abstraction	Check the TOL variable and the Initial Abstraction variable. The initial abstraction may be too high. See INFIL.DAT.
500	MANNINGS_N.DAT File Has a Mismatched Grid Element Number… Check the End of this File	The MANNINGS_N.DAT file might not be complete.
500	MANNINGS_N.DAT Files Does Not Exist. Create the File Before Proceeding	Export MANINGS_N.DAT again.
500	The Spatially Variable Shallown Value is Outside the Range 0.010 to 0.99	Check the SPATIALSHALLOWN.DAT file.
500	N-Value is Less Than 0 or Greater Than 1	Check the CONT.DAT file.
600	Line 2 in RAIN.DAT File Has to Be Reviewed For Spatially Variable Real Rainfall Adjustments (Irainarf=1) With Rainarf Values	Spatially variable data is missing. Check RAIN.DAT.
600	Rtt must be Greater Than 0	Check RAIN.DAT.
600	First Pair of the Rainfall Distribution Should Be 0.0.	Correct the first data pair of the rainfall distribution curve. Set the first data pair to 0.0 0.0.
600	Date and Time in Raincell.Dat Must Have this Format: 06-15-2003 14:00:00	Check RAINCELL.DAT.
700	Variable Infmethod Line 1 in the INFIL.DAT is Either Missing or Not Correctly Assigned	Check INFIL.DAT.
700	To Use the SCS Curve Number Method For Infiltration You Must Have Rainfall, Irain = 1 in CONT.DAT and RAIN.DAT File	Check RAIN.DAT.
700:	Variable Poros is Greater Than 1	Check INFIL.DAT.
700	Variable Sati or Satf is Greater Than 1	Check INFIL.DAT.
700	Variable Rtimpf Exceeds 1.0. Do Not Enter As a Percent Use a Fraction	Check INFIL.DAT.
700	Abstraction Exceeds the Total Rainfall (Impossible) For at Least One Grid Element and May Result in Volume Conservation Error	Check spatial abstraction variable in INFIL.DAT.
700	Initial Abstraction > Tol (Depression Storage). Consider (Not Required) Lowering the Tol Value or Adjusting the Ia Value	The TOL variable and IA variable can be summed to account for the initial abstraction.
800	There are Two Inflow Conditions Imposed at the Same Cell	A cell is listed twice in INFLOW.DAT. Check the file and remove one of the hydrographs.
800	This Grid Cell Has an Inflow and a Full ARF	Reposition the inflow node.
800	This Grid Cell Has an Inflow and a Partial ARF	Consider repositioning the inflow node.
800	The Following Cell Has an Inflow and a Hs	Reposition the inflow node or the hydraulic structure inlet node.
800	The Following Cell Has an Inflow Fp on a Channel Left Bank Element	Consider changing the inflow to channel inflow.
800	The Following Cell Has an Inflow Fp on a Channel Right Bank Element	Consider moving the inflow node to the left bank and changing it to a channel node.
800	There are an Inflow Conditions Imposed on a Levee Element	Check the levee Inflow condition. Make sure the inflow is on the correct side of the levee and make sure the cell elevation is set correctly.
800	This Grid Cell Has an Inflow on a Multiple Ch Element	Reposition the inflow node.
800	This Grid Cell Has an Inflow on a Multiple Ch Element	Reposition the inflow node.
800	There are Two Inflow Conditions Imposed at the Same Cell	A cell is listed twice in INFLOW.DAT. Check the file and remove one of the hydrographs.
800	The Following Cell Has an Inflow Ch on a Channel Right Bank Element	Move the inflow node to the left bank.
800	There are an Inflow Conditions Imposed on a Levee Element	Check the levee Inflow condition. Make sure the inflow is on the correct side of the levee and make sure the cell elevation is set correctly.
800	There are Two Outflow Conditions Imposed at the Same Cell	Remove the extra line in OUTFLOW.DAT.
800	The Following Cell Has a Channel Outflow on a Channel Right Bank Element	Move the outflow node left bank.
800	There are an Outflow Conditions Imposed on a Levee Element	Make sure the outflow node is on the correct side of the levee.
800	There are Two Outflow Conditions Imposed at the Same Cell	Move the outflow node left bank.
800	The Following Cell Has an Outflow (Fp) on a Channel Left Bank or Right Bank Element	It’s OK for n FP outflow node to be on a left bank but not a right bank.
800	There is an Outflow Conditions Imposed on a Levee Element	Make sure the outflow node is on the correct side of the levee.
800	There are Two Stage Time Relationships Imposed at the Same Cell	Remove one of the duplicate stage time conditions from OUTFLOW.DAT.
800	The Following Cell Has Stage Time Relationship on a Channel Right Bank Element:	Remove the outflow from the right bank.
800	There are a Stage Time Outflow Condition Imposed on a Levee Element	Make sure the outflow node is on the correct side of the levee.
800	There are a Stage Time Relationship Imposed on an Outflow Cell
800	There are a Floodplain Outflow and a Stage Time Relationship at the Same Cell
800	There are Two Outflow Conditions Imposed at the Same Cell	Delete one of the outflow nodes in OUTFLOW.DAT.
800	This Grid Cell Has an Outflow and a Full ARF	Delete the outflow node or the ARF.
800	This Grid Cell Has an Outflow and a Partial ARF	Delete the ARF.
800	The Following Cell Has an Outflow and a WRF	Delete the WRF.
800	This Grid Cell Has a Stage Time Relationship and a Full ARF	Delete the outflow node or the ARF.
800	This Grid Cell Has a Stage Time Relationship and a Partial ARF	Delete the ARF.
800	The Following Cell Has an Outflow and a WRF:	Delete the WRF.
800	This Grid Cell Has an Outflow and a Full ARF	Delete the outflow node or the ARF.
800	This Grid Cell Has an Outflow and a Partial ARF	Delete the ARF.
800	The Following Cell Has an Outflow and a WRF	Delete the WRF.
800	An Inflow Hydrograph Has Been Assigned to a Channel Element (C-Line in INFLOW.DAT) and There is No Channel Component (Ichannel = 0 in CONT.DAT)	Turn the channel switch on or reset the inflow node to floodplain.
800	First Pair of the Floodplain Hydrograph Should Be 0.0. to Interpolate the First Timestep	Set the first data pair to 0.0 0.0 in the INFLOW.DAT.
800	No Inflow Discharge Specified For the Inflow Element	Check INFLOW.DAT.
800	INFLOW.DAT Variable Ideplt must be an Inflow Node and an Inflow Node - Khin - Variable in INFLOW.DAT must be specified, CONT.DAT Variable Inplot must be Set to 1

Table 7.6 ADVANCED ERROR CODES

Code	Reason	Solution
1000	Inflow Fp on a Ch Interior Element	To run in display mode, set the graphics mode in CONT.DAT and the plotting hydrograph in INFLOW.DAT.
1000	Inflow Ch on a Ch Interior Element	Move inflow node or realign channel.
1000	Outflow Ch on a Ch Interior Element	Move inflow node or realign channel.
1000	Outflow Fp on a Ch Interior Element	Move outflow node or realign channel.
1000	Stage Time Relationship on a Ch Interior Element	Move outflow node or realign channel.
1000	Full ARF on a Ch Interior Element	Move outflow node or realign channel.
1000	Partial ARF on a Ch Interior Element	Delete ARF or realign channel.
1000	WRF on a Ch Interior Element	Delete ARF or realign channel.
1000	Hs inlet on a Ch Interior Element	Delete WRF or realign channel.
1000	Hs outlet on a Ch Interior Element	Move hydraulic structure or realign channel.
1000	Levee on a Ch Interior Element	Move hydraulic structure of realigning channel.
1000	Multiple Channel on a Channel Interior Element	Realign levee or realign channel.
1000	Channel Width is Greater Than the Element Width. Channel Left and Right Bank Elements Should Be Separated	Realign multiple channel. See reference manual.
1000	Channel Grid Element Will Require Separate Left and Right Bank Elements	Realign right bank. Extend right bank way from left bank.
1000	Channel Extension Exceeds the Grid System Boundary	Realign right bank.
1000	Channel Element Extends Into Interior of the Channel Element Instead Extend the Channel Into Another Bank Element	Realign right bank.
1000	Channel Element is Repeated in the CHAN.DAT File. Each Channel Element Should Only Be Listed Once	Eliminate one of the repeated channel elements. Tributary and Split flows should connect along adjacent banks.
1000	Channel Right Bank Elements Need Some Adjustment Due to the Channel Width. Set Right Bank Either Closer or Farther Away from the Left Bank Element	Realign right bank.
1000	Remaining Floodplain Surface Area on the Channel Bank Elements Needs to Be Larger For Left Bank Element	Extend right bank away from left bank.
1000	Data Error…Check the Channel Elements in the CHAN.DAT Files	Review CHAN.DAT. Load project in PROFILES.EXE to troubleshoot.
1000	Channel Extension For Grid Element Extends Into Another Channel Element	Realign right bank.
1000	Channel Confluence Element Does Not Have Enough Connections, or a Channel Segment is Beginning or Ending at a Main Channel Confluence Element	Review confluence elements. The tributary or split channel may not be close enough to the main channel banks.
1000	Channel Extends Past the Levee System, Please Review the CHANNEL. CHK File and Make the Necessary Corrections	Realign the channel or the levee.
1000	Inflow Channel Element is not a Channel Element in CHAN.DAT	Move inflow node to a left bank or reset the node to floodplain or turn the channel switch on.
1000	Channel Outflow Node Must Have a Lower Bed Elevation Than the Contiguous Upstream Channel Element to Compute a Normal Depth Outflow Condition	Review the channel invert elevation and make the necessary correction so that the outflow node can calculate normal depth. The outflow invert elevation must be lower than that of the upstream node.
1000	Channel Outflow Variable - Kout - in the OUTFLOW.DAT File must be a Channel Element in the CHAN.DAT File	Move the outflow node to a left bank, reset the node to floodplain or turn the channel switch on.
2000	This Grid Cell Has a Hs Inlet and a Full ARF	Move the hydraulic structure node.
2000	This Grid Cell Has a Hs Outlet and a Full ARF	Move the hydraulic structure node.
2000	This Grid Cell Has a Hs Inlet and a Partial ARF	Move the hydraulic structure node or reset the ARF to zero.
2000	This Grid Cell Has a Hs Outlet and a Partial ARF	Move the hydraulic structure node or reset the ARF to zero.
2000	This Grid Cell Has a Hs on a Channel Rb Element	Move the hydraulic structure to the left bank or change it to a floodplain structure.
2000	Inlet on a Full ARF Element	Move Inlet
2000	Hydraulic Structure Has an Adverse Bed Slope. Outlet Invert is Higher Than the Inlet Invert. Please Check to Ensure this is Correct	Review invert elevations. Apply elevation corrections if necessary. Validate structure direction.
2000	Hydraulic Structure Has a Reference Elevation that is Lower Than the Inlet Node Bed Elevation	Correct invert elevation or correct head reference elevation or set head reference elevation to zero.
2000	Hydraulic Structure Has an Inflow or Outflow Element that is Not a Channel	Move inlet node to the channel bank or change it to a floodplain structure.
2000	Hydraulic Structure Has a Name Length Longer Than 30 Characters.	Shorten the Name to Less Than 30 Characters
2000	A Hydraulic Structure Has Been Assigned to a Channel Element. Channel is turned off.	(Ifporchan > 0 line S in HYSTRUC.DAT) and there is no channel component (Ichannel = 0 in CONT.DAT). Turn on channel switch.
2000	Hydraulic Structure Rating Curve, Rating Table, Or Generalized Culvert Switch (Icurvtable) Does Not Match the Assigned Data	Review HYSTRUC.DAT and set the switch to the correct position to match the as- signed data.
2000	Hydraulic Structure must have a Culvert Area Coefficient and Exponent For Routing in a Long Culvert.	The clength and cdiameter was assigned, assign the culvert area coefficient and exponent so FLO-2D can simulate the culvert volume and travel time.
2000	Make Sure that the “Atable” Variable on Line 4 of the HYSTRUC.DAT File is Included	This table is required if clength and cdiameter are used in a Rating Table structure.
2000	First Data Pair of a Hydraulic Structure Rating Table Should Be 0.0. to Interpolate the Next Data Pair	Reset first row of table data to 0.00 0.00.
2000	Hydraulic Structure Rating Curve Stage Must Increase With Increasing Discharge	The rating curve data has an error. Check the data so the discharge increases with increasing stage.
2000	Rate of Change in the Following Hydraulic Structure Rating Tables May Be Unreasonable - Rate of Change = 10 Times Previous Stage Rate of Change	Check the rating table. It may require more data pairs or it may be incorrect.
2000	If the Generalized Culvert Equations are Being Used. The Inoutcont Tailwater Control is Not Necessary. Set Inoutcont = 0	Set inoutcont to 0.
2000	Culvert Length Must Assign in the S-Line of the HYSTRUC.DAT If the Generalized Culvert Equations are Being Used	Assign culvert length and depth in the S line.
2000	Hydraulic Structure Inflow Node is Repeated More Than Once	Review HYSTRUC.DAT. Make sure each inflow node is only listed once. If two nodes are near each other, separate them by a grid element.
2000	Hydraulic Structure Outflow Node is Repeated More Than Once Without Assigning a D-Line Conveyance Capacity Limitation.	Review HYSTRUC.DAT. Make sure each outflow node is only listed once. If two nodes are near each other, separate them by a grid element.
2000	Hydraulic Structure Has a Reference Elevation that is Lower Than the Inflow Node Bed Elevation	Correct invert elevation or correct head reference elevation or set head reference elevation to zero.
2000	Hydraulic Structure Channel Outflow must be a Channel Element	Check the position of the outlet element or make sure the channel switch is on in CONT.DAT.
2000	Hydraulic Structure Has a Reference Elevation that is Lower Than the Inflow Node Bed Elevation	Correct invert elevation or correct head reference elevation or set head reference elevation to zero.
2000	Hydraulic Structure Channel Inflow Element must be a Channel Element	Check the position of the outlet element or make sure the channel switch is on in CONT.DAT.
2000	Hydraulic Structure Inflow Element Cannot Be a Grid System Outflow Element	Correct invert elevation or correct head reference elevation or set head reference elevation to zero.
2000	Hydraulic Structure Outflow Element Cannot Be a Grid System Outflow Element	Move the outlet element to a node that is adjacent to the outflow node.
3000	The Following Cell Has a Full ARF on a Channel Left or Right Bank Element	Realign the channel or eliminate the ARF.
3000	The Following Cell Has a Partial ARF on a Channel Left or Right Bank Element	Delete the ARF.
3000	Street on an Outfall Element	I don’t know how to fix this.
3000	Full ARF on a 1D Street	Realign street or delete ARF.
3000	Partial ARF on a 1D Street	Delete ARF.
3000	Hs Inlet on a 1D Street	Move hydraulic structure or realign street.
3000	Hs Outlet on a 1D Street	Move hydraulic structure or realign street.
3000	Multiple Channel on a 1D Street	Reposition multiple channel nodes or realign street.
3000	Gutter on a 1D Street	Delete gutter or delete street.
3000	Variable Strman is Less Than 0 or Greater Than 1	Assign street Manning’s N correctly.
3000	Variable Istrflo is a Switch, Use Only 0 or 1	Apply variable correctly.
3000	Variable Depx must be Greater Than 0	Assign street depth.
3000	Variable Widst must be Greater Than 0	Assign street width.
3000	Variable Igridn must be Greater Than 0	Assign correct Manning’s n value.
3000	Grid Elements are Defined More Than Once (Street.Dat) For a Street Intersection Within a Grid Element	Delete one of the misassigned street elements.
3000	Street Elements (Street.Dat) are Missing Line “W” in the Street.Dat File	W lines are necessary to define the street direction in the cell. Assign them as shown in Lesson 11.
3000	Variable Istdir must be Greater Than 0 and Less Than or Equal to 8	Add correct street direction.
3000	Variable Widr must be Greater Than 0	Correct street width.
3000	Grid Element ARF Values Were Adjusted	See ARF.DAT for automatic correction list. ARFs were reassigned 1.0 to Eliminate the Potential For Instability Related to Small Surface Area. These are Reported to the ARF_Adjustment.Chk File
3000	Impervious Area Represented By the Rtimp Percentage is Less Than the ARF Value For at Least One Grid Element	Impervious area should represent the building blockage and any other potential impervious area. It should be at least the same as the ARF value.
3000	A Channel Element Has One or More Street Segments. Remove the Street Segments from this Element	Realign the street or channel. Review aerial images to assign channel or street alignment.
4000	Inlet on a Full ARF Element	Move Inlet.
4000	Inlet on a Partial ARF Element	Move Inlet.
4000	Outfall on a Full ARF Element	Move Outfall or delete ARF.
4000	Outfall on a Partial ARF Element	Move Outfall or delete ARF.
4000	Outfall on a Levee Element	Review outfall position. Make sure it is on the correct side of the levee. Review elevation.
4000	Inlet on a Levee Element	Make sure the inlet is on the correct side of the levee. Check the elevation of the cell so that it matches the rim elevation of the inlet or the invert elevation of the type 4.
4000	Duplicate Inlet on SWMMFLO.DAT	Delete the repeated inlet.
4000	Inlet on an Outfall	Reposition the inlet or the outfall.
4000	Outfall on an Outfall	Reposition one of the outfall nodes.
4000	Channel Rb on a Inlet Element	Move the inlet to the left bank.
4000	Channel Rb on an Outfall Element	Move the outfall to the left bank.
4000	Multiple Channel on a Inlet Element	Reposition the inlet or the multiple channel.
4000	Multiple Channel on an Outfall Element	Reposition the outfall or the multiple channel.
4000	There is a Levee and a Storm Drain Inlet Assigned to Grid Cell	Make sure the inlet is on the correct side of the levee. Check the elevation of the cell so that it matches the rim elevation of the inlet or the invert elevation of the type 4.
4000	There is a Storm Drain Inlet Assigned to Completely Blocked Grid Cell	Move the inlet or delete the ARF.
4000	There is a Storm Drain Outfall Assigned to Completely Blocked Grid Cell	Move the outfall or delete the ARF.
4000	There is a Hydraulic Structure and a Storm Drain Inlet Assigned to Grid Cell	Reposition the hydraulic structure or the inlet.
4000	Storm Drain Inlet Has Invert Elevation Errors. Please Check Invert Elevation and Rim Elevation For Node	Do you mean Max Depth?
4000	Curb Opening Height must be Greater Than Zero. Please Revise SWMMFLO.DAT File	Review SWMMFLOW.DAT.
4000	Length must be Greater Than Zero	Review SWMMFLOW.DAT.
4000	Height must be Greater Than Zero	Review SWMMFLOW.DAT.
4000	Typical Weir Drain Coefficient: Range 2.8 to 3.2	Review SWMMFLOW.DAT.
4000	Width or Height must be Greater Than Zero	Review SWMMFLOW.DAT.
4000	Typical Weir Drain Coefficient: 2.3	Review SWMMFLOW.DAT.
4000	Perimeter must be Greater Than Zero	Review SWMMFLOW.DAT.
4000	Area must be Greater Than Zero	Review SWMMFLOW.DAT.
4000	Surcharge Depth must be Greater Than Zero	Review SWMMFLOW.DAT.
4000	There is a Conflict Between Inlets in the SWMMFLO.DAT File and Sub-catchments in the SWMM.INP, Features in Both Lists Need to Be in the Same Order	Check the order of the inlets and the subcatchments.
4000	Inlets in the SWMMFLO.DAT File must be Identical to the Listed Inlets Junction Table of SWMM.INP File	Check the order of the inlets in SWMMFLOW.DAT and SWMM.INP.
4000	Multiple Inlets Assigned to One Grid Cell	Reposition the inlet or delete it if it is a repeated line.
4000	There is a Type 4 Inlet (Review SWMMFLO.DAT File) that is Missing the Rating Table in the SWMMFLORT.DAT File	Add the table to SWMMFLOWRT.DAT.
4000	There is an Inflow Node and a Storm Drain Inlet Assigned to Grid Cell	Reposition the inflow node or the inlet.
4000	There is an Inflow Node and a Storm Drain Outfall Assigned to Grid Cell	Reposition the inflow node or the outfall.
4000	There is an Outflow Node and a Storm Drain Inlet Assigned to Grid Cell	Reposition the inlet.
4000	There is an Outflow Node and a Storm Drain Outfall Assigned to Grid Cell	Reposition the outfall or delete the outlet.
4000	Storm Drain Outfall Nodes are in Channel Interior Elements, Re-Assign to the Channel Elements in CHAN.DAT	Reposition the nodes to the left bank or reassign then grid element in SWMMFLO.DAT.
5000	Cross-Section Element Can Only Be Assigned Once in the FPXSEC.DAT File.	Remove repeated grid elements in FPXSEC.DAT. If the Cross-Section Includes the Channel Use Only the Left Bank Channel Element in CHAN.DAT
6000	Variable Xconc Should Not Be Assigned If Mudflow With a Sediment Concentration is Assigned to the Inflow Hydrograph	Do not assign Xconc in CONT.DAT.
6000	No Sediment Data in the SED.DAT File	Check the SED.DAT file.
6000	Error in Line 1 (M-Line) of the SED.DAT File	Check the SED.DAT file for missing or incorrect mudflow data.
6000	Dry Weight of Sediment is Zero in the SED.DAT File and Thus the Porosity is Also Zero	Set the Dry Weight variable in SED.DAT.
6000	Sediment Size Exceeds the Recommended Value For the Application of the Yang Equation	Check the sediment size fractions in SED.DAT.
6000	Error in Line 2 (S-Line) of the SED.DAT File	Check the sediment transport data in SED.DAT.
6000	Error in Z-Line of the SED.DAT File	Check the sediment transport equation, bed thickness or volumetric concentration.
6000	Error in P-Line of the SED.DAT File	Check the sediment diameter and percentage.
6000	Error in D-Line of the SED.DAT File	Check the debris basin volume and the debris grid element number.
6000	Scourdep Variable in SED.DAT Line E Should Be Positive (>0.)	Check the scour depth.
6000	Error in E-Line of the SED.DAT File	Check the grid element numbers or position in the rigid bed cells.
6000	Error in R-Line of the SED.DAT File	Check the sediment supply coefficient and exponent.
6000	Error in S-Line of the SED.DAT File	Check the size distribution for sediment supply.
6000	Error in N-Line of the SED.DAT File
6000	Isedn variable is incorrect.	Isedn Variable Must Equal One of the Sediment Size Fraction Groups in SED.DAT that is Associated With a Sediment Transport Equation. Do Not Assign Isedn to a Sediment Transport Equation Number
7000	There are a Levee Element on a Complete Blocked Element	Isedn Variable Must Equal One of the Sediment Size Fraction Groups in SED.DAT that is Associated With a Sediment Transport Equation. Consider repositioning or deleting the levee.
7000	There are a Levee Element on a Partial Blocked Element	Isedn Variable Must Equal One of the Sediment Size Fraction Groups in SED.DAT that is Associated With a Sediment Transport Equation. Make sure the levee is on the correct side of the cell.
7000	There are a Levee Element With a WRF	Isedn Variable Must Equal One of the Sediment Size Fraction Groups in SED.DAT that is Associated With a Sediment Transport Equation. Make sure the levee and WRF relationship is correct.
7000	This Grid Cell Has a Hs Inlet on a Levee Element	Make sure the hydraulic structure is on the correct side of the levee. Review the grid element elevation so that the water can get to and from the structure inlet and outlet nodes.
7000	This Grid Cell Has a Hs Outlet on a Levee Element	Make sure the hydraulic structure is on the correct side of the levee. Review the grid element elevation so that the water can get to and from the structure inlet and outlet nodes.
7000	This Grid Cell Has Two Levees	Delete the repeated levee.
8000	This Grid Cell Has an Inflow on a Multiple Ch Element	Move the inflow node.
8000	This Grid Cell Has an Inflow on a Multiple Ch Element	Move the inflow node.
8000	This Grid Cell Has an Inflow on a Multiple Ch Element	Move the inflow node.
8000	This Grid Cell Has a Full/Partial ARF or WRF on a Multiple Ch Element	Remove the ARF/WRF.
8000	This Grid Cell Has a Full/Partial ARF or WRF on a Multiple Ch Element	Remove the ARF/WRF.
8000	This Grid Cell Has a Full/Partial ARF or WRF on a Multiple Ch Element	Remove the ARF/WRF.
8000	Channel Lb Rb on a Multiple Channel Element	A multiple channel cannot be assigned to a bank element. See reference manual.
8000	Channel Lb Rb on a Multiple Channel Element	A multiple channel cannot be assigned to a bank element. See reference manual.
8000	Levee on a Multiple Channel Element	Make sure the multiple channel is on the correct side of the levee.
8000	Multiple Channel Element on a Multiple Channel Element	Delete one of the repeated lines in MULT.DAT.
8000	Levee on a Multiple Channel Element	Make sure the multiple channel is on the correct side of the levee.
8000	Multiple Channel Element on a Multiple Channel Element	A multiple channel cannot be assigned to a bank element. See reference manual.