Storm And Sanitary Error Messages

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 Original Author:Bentley Technical Support Group










This TechNote provides a list of notes, errors, and warning messages often seen in the InRoads Storm & Sanitary program.


1.)  NOTE: Gutter flow from the downstream bypass is determined from the downstream inlet's basin flow. It does not include any flow bypassed to the downstream inlet.

This is a warning that if an Inlet is receiving bypass flow from downstream, it is only considering the portion of flow from that inlet that came from the Area runoff to the inlet, and does not include any portion of flow that came from bypass flows from other inlets.

For example, lets imagine a network that starts at inlet A, then flows down to B then to C, then to D, etc…  Because of the surface topography, the bypass flow from D goes to C, and whatever C can’t intercept it goes to B, etc…When InRoads calculated the total flow going into inlet B, it takes the area flow from the area attached to B and adds the bypass flow from C (if the users says Yes to redesign for flows from downstream).  The bypass flow considered from C to B only includes the portion from the area attached to C, and does not include any bypass from D (or from any other inlets that may have sent their bypass to C. 

Therefore, there could be some amount of flow that is unaccounted for, since the program will only make one pass down the network, with the option to redesign an upstream structure if bypass is sent to it.

2.)  (Alternate HGL and EGL Used)

The alternate HGL is the EHGL referenced in Step 3, case 2 in the HEC-22 procedures for calculating the EGL.  “If the TW at the conduit is less than (dc+D)/2, the EGL will be the HGL plus the velocity head for the conduit Flow conditions.  The equivalent hydraulic grade line, EHGL, will be the invert plus (dc+D)/2.”

You can review this step in the HEC 22 Urban Drainage Design Manual 2001 Section 7.5, or in the Storm & Sanitary Help in the Design Procedures under “Analysis”.

3.)  No Surface Runoff to Inlet

No flow from an attached area or from injected flow.  No analysis or resizing is done to inlet.

4.)  No Flow Found Upstream/No Flow in Structure

There is no flow coming to this structure from any of the attached upstream structures.

5.)  >maximum table size (Used x.xx)

If a structure is set to resize, and flow exceeds the capacity of structures in the structures DAT file, the largest structure will be used and this message reported to the user.

6.)  Spread is greater than maximum spread (x.xx ft)

Calculated spread at the inlet is greater than the maximum spread specified in Tools>Drainage>Options>Gutter Section tab.

7.)  Pipe Too large for valid connection to inlet

The diameter of the pipe attached to the current inlet exceeds the Max Pipe on Length or Max Pipe on Width value stored in the structures DAT file for that inlet.

8.)  Inlet forced to capture all flow, ignoring capacity calculations

The toggle for “Capture all flow to Inlet, ignoring Inlet capacity calculations” is turned ON in the Design Network dialog.

9.)  Water Depth in Gutter is greater than curb height plus depression (x.xx ft)

The depth of water in the gutter at the current inlet exceeds the maximum value specified in the “Curb Height” field in Tools>Drainage Options>Design Tab for Inlets.  This means water is overtopping the curb.

10.) Unable to design.  Gutter has zero slope.

Either the longitudinal or transverse slope is set to 0% for the current inlet, or the depression is set to 0.  This will halt the network design.

11.) Negative pipe slope.  unable to resize

The current pipe has a negative slope.  The pipe will be analyzed, but not resized.

12.) Minimum height criteria used/ Maximum height criteria used. Pressurized

The flow in the current pipe is low enough or is high enough to use the minimum/maximum pipe size specified in Tools>Drainage>Options>Design Tab for Pipes.

13.) Full flow velocity is greater than maximum (x.xx)/Full flow velocity is less than minimum (x.xx)

The flow in the current pipe has exceeded the value specified for Maximum/Minimum velocity on the Tools>Drainage>Options>Design Tab for Pipes.  Also, if the current pipe is not flowing under full flow conditions, this message will still be issued if the velocity limits will be exceeded under full flow conditions.  This warning is useful because the initial analysis used to size the pipes does not take into account the tailwater affects on the system, since the HGL/EGL calculations occur after the flow analysis and structure sizing.

14.)  “SuperCrt” in Table B of the Design Log

This notes that no losses will be calculated for the current pipe per Step 5D in the HEC-22 procedures for calculating the EGL.  This states that “Pipe losses in a supercritical pipe section are not carried upstream.  Therefore, enter a zero (0) in Column 7B for this structure.”  

You can review this step in the HEC 22 Urban Drainage Design Manual 2001 Section 7.5, or in the Storm & Sanitary Help in the Design Procedures under “Analysis”.

15.) Warning-System surcharged at …

The HGL calculated for the specified inlet/manhole is greater than the rim elevation.

16.) Bypass flow found from a downstream structure.  Do you want to redesign to account for this flow?

As the Network Design command process down the network analyzing/resizing structures, the current structure has a Bypass ID specified that is an inlet that has already been designed, upstream from the current inlet.  This can be due to the surface topography running counter to the slope of the network.

If the user says No, the structure is not redesigned and the flow is no accounted for.  If the user says Yes, the upstream structure is redesigned with the greater amount of flow.

17.) Cover is less than minimum

During the layout of a pipe, the invert and size being placed compared to the active DTM violate the Minimum Cover specified in the Tools>Drainage>Options>Pipes Tab

18.) Slope outside specified range

During the layout of a pipe, the Invert In/Invert Out elevations and slope value violate the Minimum or Maximum Slope value specified in the Tools>Drainage>Options>Pipes Tab

19.) Pipe invert below junction

The current Invert In or Invert Out elevation of the pipe to be laid out is lower the existing invert of the junction the pipe will be connecting to.  Continuing the lay out the pipe will lower the invert of the junction.

20.) Elevation not within range of upstream/downstream structure. Continue?

When attaching a pipe to a inlet or manhole, the current Invert In/Invert Out elevation will cause a violation of the “Maximum Depth” value stored on each inlet/mh.  This value initially comes from  Tools>Drainage Options>Inlet tab or Manhole tab when the structure is laid out.

21.) Time of Concentration outside of table.

The current time of concentration specified is not with range of the durations in the current IDF file specified in File>Project Defualts.

22.) Cannot project all structures selected for profile.

When Drainage Network Reference on the Source leaf in the Create Profile command is set to Alignment or Existing Profile, the stationing of the structures will be relative to the horizontal alignment.  This error message occurs if a structure can not project to the alignment.  This can be caused by 1) the network extends beyond the beginning or the ending of the alignment, 2)a pipe, such as a cross drain pipe, runs exactly perpendicular to the alignment 3)the network ‘double backs’ on itself relative to the stationing of the alignment (i.e. more than one structure can project to the same station)

23.) Channel/Culvert too small for upstream culvert/channel.

When the bottom width of a channel is less than the width of the culvert to which it is attache d, this message will be issued.

24.) Depth is greater than maximum depth.

The Depth of Flow in a channel is greater than the Maximum Depth set for the channel.  This value is set on the Channel tab in the Edit/Review command for channels.

25.) Headwater criteria can not be satisfied.

The tailwater value (entered in the Tailwater field of the Edit/Review Culvert - Culvert tab) is too large and causes the program to be unable to calculate a headwater depth using the culvert analysis equations, OR, the caclulated headwater violates the Maximum Headwater setting in Tools>Drainage>Options>Design tab for Culverts.

26.) Headwater exceeds maximum depth of upstream channel.

The headwater calculated for the current culvert violates the Maximum Depth set for the channel. This value is set on the Channel tab in the Edit/Review command for channels.

27.)  Design Criteria can not be satisfied.

The analyzed culvert violates either the Maximum Barrels or Maximum Outlet Velocity set in Tools>Drainage>Options>Design tab for Culverts.


See Also

Product TechNotes and FAQs

InRoads Product TechNotes FAQs And Support Video Clips

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

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