HydroCAD Messages

This document lists all HydroCAD messages in numerical order.  Messages are grouped into three categories based on severity:

Messages # 1-31 are calculation Notes.  They provide basic information about the calculations being performed

Message # 37-62 are calculation Hints.  They indicate items that may require further attention.

Message # 63-99 are calculation Warnings.  They indicate a serious condition that must be investigated and addressed.

Message # 100-900 indicate that a certain operation has failed and could not be completed.

Calculation Notes:

[01] Note: {node}
 Duplicate node number skipped

A node was encountered with a number that was already in use. The node is skipped, and the program continues to process any additional nodes.

This message usually occurs while adding a project that contains nodes that don't have unique numbers.  Before adding a project, you should generally renumber any nodes with conflicting numbers.  To add any nodes that were skipped, renumber the applicable nodes and add the project again.

The message can also occur when pasting nodes from the clipboard, or opening a project that contains duplicate node numbers.

Tip: To make a clone of an existing node use Ctrl-drag (rather than cut and paste.)

[02] Note:
 Exceeded node capacity

The current project has exceeded the nominal node capacity of your program.

You can continue to work with the project, but you will not be able to save the project or produce multi-page reports unless you reduce the number of nodes.  The automatic project backup will also be suspended until the number of nodes is reduced.

Warning: If you're using the HydroCAD Sampler, your changes will be lost when the Sampler's time limit expires.  To save your project you must reduce the number of nodes before the time limit expires.

[03] Note:
Added x nodes and updated y nodes

This message indicates the number of nodes that have been added and/or updated by the Project|Add or Project|Merge command.

[04] Note:
Repositioned x nodes

This message indicates that a number of nodes have been repositioned for better visibility. This occurs automatically if the nodes don't contain the expected position information.   The repositioned nodes are selected and aligned in a row at the bottom of the routing diagram.

This situation occurs primarily with project files that are generated by another application with doesn't provide position information. To avoid automatic repositioning of nodes, be sure they have a valid position before the file is opened in HydroCAD.

[10] Note:
 Updating to {node} as needed

Routing calculations are being performed up to a specific node.  To save time, downstream nodes are not being calculated, unless a dynamic or simultaneous routing method is selected.  Any other nodes will be automatically updated when required.

[13] Note:
 Time span = 5-20 hrs,  dt= .05 hrs,  301 Points

This message indicates the time span and time increment (dt) being used to generate and route hydrographs.  The message also indicates the number of points in the resulting hydrographs.

[16] Note:
 Runoff by SCS TR-20 method, UH=SCS

This message indicates the method being used to produce runoff hydrographs.

When using the SCS method, the message also indicates the Unit Hydrograph (UH) being employed.

When using the Rational method, the message indicates the hydrograph rise/fall rates.

These parameters may be changed with Settings|Calculation.

[18] Note:
 Sample County 10-Year Duration=20 min, Inten=4.30 in/hr, Cf=x.x 

This message indicates the current IDF file and rainfall event, plus the duration, intensity, and frequency factor being used with the Rational method.

These parameters may be changed with Settings|Calculation, or by selecting another rainfall event.

[19] Note:
 Type II 24-hr 10-Year Rainfall= 4.30" x2, AMC=3, Ia/S=0.05

This message indicates the rainfall distribution, rainfall event name, and rainfall depth being used to generate runoff hydrographs.

The letter "x" indicates that several back-to-back storms are being generated, with the specified rainfall depth occurring in each of the storms.

The Antecedent Moisture Condition (AMC) is shown for dry, wet, or saturated conditions (1, 3 or 4).  For normal conditions (AMC 2) the value is not shown.

The ratio of Ia to S is shown whenever the default value of 0.2 has been changed.

These parameters may be changed with Settings|Calculation.

[22] Note:
 Reach routing by Stor-Ind+Trans method

This message indicates the method being used to perform hydrograph routing through each reach.

The routing method may be changed using Settings|Calculation.

[25] Note:
 Pond routing by Stor-Ind method

This message indicates the method being used to perform hydrograph routing through each pond.

The routing method may be changed using Settings|Calculation.

[28] Note:
 Updating {node}

This message indicates that runoff or routing calculations are being updated for a given node.

Routing calculations are automatically updated as required to view or print reports.  HydroCAD employs a "minimal recalculation" feature, so that only the required nodes are updated at any given time.

Upstream nodes are automatically updated as required to produce a valid inflow. During a dynamic or simultaneous routing, any downstream nodes that contribute to a tailwater effect are updated concurrently. Otherwise, downstream nodes are just marked as "invalid" and will be updated as their results are required.

Additional information is available on the calculation process employed for each subcatchment, reach, pond, and link.

[31] Note:
 Calculations complete

This message indicates that all the calculations required at this time have been completed.

Some nodes may not have been updated, if their results were not immediately required.

Calculation Hints:

[37] Hint:
 Longer time span advised for full volumes

The calculation time span may not be long enough to encompass the entire hydrograph duration.  This may cause the reported hydrograph volume, runoff depth, and detention time to be less that the "true" values.  Peak flows generally are not affected by this situation.

  • If you wish to study the entire hydrograph volume, you may set a longer time span on the Settings|Calculation screen.

    Before increasing the time span, a visual inspection of the hydrograph is recommended.  If the hydrograph is visibly truncated at the beginning or end, a longer time span is suggested.  On the other hand, this message may be triggered by a relatively minor condition that does not merit a longer time span.

    Certain conditions, such as a base flow or a pond with an extended discharge, can also trigger this message.  In these cases you may not need to set a longer time span.  However, due to the extended duration of flow, the reported volumes will be dependent on the time span you select.
     

    [40] Hint:
     {node} Not described

    No description has been entered for the node, or the data is incomplete.  For a subcatchment, no runoff is produced.  For a reach, pond, or link, any inflow is passed through unchanged.

    To describe the node, select Node|Edit.

    An undescribed node can be useful during initial design work, since it allows a node to be placed on the diagram but not described until later.

    [43] Hint:
     {node} Has no inflow (Outflow=Zero)

    This node has no inflow on the routing diagram, so it will produce no outflow unless it has a base flow and/or initial water surface elevation.

    [45] Hint:
     Subcat Runoff=Zero

    The subcatchment has produced no runoff.  This can occur in any of the following situations:

    1) The entire runoff may be occurring before or after the specified time span.  To change the time span use Settings|Calculation.

    2) For the SCS or SBUH methods, the rainfall depth may be insufficient to generate any runoff as determined by the SCS runoff equation.  This is normal when low rainfall depths are used in combination with low curve numbers.

    [46] Hint:
     Subcat Tc=0 (Instant runoff peak depends on dt)

    When the time-of-concentration is zero, the precipitation excess appears immediately as runoff.  Since the calculated peak flow is based on the average over each time interval (dt), using a longer dt (in relation to the peak duration) will yield a lower "peak" flow.

    If the instantaneous peak is required, reduce the dt.  The dt may be changed using Settings|Calculation: Time Span.

    Note: The calculated runoff volume is not affected by the dt setting.

    [48] Hint:
     Subcat Peak<CiA due to short duration

    Due to the short rainfall duration, the peak runoff has not had time to attain the full value predicted by the Rational Method equation Q=CiA.

    In order to attain the full peak, the rainfall duration must be greater than or equal to the Time-of-Concentration multiplied by the Rise Rate.  Shorter durations will produce a proportionately lower peak.

    Short durations may also reduce the total runoff volume.  For further details, see the Rise/Fall tab of the Calculation Settings screen.

    [49] Hint:
     Subcat Tc<2dt may require smaller dt

    When the time-of-concentration is less than twice the time increment (dt), the instantaneous peak may exceed the (average) hydrograph peak for a brief time (less than dt).

    If the instantaneous peak is required, reduce the dt.  A dt of one-half the smallest Tc will prevent this message from occurring.  The dt may be changed using Settings|Calculation: Time Span.

    Note:  The runoff volume is not affected by the dt setting.
     

    [51] Hint:
     xx Area used default ground cover / soil group

    When importing watershed data, a ground cover or soil group was not specified for all areas, so the default value was used for those areas. The message will also indicate the default that was used, plus the area to which it was applied.

    The default ground cover and soil group are specified on the Settings|Watershed screen. When using a default value, be sure to draw all areas that should not use the default.

    [52] Hint:
     Reach Inlet/Outlet conditions not evaluated

    Reach routing calculations assume normal-flow conditions in the channel or pipe.  The software does not evaluate reach inlet conditions or tailwater, although these may often be a controlling factor.

    If you wish to consider entrance losses, pressure flow, or other conditions for a pipe, it should be modeled as a pond with a culvert outlet.  You can automatically convert a pipe reach to a pond with Node|Convert to Pond.

    [55] Hint:
     Reach Peak inflow is 1xx% of Manning's capacity

    The reach is operating above its Manning's normal-flow capacity, but has not overtopped.  This may be acceptable depending on the design criteria.

    [56] Hint:
     Dam breach started at x.xx hrs WSE=xxx.x'

    A dam breach has commenced at the indicated time and water surface elevation.  For details read about dam breach calculations.

    [57] Hint:
     Pond Peaked at xxx' (Flood elevation advised)

    The peak water surface elevation is displayed. Since a flood elevation has not been specified, HydroCAD is unable to determine if this is an acceptable elevation.

    If the peak elevation is higher than expected, make sure you have defined all necessary outlet devices.  For example, if the level exceeds the top of your pond or catch basin, you must define a suitable overflow device.  Otherwise, the elevation may attain an unrealistic level.

    It is also recommended that you define a flood elevation for this node.  This will allow a warning message to be automatically generated whenever the water surface exceeds the specified elevation.  Setting a flood elevation will also improve calculation speed by allowing a better estimate of the elevation range prior to routing.

    [58] Hint:
     {node} Peaked x.x' above defined flood level

    The peak depth in a reach or pond has exceeded the defined flood elevation. Routing continues as usual.  (A separate warning message occurs whenever a reach or pond exceeds the highest defined stage.)

    The significance of this message depends on the flood level that has been specified for this node.  The message does not indicate that the calculations themselves have been compromised.

    If the peak elevation is higher than expected, make sure you have defined all necessary outlet devices.  For example, if the level exceeds the top of your pond or catch basin, you must define a suitable overflow device.  Otherwise, the elevation may attain an unrealistic level.

    [59] Hint:
     Culvert outlet resized to  xx"

    The specified culvert outlet or pipe reach has been resized according to the criteria established on the Resize tab of the Settings|Calculation form.

    Up to HydroCAD 8.0:

    HydroCAD 8.5 and later:
    [61] Hint: {node} Submerged xx% of Reach x bottom

     The node's peak elevation has partially submerged the bottom of an inflowing reach.

    This message occurs when the peak elevation (tailwater) is greater then the outlet invert but less than the inlet invert.  The percentage indicates the fraction of the reach length that is submerged.  If the tailwater had risen above the inlet invert a separate warning message would have been issued.

    Important:  The reach routing calculations are not altered by this situation.  The routing continues to be performed as if the reach were operating under normal Manning's flow with no tailwater influence.  The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation.  In some situations, an alternate routing method or modeling technique may be required.

    Reminder: In most situations, a pipe reach is best modeled as a pond with a culvert outlet.     		[61] Hint: {node} Exceeded Reach x outlet invert by x.x' @ x.x hrs

    The node's peak elevation has exceeded the outlet invert of an inflowing reach, but did not exceed the reach's outlet depth at any time during the routing.

    This degree of tailwater is common, and does not necessarily require further action. The reach routing calculations continue to be performed as if the reach were operating under normal Manning's flow with no tailwater influence. The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation. In some situations, an alternate routing method or modeling technique may be required.

    If the tailwater had risen above the outlet depth, a more serious warning message would have been issued.
    [62] Hint: {node} Submerged xx% of Reach x inlet

    The node's peak elevation has partially submerged the inlet of an inflowing reach.

    This message occurs when the peak elevation (tailwater) rises above the inlet invert but remains below the calculated inlet depth at all times.  The percentage indicates the fraction of the defined reach depth that is submerged at the inlet.

    Important:  The reach routing calculations are not altered by this situation, even though it may reduce the actual reach discharge.  The routing continues to be performed as if the reach were operating under normal Manning's flow with no tailwater influence.  Since these basic routing assumptions are no longer valid, an alternate routing method or modeling technique may be required.  The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation.

    Reminder: In most situations, a pipe reach is best modeled as a pond with a culvert outlet, which can accommodate a wider range of tailwater conditions.    		 [62] Hint: {node} Exceeded Reach x OUTLET depth by x.x' @ x. hrs

    At some time during the routing, the node's water surface elevation has exceeded the flow depth at the reach outlet, but always remained below the inlet depth. The message indicates the maximum amount of exceedance, and the time at which it occurred.

    This message indicates that part of the reach has been "flooded out" by the downstream node.

    Important: The reach routing calculations are not automatically changed to accommodate this situation, even though it may reduce the actual reach discharge. The routing continues to be performed as if the reach were operating under normal Manning's flow with no tailwater influence. Since these basic routing assumptions may no longer be valid, an alternate routing method or modeling technique may be required. The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation.

    If the tailwater had risen above the inlet depth, a more serious warning message would have been issued.

    Calculation Warnings:

    Red warning messages indicate that calculations have exceeded acceptable conditions. Runoff and routing results may not be reliable while any warning messages are present!  Even with a "failed" system you need to resolve the warnings in order to accurately simulate the failure.

    Any "Storage Exceeded" or "Oscillation" warnings should be addressed first, since they may indicate problems that effect the entire model, and can cause secondary warnings to occur.

    Click on any item in the HydroCAD Message Window for a detailed explanation.

    [63] Warning:
     {node} Exceeded Reach x INLET depth by x.x' @ x.x hrs

    At some time during the routing, the node's water surface elevation has exceeded the flow depth at the reach inlet, indicating a tailwater dependency, or even the potential for reverse flow. The message shows the maximum amount of reverse head and the time at which it occurred

    Important: The reach routing calculations are not automatically changed to accommodate this situation, even though the higher tailwater may in reality cause a reduction in flow, or even a reverse flow. The routing continues to be performed without tailwater effects or reverse flow, as if a one-way valve were preventing any backflow. The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation.

    Note: If the reach is being used to connect two ponds, you may want to remove the reach and connect one pond directly to the next. This will provide additional capabilities for handling the tailwater effects.

    [65] Warning:
     Reach Inlet elevation not specified

    The reach inlet elevation has not been specified.  This information is required in order to detect potential tailwater effects.

    Note: An undefined invert elevation commonly occurs with projects that were imported from HydroCAD 5 or earlier.  These projects considered only the reach depth, and had no knowledge of the reach elevation in relation to other nodes.

    Use Node|Edit:Profile to specify the inlet elevation for each reach.

    [67] Warning:
     {node} Inflow not allowed - Ignored

    This node cannot accept an inflow hydrograph.  The inflow is ignored.

    Separate procedures are available if you need to route a hydrograph through a subcatchment.

    [68] Warning:
     Import data skipped

    Some of the imported data could not be fully processed.  The data that was skipped is listed before this message, and in the     project notes.

    This warning may occur when importing data from TR-20.  In order to properly replicate the results obtained with the original data, the skipped items must be manually incorporated into the HydroCAD project.

    After incorporating the skipped items, you should open the Project|Notes screen and update that information accordingly.

    [70] Warning:
     Subcat Tc<8dt requires smaller dt

    The rising limb of a Rational Method hydrograph contains fewer than eight ordinates.  A smaller dt is recommended in order to accurately represent the hydrograph.  (A dt of .01 hours is generally appropriate for most Rational method calculations.)  Inspection of the hydrograph is also advised.

    The dt may be changed using Settings|Calculation: Time Span.

    [73] Warning:
     Subcat Peak may fall outside time span

    The calculated runoff peak isn't within the middle 90% of the specified time span.  Under these conditions, the reported "peak" is the highest flow within the time span, and may not be the true peak.

    Inspect the hydrograph and change the time span to include the peak.  The time span may be changed using Settings|Calculation: Time Span.

    [74] Warning:
     xx Area has no ground cover/soil grouptime

    When importing watershed data, a ground cover or soil group was not specified for certain areas.  The message will indicate the amount of area that had no ground cover or soil group.

    Because a ground cover or soil group was not specified, the Curve Number cannot be determined for these areas.  To resolve the problem, revise the input data or specify default values on the     Settings|Watershed screen.

    [76] Warning:
     Reach Detained x.xx AF (Pond w/culvert advised)

    A pipe reach has filled with water, causing the flow to be limited and the excess volume to be detained without head.

    IMPORTANT: Pipe reach calculations assume normal-flow conditions in the pipe.  If you wish to consider entrance losses, pressure flow, or other conditions, the pipe should be modeled as a pond with a culvert outlet. 

    [77] Warning:
     Pond Manual tailwater submerged device # by x.x'

    The pond's manual tailwater elevation exceeds an outlet device which is not tailwater-aware.  This message occurs when the manual tailwater setting is above the invert of one of the pond's final outlet device(s), and that device is not able to respond to tailwater conditions.

    Important:  The pond routing calculations are not altered by this situation, even though the manual tailwater may reduce the pond's actual discharge.  The routing continues to be performed based on the existing stage-discharge relationship, as if the tailwater did not exist.

    This message can occur only for specific types of outlet devices that are unable to respond to tailwater conditions, such as exfiltration and some special outlets.  To resolve the situation, either adjust the existing device to accommodate the tailwater, or switch to another device that has the ability to respond to tailwater, such as a weir or orifice.

    [78] Warning:
     {node} Submerged Pond x device # by x.x'

    The node's peak elevation has submerged the specified pond outlet device.  This message occurs when the peak elevation (tailwater) rises above the invert of one of the pond's final outlet device(s), and that device is not able to respond to tailwater conditions.

    Important:  The pond routing calculations are not altered by this situation, even though the tailwater may reduce the pond's actual discharge.  The routing continues to be performed based on the existing stage-discharge relationship, as if the tailwater did not exist.

    This message can occur only for specific types of outlet devices that are unable to respond to tailwater conditions, such as exfiltration and some special outlets.  To resolve the situation, either adjust the existing device to accommodate the tailwater, or switch to another device that has the ability to respond to tailwater, such as a weir or orifice.

    Note: This message does not indicate a potential reverse-flow condition.  A separate message is generated whenever a reverse-flow potential exists.

    [79] Warning:
     {node} Submerged Pond x device # by x.x'
    The node's peak elevation has submerged the specified pond outlet device.  This message occurs when the peak elevation (tailwater) rises above the invert of one of the pond's final outlet device(s).

    Important:  The pond routing calculations are not altered by this situation, even though the tailwater may reduce the pond's actual discharge.  The routing continues to be performed based on the existing stage-discharge relationship, as if the tailwater did not exist.

    Since a static stage-discharge curve cannot accommodate a variable tailwater, the tailwater must be specified manually using Node|Edit:Tailwater.  If one of these tailwater options isn't sufficient, an alternate routing method may be required.  The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation.

    Note: This message does not indicate a potential reverse-flow condition.  A separate message is generated whenever a reverse-flow potential exists.

    [80] Warning:
     {node} Exceeded Pond x by x.x' @ x.x hrs (x.x cfs x.x af)

    At some point during the routing, the node's elevation has exceeded the elevation of an inflowing pond, indicating a possible reverse flow.  The message shows the maximum amount of reverse head, the time at which it occurred, and an estimate of the potential reverse flow.

    In some situations, the reverse head may be caused by an excessively large time increment.  Reduce the dt or increase the finer routing increment to see if this reduces or eliminates the problem.  Certain routing methods may require a finer routing increment when two adjacent nodes have very similar water surface elevations.

    Important:  The pond routing is not altered by this situation, even though the higher tailwater may in reality cause a reverse flow.  The routing continues to be performed as if a one-way valve were preventing the backflow.  The user is responsible for adjusting the model in any way that is deemed necessary to accommodate this situation.  If the potential reverse flow volume is significant in proportion to the total outflow volume, you can consider modeling a reverse flow, which will also suppress this warning.

    Note: This and other warning messages can be triggered by basic routing failures, such as oscillations.  If any oscillation warnings are present, these must be resolved first.

    [81] Warning:
     {node} Exceeded Pond x by x.x' @ x.x hrs

    At some point during the routing, the node's elevation has exceeded the elevation of an inflowing pond, indicating a possible tailwater dependency.  The message shows the maximum amount of reverse head and the time at which it occurred.

    Important:  The pond routing is not altered by this situation, even though the higher tailwater may in reality cause a reduced discharge.  To remedy the situation, select a pond routing method that is able to handle tailwater effects.

    Note: This and other warning messages can be triggered by basic routing failures, such as oscillations.  If any oscillation warnings are present, these must be resolved first.

    [82] Warning:
     Early inflow requires earlier time span

    Some inflow may be occurring before the beginning of the specified time span, and is therefore not included in the routing.  An earlier time span is required in order to include the early part of the inflow hydrograph.

    The time span may be changed using Settings|Calculation: Time Span.

    [85] Warning:
     {node} Oscillations may require Finer Routing>1

    The outflow of a pond or reach contains a greater number of peaks than the inflow, suggesting that oscillations may have been induced by the routing.

    Examine the hydrograph plot.  In some cases this message may be triggered by normal routing conditions.  If a visual inspection does reveal oscillations, they can usually be eliminated by setting the finer routing value to 2 or 3 for that particular node.  (See the Advanced tab of the applicable node.)  If this fails to correct the problem, the available storage may be too small to permit an accurate routing for this node.

    Note: Reducing the overall time increment (dt) may also resolve the problem, but this will increase the calculation time for other nodes.

    Important:  Since oscillations can trigger additional warnings in this or other nodes, any oscillation warnings should always be addressed first.  It is common for oscillations to trigger secondary warnings in other nodes, and these will usually cease when the oscillation condition is corrected. 

    [86] Warning:
     {node} Oscillations may require smaller dt

    The outflow of a pond or reach contains a greater number of peaks than the inflow.  This suggests that oscillations were induced by the routing and that the routing results may not be valid!

    Examine the hydrograph plot.  In some cases, this message may be triggered by normal routing conditions.  If a visual inspection reveals oscillations, reduce the time increment (dt) until the situation is corrected.  This may require a reduction to the minimum dt of 0.01 hours.

    If you are using the Sim-Route procedure, the available storage may be too small to permit an accurate routing.  When modeling very small ponds, catch basins, or manholes, the Dyn-Stor-Ind method may produce better results.  Also try the Catch basin option for the applicable ponds.

    Important:  Since oscillations can trigger additional warnings in this or other nodes, any oscillation warnings should always be addressed first.  It is common for oscillations to trigger secondary warnings in other nodes, and these will usually cease when the oscillation condition is corrected. 

    [87] Warning:
     {node} Oscillations may require Finer Routing or smaller dt

    The outflow of a pond or reach contains a greater number of peaks than the inflow, suggesting that oscillations may have been induced by the routing.

    Examine the hydrograph plot.  In some cases, this message may be triggered by normal routing conditions.  If a visual inspection does reveal oscillations, they can usually be eliminated by increasing the finer routing value on the Setting|Calculation screen or by reducing the overall time increment (dt).  If this fails to correct the problem, the available storage may be too small to permit an accurate routing for this node.

    Important:  Since oscillations can trigger additional warnings in this or other nodes, any oscillation warnings should always be addressed first.  It is common for oscillations to trigger secondary warnings in other nodes, and these will usually cease when the oscillation condition is corrected. 

    [88] Warning:
     {node} Qout>Qin may require Finer Routing>1

    The peak outflow of a pond or reach was greater than the peak inflow.  This can occur if the storage is very small in relation to the inflow volume, or if there are abrupt changes in the stage-discharge curve or inflow hydrograph.

    Examine the hydrograph plot.  In some cases, this message may be triggered by normal routing conditions.  If a visual inspection confirms the presence of routing problems, set the finer routing value to 2 for that particular node.  (See the Advanced tab of the applicable node.)  If this fails to correct the problem, the available storage may be too small to permit an accurate routing for this node.

    Note: Reducing the overall time increment (dt) may also resolve the problem, but this will increase the calculation time for other nodes.

    [89] Warning:
     {node} Qout>Qin may require smaller dt

    The peak outflow of a pond or reach was greater than the peak inflow.  This can occur if the storage is very small in relation to the inflow volume, or if there are abrupt changes in the stage-discharge curve or inflow hydrograph.

    Examine the hydrograph plot.  In some cases, this message may be triggered by normal routing conditions.  If a visual inspection confirms the presence of routing problems, reduce the time increment (dt) until the situation is corrected.  This may require a reduction to the minimum dt of 0.01 hours.

    If you are using the Sim-Route procedure, the available storage may be too small to permit an accurate routing.  When modeling very small ponds, catch basins, or manholes, the Dyn-Stor-Ind method may produce better results.  Also, try the Catch basin option for the applicable ponds.

    [90] Warning:
     {node} Qout>Qin may require Finer Routing or smaller dt

    The peak outflow of a pond or reach was greater than the peak inflow.  This can occur if the storage is very small in relation to the inflow volume, or if there are abrupt changes in the stage-discharge curve or inflow hydrograph.

    Examine the hydrograph plot.  In some cases, this message may be triggered by normal routing conditions.  If a visual inspection confirms the presence of routing problems, they can usually be eliminated by increasing the finer routing value on the Setting|Calculation screen or by reducing the overall time increment (dt).  If this fails to correct the problem, the available storage may be too small to permit an accurate routing for this node.

    [91] Warning:
     Reach Storage range exceeded by xx'

    The water surface elevation has exceeded the highest defined stage. Routing continues using a linear extrapolation of the storage and discharge curves, which may produce unreliable results.

    Important:  For accuracy, you must extend the stage-storage data in order to prevent extrapolation.

    [92] Warning:
     Pond Outlet Device x is above defined storage

    The invert of the specified outlet device lies above the defined storage range, and therefore does not contribute to the pre-calculated stage-discharge curve.  This can result in no flow being allowed through the device.

    Important: In order for the device to be properly evaluated, additional storage information must be provided so that the device falls within the defined storage range.  There should be at least one defined stage above the top of the highest outlet device.

    [93] Warning:
     Pond Storage range exceeded by xx'

    The water surface elevation has exceeded the highest defined stage.  All defined storage has been filled.  Routing continues by applying additional head to the outlet(s), but without utilizing any additional storage.  In essence, the pond has been extended upward as a pencil-thin chamber with no additional storage.  (For details, see the pond's stage-storage plot.)  

    Important:  For accuracy, you must define additional storage in order to accurately represent the physical situation being modeled.  This may consist of additional stage-storage data and/or storage chambers, as required to describe the actual storage.  The additional storage may also resolve other warnings (such as oscillations) that can result from inadequate storage.

    This warning commonly results from a failure to provide storage data above the highest outlet device, such as an emergency spillway.  Although you may not intend to utilize this storage, complete storage information is required in order to perform an accurate routing.  When using custom stage-storage data, the situation is easily resolved by entering storage at one or more elevations above the upper-most outlet.

    It is also possible that you have failed to include an overflow device for the pond, causing the elevation to rise beyond the expected level.

    Note: If the storage volume is actually sealed (no additional storage is available) then the warning does not necessarily indicate a problem.  Under these conditions the storage volume will become pressurized.

    [95] Warning:
     Pond Outlet Device #1 rise exceeded

    The water level has exceeded the rise of the specified outlet device (usually a weir), but no matching device was found to handle the flow at higher elevations.  Calculations will continue using orifice flow through the specified rise, but without using any additional flow area.

    Important: To obtain accurate results, you probably need to define another outlet device (generally a weir) to handle the flow that will occur when the headwater exceeds the top of the lower weir.  In order to suppress this message, the invert of the upper weir must be equal to the lower weir's invert plus its rise.

    Note: When using a custom weir to model an orifice, including a final zero-width stage will suppress this warning message.

    For details read about weir rise.

    [97] Warning:
     Reach Factor X Out Of Range

    The X-factor used by the Muskingum-Cunge routing procedure has exceeded the permissible range of 0.0 to 0.5.  The routing has been performed using the corresponding limit.

    Important:  To obtain a valid routing, you must adjust the routing parameters as required to produce a coefficient within the expected range.  For further details see the routing results in the reach summary, as well as the description of the Muskingum-Cunge routing procedure.

    [98] Warning:
     Max. Lift of x.xx' exceeds pump rating
    At some time during the routing, the required lift was greater than the pump could deliver. No pump flow occurs under these conditions. If you intend to operate the pump at this lift, you should insert additional points at the beginning of the rating table to adequately describe the pump flow under high head (low flow) conditions.

    [99] Warning:
     Min. Lift of x.xx' is below pump rating

    At some time during the routing, the pump lift was below the range specified by the rating curve. Under these conditions, the pump flow is assumed to be the highest value specified in the rating table. If you intend to operate the pump at this lift, you should add additional points at the end of the rating table to adequately describe the pump flow under low head (high flow) conditions.


    Other Messages:

    These messages maybe displayed in conjunction with other HydroCAD operations..

    Warning 111: Invalid Serial Number

    The serial number you entered is not valid.  Please check your CD sleeve or download email for the correct serial number.

    These are the only places your complete serial number will appear.  If you lose this information, you will need to order a replacement serial number.

    Warning 112: Duplicate Serial Number Skipped

    A duplicate serial number was found and ignored.  Unless another valid serial number is present, HydroCAD will not run.

    This can occur if you enter a revised serial number without removing the old one.  To correct the problem, remove one of the duplicate numbers on the Settings|Serial Number screen.

    Note that a duplicate serial number is one that contains the same digits up to the decimal point.  This portion of the number is permanently assigned to your program and will not change from one version to the next.

    Warning 114: Outdated Serial Number Skipped

    An outdated serial number, was encountered and ignored.  Unless another valid serial number is present, HydroCAD will not run.

    This can occur after installing a HydroCAD update, if you fail to enter the revised serial number that came with your update.

    To restore the full capabilities of your program, open the Settings|Serial Number screen and enter the new serial number(s) from your CD sleeve or download email.  Also be sure to remove the original (outdated) serial number.

    Warning 115: More Recent Serial Number Skipped

    A serial number from a more recent release was found and ignored.  Unless another valid serial number is present, HydroCAD will not run.

    This can occur if you enter the serial number for a HydroCAD update, but fail to install the update itself.  If you are sharing your license over a network, someone else may have installed a new version without updating your computer.

    To correct the situation, install the correct update on your computer.  If you specifically need to run both versions concurrently, you may be able to do this by entering both the old and new serial numbers on the Settings|Serial Number screen.

    Warning 120: Remove Earlier Serial Number

    When upgrading to a larger node capacity, you must remove the previous (lower capacity) serial number, or HydroCAD will continue to operate with the lower node capacity.  Use the Settings|Serial Number screen to view and remove the old serial number.

    Warning 122: Sample project files not found

    Sample data files were not found for the current user. Re-run the setup program in order to create the missing files for the current user.

    When HydroCAD is installed, sample data files are created only for the current user. Although other users can run the basic software, they will not have a private copy of the sample files unless they install HydroCAD using their own login credentials.

    Installing HydroCAD again will not cause any conflicts or create any duplicate files except for these specific samples.

    Error 130: Unable to Create User File

    HydroCAD was unable to create a user file in the license folder.  This is usually the result of a network drive being off-line or having inadequate access rights.  Each HydroCAD user must have full read, write, and creation rights to this folder.

  • To resolve this situation, re-establish the connection to the specified folder and click the Retry button.
  • If the folder is permanently unavailable, click the Yes button to abandon this folder and revert to the default license folder.  You will then be prompted to re-enter your HydroCAD serial number(s).
  • To defer any action, click the No button to exit from HydroCAD without changing your settings.  You can run HydroCAD later when the folder is available.

    Technical Note:  By default, license information is stored in the HydroCAD program folder, which is usually C:\Program Files\HydroCAD.  However, you may change the license folder in order to share your license(s) over a network.  If you are getting this error message, it usually means that you have changed the license folder, and that the folder is no longer available.  This can happen if the folder has been deleted, or if the computer containing the license folder has been turned off or disconnected from the network.
     

    Error 140: Incomplete Installation

    HydroCAD has been improperly installed, or the installation has been damaged.  To correct the problem, you must run the original HydroCAD setup program.  

    This situation occurs most often when attempting to manually move the program to a different computer or folder.  If you need to move the program, you should first uninstall the original program, and then reinstall HydroCAD in the new location.  (Uninstalling HydroCAD will not alter your settings or project files.)

    If you want to run HydroCAD on more than one computer (subject to the License Agreement), you must repeat the installation process on each computer.  (Manually copying the files from one computer to another will not work.)

    If you still get this error after a successful installation, make sure HydroCAD is not configured to run in Windows "Compatibility Mode".  (Right-click the HydroCAD icon and select Properties.  Then click the "Compatibility" tab and make sure none of the options are selected.)

    Technical Note: This error indicates that essential information is missing from the Windows registry.  This information is automatically created by the installation program, and is required before HydroCAD can run.  If you still get this error after following the proper installation procedure, your computer may be configured to prevent the creation of new keys in the HKLM section of the registry, or you may have insufficient access rights.  Contact your system administrator for further assistance.

    Error 141: Missing Version or Copyright Information

    The HydroCAD program file is damaged.  To correct the problem, you must run the original HydroCAD setup program.  

    Error 145: Network Files Not Found

    The folder you selected does not contain a network installation of HydroCAD.

    Error 150: Network Files Not Found

    HydroCAD was unable to find the shared network files you previously specified.

  • Click OK to temporarily use local files instead
  • -or- click Cancel to leave HydroCAD.

    This error can occur only if you (or your system administrator) has configured HydroCAD to use shared data files, as specified on the Settings|Network screen.

    To permanently resolve this error, you must:
    1) Restore access to the specified network folder
    2) -or- Open the Settings|Network screen and select a new folder
    3) -or- Open the Settings|Network screen and click "Reset" to use local data files.

    If you specify a network folder, it must contain a complete installation of the same version of HydroCAD you are currently running on your PC.

    Note: This feature is used to share special data files and lookup tables over a network.  It is not used to share HydroCAD license information (which is configured on the Settings|Serial Number screen) or HydroCAD project files (which can be freely stored in any local or network folder).
     

    Error 160: Network Files Don't Match

    The shared network files are not the same version at the as the current HydroCAD program.

  • Click OK to temporarily use local files instead
  • -or- click Cancel to leave HydroCAD.

    This error can occur only if you (or your system administrator) has configured HydroCAD to use shared data files, as specified on the Settings|Network screen.

    To permanently resolve this error, you must:
    1) Update the network installation to match the current program
    2) -or- Open the Settings|Network screen and click "Reset" to use local data files.
     

    Error 170: Cannot write to {file}

     Data could not be written to the specified file.

    The file for folder may be write-protected, or you may not have sufficient access rights.

    Error 180: Unable to connect to xxxxxx

     HydroCAD was unable to connect to a file that is required for AutoCAD communication.  To correct the problem, rerun the HydroCAD setup program and be sure you have selected the version of AutoCAD you intend to use with HydroCAD. If the desired version is not listed, a HydroCAD update may be required.

    Error 181: Unable to run xxxxxx

     HydroCAD was unable to run a specific file that is required for AutoCAD communication. The error message will indicate the exact nature of the failure.

    To correct the problem, rerun the HydroCAD setup program and be sure you have selected the version of AutoCAD you intend to use with HydroCAD. If the desired version is not listed, a HydroCAD update may be required.

    Error 183: AutoCAD Version Mismatch

     The AutoCAD program you are communicating with appears to be the wrong version. To resolve the problem:

    1) Rerun the HydroCAD setup program and select the version of AutoCAD you intend to use. If your AutoCAD version isn't listed, a HydroCAD update may be required.

    2) If the problem persists, manually start the intended version of AutoCAD before starting the communication -or-

    3) Select the desired AutoCAD version on the Import tab of the Watershed Settings screen.

    Error 185: Unable to open drawing

     HydroCAD was unable to open the specified drawing file. The message will contain additional details on the failure.

    If the message indicates that HydroCAD "Cannot find program ID: AutoCAD.Application", make sure you are not running HydroCAD in XP-compatibility mode. (To access the compatibility mode settings, right-click the HydroCAD shortcut and select Properties.)

    Error 186: Layer name not specified

     A required layer name was not specified.   Review the layer assignments on the Settings|Watershed screen and provide the missing information.

    Error 187: Layer does not exist

     A required drawing layer was not found while importing watershed data.  To make sure all required layers exist, open the Settings|Watershed screen and select "Verify Layers".

    Error 188: Invalid Polylines Found

     HydroCAD detected invalid entities on one of the drawing layers while importing watershed data. The invalid entities are highlighted for inspection and correction. Note that some problems can be corrected automatically by selecting "Fix Polylines" on the Settings|Watershed screen. If this error occurs when auto-correction is enabled, you must correct the problem manually before the watershed import can be completed.

    All watershed line-work must have the following characteristics:

    -Must consist of standard or lightweight polylines.
    -Must have at least 3 vertices.
    -Must be closed, even if the first and last vertices coincide.
    -Must not be self-crossing.
    -Cannot include circles or individual line segments.

    When auto-correction is enabled, HydroCAD will close any open polylines by connecting the first and last vertices. Self-crossing of the first and last segments will be corrected by trimming the portion of these segments that extends beyond their point of intersection. Any other errors are not corrected automatically, and will cause the import process to stop if "Check Polylines" is selected.

    Note: Although you can allow the import process to continue in the presence of invalid polylines by deselecting "Check Polylines", this is not recommended since it will allow potentially invalid polylines to be used in the import process, and may generate invalid results.

    Error 189: Watershed import failed

     The watershed import process has failed.  Details will appear in the actual message.

    Error 400: Outdated project file

    This project was created with the HydroCAD 5.91 prototype, which used a preliminary file format that is not supported by later versions of HydroCAD.

  • If the project was imported from HydroCAD-5 (or earlier), you can correct the problem by importing the project again.  Otherwise, you should delete the file.

    Note: Project files are normally upward compatible with all later versions.  It is only the 5.91 prototype format that is incompatible with later versions.
     

    Error 405: Unknown File Extension
    HydroCAD is unable to open the specified file because the file extension is unknown.

    This error should never occur in normal use of HydroCAD.  It probably means that the file extension is not properly configured in Windows, so that HydroCAD is being asked to open a file that should be associated with another application.

    The error can also occur if you run HydroCAD from a command line and include a data file with an incorrect extension, or if you right-click an unknown file type and force Windows to "Open with HydroCAD".

    Note: To open a project file from HydroCAD-5 or earlier, use Project|Import.

    Error 410: Cannot load file

    HydroCAD is unable to load the file because it contains unrecognized data.  The first unrecognized line is displayed.

  • This message can occur if the file is damaged, or if it was created with a newer version of HydroCAD that implements features that are not present in your current version.  While project files are always upward compatible (with newer versions of HydroCAD), they are not necessarily backward compatible.

    If the project was created on another HydroCAD system, compare the version numbers to see if you need to update your program.  Information on the latest update can be found on the HydroCAD web site, or by selecting Help|Check for Update.
     

    Error 420: Cannot lock file

    HydroCAD was unable to lock the project file.

    To ensure exclusive file access, HydroCAD places a full read/write lock of each project file as long as the project is open.  If it is unable to obtain a full lock, the project is closed and this error occurs.

  • If the file is on a read-only medium (such as a CD-ROM) copy the file to a local disk drive where you have full read/write access.
  • Check the file properties by right-clicking the file and selecting "Properties".  Make sure the "Read-only" box is not checked.
  • Make sure the file is not currently open in any program, including HydroCAD.
  • Make sure you have adequate network permissions for the specified file and folder.

    Note: If you transport a file using a CD-ROM or other write-protected media, the file will normally remain read-only even when copied back to a writable media!  After transporting the file, you must remove the read-only file status as described above.
     

    Error 430: Cannot open file

    HydroCAD was unable to open the file.  This can occur if the file is already locked by HydroCAD or by another application, or if an error occurred while reading the file.

  • Make sure the file is not currently open in any program, including HydroCAD.
  • Make sure you have adequate network permissions for the specified file and folder.
     

    Error 440: Cannot open Units Definition

    HydroCAD was unable to open the specified units definition file.

  • If the project uses a standard units definition, the file may have been deleted.  Reinstall HydroCAD to ensure that all required files are present.
  • If the project uses a custom units definition, you must place a copy of the custom file in your HydroCAD program folder.
     

    Error 445: Invalid Units Definition

    HydroCAD was unable to read the contents of the specified units definition file or the custom project units.
     

  • If the project uses a standard units definition, the file may have been damaged.  Reinstall HydroCAD to ensure that all required files are present.
  • If the project uses a custom units definition, the file formatting may be incorrect.  Recheck the file to be sure your changes are consistent with the required format.
  • If the project uses custom project units, verify the units formatting on the Setting|Units screen.
     

    Error: 447 Missing Units Parameter

    HydroCAD could not find a definition for the specified units parameter. The missing parameter will appear in screens and reports with a question mark (?) instead of the correct units. This situation may cause incorrect entry and reporting of the specified parameter, and should be corrected immediately:

    If the project uses a custom units definition file, the file may be outdated, and may not contain new parameters that were added in a subsequent HydroCAD release. To correct this problem and make the file fully portable to any newer version:

    1) Open the Settings|Units screen.
    2) Select one of the standard unit definition files.
    3) Use the Custom button to customize the desired parameter(s).

    If the project already uses one of the standard units definition files, the file may have been damaged. Reinstall HydroCAD to ensure that the correct files are present.

    Error 460: TR-20 Import Failed

    Invalid data was encountered while importing a TR-20 data file.

    This usually indicates a damaged or improperly formatted TR-20 input file.  The error message will indicate the exact reason for the failure.  Correct the file as required.

    For further information read about the TR-20 import procedure.

    Error 500: Invalid Time Span or dt

    The time span settings are invalid.  Select Settings|Calculation and verify the values on the Time Span tab.

    Error 510: Incompatible routing methods

    The reach routing and pond routing methods are not compatible.  You cannot mix different routing methods.

    Select Settings|Calculation and verify the settings on the General tab.

    Error 520: Illegal loop involving xxx

    The routing diagram contains a loop involving the specified node.  Loops are not allowed with dynamic or sequential routing methods, since the routing sequence cannot be determined.

    There are two ways to resolve this situation:

    1) Change the routing so the loop is eliminated.

    2) Switch to a simultaneous routing method, which is able to process loop flows. To change the routing method(s) select Settings|Calculation.

    Error 530: Area required with exfiltration velocity

    The pond's storage data is not sufficient to define the area required by your exfiltration outlet. 

  • If there are no storage definitions (a catch-basin or zero-storage pond) you must set the exfiltration flow directly, or define the exfiltration using a special outlet device.  
  • Make sure at least one storage definition is marked Allow Exfiltration.  Otherwise there will be no area available for exfiltration.
  • If you entered custom stage-storage data,  (1) you must provide surface areas, rather than incremental or cumulative storage values and (2) you may not use a prismatic shape in conjunction with wetted-area exfiltration.
     

    Error 540: Groundwater elevation must be below pervious storage

    The pond's storage volume extends below the groundwater elevation, creating a negative hydraulic gradient from the bottom of the storage to the groundwater, so that exfiltration cannot be calculated based on Darcy's law.

      

    Error 550: Rational intensity or duration missing

    When attempting to perform runoff calculations using the Rational method, the rainfall intensity or duration was not defined.

    Use Settings|Calculation: Rainfall to enter the desired intensity and duration.

    Error 560: Storm depth is zero

    When attempting to perform runoff calculations using the SCS or SBUH runoff method, the storm depth was not defined.

    Use Settings|Calculation: Rainfall to enter the correct depth for your location. If you are using rainfall events, make sure each event has a valid rainfall depth.

    Error 570: Storm duration is zero

    When attempting to perform runoff calculations using the SCS or SBUH runoff method, the storm duration was not defined.

    Use Settings|Calculation: Rainfall to enter the correct rainfall duration.

    Error 580: Back-to-Back storms = zero

    When attempting to perform runoff calculations using the SCS or SBUH runoff method, the number of back-to-back storms was not defined.

    Use Settings|Calculation: Rainfall to enter correct value.

    Error 585: Invalid IDF file

    The contents of the IDF curve file are invalid.

  • If you are using a standard IDF file, the file may have been altered or damaged.  Reinstall HydroCAD to restore the file.
  • If this is a custom IDF file, check the contents of the file to be sure it conforms to the requirements outlined in IDF.txt
     

    Error 590: Invalid rainfall file

    The contents of the rainfall distribution file are invalid.

  • If you are using a standard rainfall distribution, the file may have been altered or damaged.  Reinstall HydroCAD to restore the file.
  • If this is a custom rainfall distribution, check the contents of the file to be sure it conforms to the requirements outlined in Rainfall.txt
     

    Error 595: Rainfall not specified

    No rainfall distribution has been selected for the current project.  Runoff calculations cannot be performed until a rainfall distribution is selected.

  • Open the Settings|Calculation screen, click the Rainfall tab, and enter the desired rainfall settings.

    Tip: You can use the "Calculator" button on the toolbar to go directly to the calculation settings screen.
     

    Error 600: Unable to open rainfall file

    HydroCAD was unable to open the specified rainfall distribution or IDF curve.

  • When using a project imported from an earlier version of HydroCAD, you may need to re-select the rainfall distribution.
  • If you are opening a project created by someone else, they may have used a custom rainfall definition or IDF curve that isn't present on your computer.

    Verify the rainfall selection using Settings|Calculation: Rainfall.  If the project uses a custom rainfall, obtain a copy of the file and place it in the HydroCAD\Rainfall folder or in the same folder as the project file.  (IDF files should be placed in the HydroCAD\IDF folder or in the same folder as the project file.)
     

    Error 610: Invalid Unit Hydrograph file

    The contents of the unit hydrograph data file are invalid.

  • If you are using a standard unit hydrograph, the file may have been altered or damaged.  Reinstall HydroCAD to restore the file.
  • If this is a custom unit hydrograph, check the contents of the file to be sure it conforms to the requirements outlined in UH.txt
     

    Error 615: Unit Hydrograph not specified

    No unit hydrograph has been selected for the current project.  Runoff calculations cannot be performed until a unit hydrograph is selected.

  • Open the Settings|Calculation screen, click the Unit Hydro tab, and select the desired unit hydrograph.

    Tip: You can use the "Calculator" button on the toolbar to go directly to the calculation settings screen.
     

    Error 620: Unable to open Unit Hydrograph file

    HydroCAD was unable to open the specified unit hydrograph data file.

  • If you are opening a project created by someone else, they may have used a custom unit hydrograph file that isn't present on your computer.

    Verify the UH selection using Settings|Calculation: Unit Hydrograph.  If the project uses a custom UH, obtain a copy of the UH file and place it in the HydroCAD\Rainfall folder or in the same folder as the project file.
     

    Error 630: Invalid external hydrograph file

    When a link attempted to read an external hydrograph file, the contents were invalid.

  • If this is a custom data file, verify that it conforms to the required external file format.
     

    Error 640: Unable to open external hydrograph file

    While processing a link, HydroCAD was unable to open the specified external hydrograph file. 

    1) If you're using the link to import a flow from another project: 

  • Make sure the hydrograph export mode in the upstream project is set to "Unrouted Outflows".
  • Make sure the upper project is saved and closed.  Exported hydrographs are not available while the project is open.
  • If either project uses rainfall events, make sure both projects are using the exact same events using Settings|Calculation: Rainfall.

    2) If you're using the link to import a custom hydrograph file:
  • Verify the file selection using Edit|Link: File.
     

    Error 650: External hydrograph not found

    When reading an external data file into a link, the specified hydrograph was not found.

  • Verify the hydrograph selection using Edit|Link: File.
  • If the external data file uses named rainfall events, the current project must use a matching event name.  If the external file was exported by another project, you can copy the required events using the Import button on the Rainfall tab of the Settings|Calculation screen.
     

    Error 660: Invalid geometry

    The geometry for a channel is invalid.  Use Node:Edit to verify and correct the parameters.

    Error 670: Missing or invalid stage data

    The stage data is invalid or doesn't include enough points.  Use Node:Edit to verify and correct the data.

    When defining a reach using a custom rating table or cross-section, data must be provided for at least two unique elevations.

    When using the Muskingum-Cunge routing method, a minimum of three elevations are required in order to calculate the m-value used in the routing procedure.

    Error 680: Routing method not implemented

    The routing method you have selected has not been implemented.

  • Please select another routing method.

    To check for an update that may implement this method, select Help|Check for Update.
     

    Error 690: Discharge extrapolation failed

    When performing a reach or pond routing, the highest defined stage was exceeded, and a declining stage-discharge curve precluded the normal use of extrapolated values.

    To correct the problem, provide storage information for additional stages (higher elevations).

    Error 700: Unable to extend routing tables above xx'

    While performing a pond routing, the water surface elevation has exceeded the expected range.  HydroCAD attempted to extend the routing tables above the initial range, but failed because the storage and/or discharge curves are no longer increasing past the specified elevation.

    This typically occurs because there is no additional storage or discharge capacity available.  This makes it impossible to complete the routing operation.

  • To correct the problem, you must provide additional storage and/or discharge information for higher elevations.
  • To get a better view of your existing data, disconnect all inflows to this node and open the report window.  This will let you verify the current stage-discharge and stage-storage data.
     

    Error 710: Unable to open chamber file

    HydroCAD was unable to open the specified     chamber definition file.

  • If you are opening a project created by someone else, they may have used a custom chamber file that isn't present on your computer.

    Verify the chamber selection on the pond's Storage tab.  If the pond uses a custom chamber definition, obtain a copy of the file and place it in the HydroCAD\Chambers folder or in the same folder as the project file.
     

    Error 720: Invalid chamber definition file

    The contents of the chamber definition file are invalid.

  • If you are using a standard chamber definition, the file may have been altered or damaged.  Reinstall HydroCAD to restore the file.
  • If this is a custom chamber definition, check the contents of the file to be sure it conforms to the requirements outlined in Chambers.txt
     

    Error 730: Embedded storage exceeds outer storage

    The overall volume of all embedded storage is larger than the overall volume of the outer storage definition.

    This error usually results from a data entry error, such as setting an excessive storage multiplier for one of the embedded storage definitions.  Check the storage definitions for the applicable pond.

    If you need help locating the problem, remove all inflows from the applicable pond and open the pond summary report.  Scroll down to the storage table, which will include details on the embedding error.

    Error 740: Projects must use same calculations units

    The project you are attempting to merge uses different calculation units that the current project.

    To perform the merge, you must change the calculation units for one of the projects so that it matches the other.

    1) Open the project whose units you wish to change.  You can change either project, but you may prefer to change the source project.

    2) Select Settings|Units and change the selection under "Calculation Units".  Click OK so save the change.

    3) Save and close the project.  The new setting will take effect the next time the project is opened.

    You can now attempt the merge operation again.  After completing the merge, you may restore the original calculation units, if desired.

    Error 750: Corresponding nodes must be same type

    While merging another project, at least one node was encountered that had the same number but was of a different type.  The operation is automatically canceled without making any changes.  The problematic nodes are selected on the routing diagram.

    When merging projects, nodes are matched based on the assigned node number.  If you intend to use the Project|Merge operation in the future, you must take care to preserve the original node numbering, otherwise data may not be merged with the intended nodes.

    Error 755: Tc procedure not allowed

    The procedure you have selected to calculate the time-of-concentration is not compatible with the current runoff settings.

    For example, the Curve Number method is not allowed when using the Rational method, since the Rational method does not define the required Curve Number.  To use the Curve Number method, you must switch to another runoff method in which the Curve Number is defined.

    Error 760: Reach Slope Required

    The routing calculations cannot be performed because the reach slope is undefined.  This means that the reach inlet and outlet invert are set to the same elevation.  This may occur after importing a TR-20 data file, which does not define a channel slope.

    When using a custom stage-discharge table, the channel slope is required only by some routing procedures, such as the Muskingum-Cunge method.  Other procedures, such as Storage-Indication, can operate without a slope as long as explicit stage-discharge data is provided.

    Error 770: Unable to open Curve Number lookup table
    HydroCAD was unable to open the specified curve number lookup table.  If you are opening a project created by someone else, they may have used a custom lookup table that isn't present on your computer.

    Verify the lookup table selection using Settings|Calculation: Advanced. If the project uses a custom lookup table, obtain a copy of the file and place it in the HydroCAD folder or in the same folder as the project file.

    Error 900: Internal Error

    This message indicates that an unexpected condition has occurred in the program.

    Please record the EXACT message that was displayed, as well as the conditions under which it occurred, and report it to HydroCAD Support.