Saturday, November 13, 2010

Drainage Wells or a Vertical Exfiltration Trench

Subject: Drainage Wells or a Vertical Exfiltration Trench in InfoSWMM
Note, this is just one way to model an Exfiltration Trench. The source for the image below is Rice Creek Watershed.
You can make a storage node to simulate the trench with the following characteristics:
· Functional or Shape Curve to describe the shape of the trench,
· Infiltration parameters to simulate the infiltration flow out of the bottom or sides of the trench,

Step 1: Define the shape and geometrical characteristics of the Infiltration Trench

Step 2: Define the soil infiltration characteristics of the trench

Step 3: Run the simulation. The Storage Volume Summary tells you the volume infiltrated and the average outflow.

Step 4: Output Manager will also show the infiltration outflow, the depth and the volume of the infiltration/storage node.

Step 5: Infiltration losses out the side and bottom of the orifice.

Drainage Wells or a Vertical Exfiltration Trench in InfoSWMM

by dickinsonre
Subject:  Drainage Wells or a Vertical Exfiltration Trench in InfoSWMM

Note, this is just one way to model an Exfiltration Trench.  The source for the image below is Rice Creek Watershed

You can make a storage node to simulate the trench with the following characteristics:

·         Functional or Shape Curve to describe the shape of the trench,
·         Infiltration parameters to simulate the infiltration flow out of the bottom or sides of the trench,



Step 1:  Define the shape and geometrical characteristics of the Infiltration Trench


Step 2: Define the soil infiltration characteristics of the trench


Step 3:  Run the simulation.  The Storage Volume Summary tells you the volume infiltrated and the average outflow.


Step 4:  Output Manager will also show the infiltration  outflow, the depth and the volume of the infiltration/storage node.


Step 4:    Infiltration losses out the side and bottom of the orifice.



Weirs in InfoSWMM and SWMM 5

Subject: Weirs in InfoSWMM and SWMM 5
Figure 1 shows the relationship between the weir input data and the upstream and downstream nodes.
· Height,
· Crest and
· Node Invert Elevation
There are four types of weirs and if the weir becomes submerged downstream the Villemonte weir submergence correction is applied (Figure 2). You can have flow reversal across the weir unless you use a Flap Gate for the weir (Figure 3).


Figure 1: Definition of Weir Terms

Figure 2: Villemonte Weir Submergence Correction

Figure 3: Flow Reversal in a Weir

Weirs in InfoSWMM and SWMM5

by dickinsonre

Weirs in InfoSWMM and SWMM5

Subject: Weirs in InfoSWMM
 Figure 1 shows the relationship between the weir input data and the upstream and  downstream nodes.
·         Height,
·         Crest and
·         Node Invert Elevation
 There are four types of weirs and if the weir becomes submerged downstream the Villemonte weir submergence correction is applied (Figure 2).  You can have flow reversal across the weir unless you use a Flap Gate for the weir (Figure 3). 

Figure 1:  Definition of Weir Terms
Figure 2: Villemonte Weir Submergence Correction
Figure 3:  Flow Reversal in a Weir

Multiple Storm Events in InfoSWMM and How to Use them in the Scenario Manager

Subject: How to make Multiple Storm Events in InfoSWMM and How to Use them in the Scenario Manager
Step 1. Make a new Time Series to hold the data points for your new Rainfall Time Series in the Operation Tab of the Attribute Browser.

Step 2. Populate the Rainfall Distribution with a SCS Type II Hyetograph with a 1 inch rainfall total


Step 3. Now Clone the created Rainfall Distribution and make 10, 25, 50 and 100 year storm events each with 1 inches of rainfall in a cumulative distribution.


Step 4. Now use the Block Edit command and convert each of the newly created hyetographs to 4, 7, 10, 15 and 20 inch cumulative rainfall totals from the original 1 inch rainfall total (for example).

Step 5. Now create a Raingage for each of the newly created hyetograph time series using the DB Editor under the Raingage Table in Hydrologic Data


Step 6. Link the Time Series to the new Raingages and define the type (cumulative), units (inches) and hyetograph interval (15 minutes)

Step 7. Make 4 New Scenarios for the different return period hyetographs, the Base Scenario will use the 5 year or 4 inch SCS II rainfall.

Step 8. Use the DataSet Manager and make 4 new Subcatchment DB Tables in which each Subcatchment Set uses a different return period hyetograph.

Step 9. Run the Batch Simulator for all 5 scenarios including the Base Scenario.

Step 10. You can use the Output Report Manager to see the Rainfall for all of the Batch Runs to check if the proper rainfall was used for each Scenario Simulation.

How to make Multiple Storm Events in InfoSWMM and How to Use them in the Scenario Manager

by dickinsonre
Subject:  How to make Multiple Storm Events in InfoSWMM and How to Use them in the Scenario Manager

Step 1.  Make a new Time Series to hold the data points for your new Rainfall Time Series in the Operation Tab of the Attribute Browser.


 

Step 2.  Populate the Rainfall Distribution with a SCS Type II Hyetograph with a 1 inch rainfall total

 


Step 3.  Now Clone the created Rainfall Distribution and make 10, 25, 50 and 100 year storm events each with 1 inches of rainfall in a cumulative distribution.

 

Step 4.  Now use the Block Edit command and convert each of the newly created hyetographs to 4, 7, 10, 15 and 20 inch cumulative rainfall totals from the original 1 inch rainfall total (for example).


Step 5.  Now create a Raingage for each of the newly created hyetograph time series using the DB Editor under the Raingage Table in Hydrologic Data




Step 6.  Link the Time Series to the new Raingages and define the type (cumulative), units (inches) and hyetograph interval (15 minutes)



Step 7. Make 4 New Scenarios for the different return period hyetographs,  the Base Scenario will use the 5 year or 4 inch SCS II rainfall.



Step 8Use the DataSet Manager and make 4 new Subcatchment DB Tables in which each Subcatchment Set uses a different return period hyetograph.



Step 9. Run the Batch Simulator for all 5 scenarios including the Base Scenario.



Step 10.  You can  use the Output Report Manager to see the Rainfall for all of the Batch Runs to check if the proper rainfall was used for each Scenario Simulation.





Reserve Capacity and Reserve Flow in a Link in InfoSWMM and SWMM 5

Subject: Reserve Capacity and Flow in a Link

The Reserve flow and Reserve Capacity are modeling guidelines and do not actually influence the computed flows in a link. If you have a positive Reserve flow or capacity then you MAY get more flow in the link based on the current flow being less than the Qfull for the link but not if the link is under surcharge, has backwater conditions or has large entrance and exit losses. You cannot always assume that because the Reserve flow is positive the link can handle more upstream flow.

Here are few graphs that show the relationship between Qfull, the actual Q in the link and the Reserve Flow or Reserve Capacity. The Qfull is a reference flow and is not used during the computation in InfoSWMM and SWMM5.

Condition 1: Positive Reserve Flow – the flow is always less than Qfull and the Reserve flow and Reserve Capacity are Positive.

Condition 2: Negative Reserve Flow – the flow is sometimes greater than Qfull and the Reserve flow and Reserve Capacity are negative when this occurs.

Reserve Capacity – the Reserve in the link * the current link volume.

What Node and Link Invert Elevations Does SWMM 5 Use?

Note: What Node and Link Invert Elevations Does SWMM 5 Use?
SWMM 5 uses the following Node information from the user:
· Node Invert Elevation,
· The Node Rim Elevation which is the Node Invert Elevation + the Maximum node depth
· The Ponded Area when the Ponded Area option is used
· The Surcharge Depth above the Node Rim Elevation
SWMM 5 uses the following link information from the user:
· The Link Upstream Offset Depth or Offset Elevation and
· The Link Downstream Offset Depth or Offset Elevation
· The Link Maximum Depth or Diameter
SWMM 5 calculates the following information internally:
· The Pipe Crown Elevation at the upstream and downstream link nodes. The Pipe Crown is the Pipe Diameter + Link Offsets
· The Node Highest Pipe Crown Elevation,
· The Surcharge Depth above the Rim Elevation if the Node has a Surcharge Pressure Depth at the Node during the simulation,
o If the Surcharge Depth is 0 then the program will either lose the flooded water or store the flooded water during the simulation
· The Flooded Depth above the Rim Elevation if the Node uses the Ponded Area Option
o You have to enter a Ponded Area for the node AND use the Global Allow Ponding Option
SWMM 5 Rules for Pipes
· The Pipe Invert Cannot be below either upstream or downstream node invert – the program will print a warning in the rpt file and set the offset to 0 internally,
· The Pipe Crown Cannot be above the Rim Elevation of the Node – the program will raise the Rim Elevation when this happens and print a warning in the rpt file.
The use of Offset Depth or Offset Elevation for the Link Offsets is based on the user choice at the bottom of the SWMM 5 GUI Map.
Or in the Tools/Preference/Operation dialog of InfoSWMM/H20MAP SWMM

Wednesday, November 10, 2010

InfoSewer Static Gravity Main Report

Note: Static Gravity Main Report

Shows steady state simulation results for all gravity mains in tabular format. The report displays one record for each gravity main in the current H2OMAP Sewer project. Gravity main report columns include the Node Identifier, Total Flow, Unpeakable Flow, Peakable Flow, Coverage Flow, Infiltration Flow, Storm Flow, Flow Type, Velocity, d/D, q/Q, Water Depth, Critical Depth, Full Flow, Coverage Count, Backwater Adjustment, Adjusted Depth and Adjusted Velocity.
The following variables are displayed on the Static Gravity Main Report in the Output Report Manager for all or selected gravity mains:
1. ID - Gravity main identifier.
2. From Node - ID of upstream node.
3. To Node - ID of downstream node.
4. Diameter - Inside pipe diameter for circular channels, in (mm).
5. Channel Depth - Maximum depth of a conduit (for non-circular channels only), in (mm).
6. Channel Width - Top/Bottom width of a conduit (for non-circular channels only), in (mm).
7. Channel Left Slope - Left side slope of a conduit (for trapezoidal and triangular channels only).
8. Channel Right Slope - Right side slope of a conduit (for trapezoidal and triangular channels only).
9. Length - Pipe length, ft (m).
10. Slope - Ratio of the change in vertical distance to the change in horizontal distance, unitless.
11. Total Flow - The summation of all flow types, flow unit.
12. Unpeakable Flow - The flow to which no peaking is applied, flow unit.
13. Peakable Flow - The flow derived based on the Federov peaking equation, flow unit.
14. Coverage Flow - The flow derived based on the Harman and Babbitt peaking equation in reference to the contributing population, flow unit.
15. Infiltration Flow - The volume of groundwater entering the sewer system from the soil through defective joints, broken or cracked pipes, improper connections, or manhole walls, flow unit.
16. Storm Flow - Peak storm load in the pipe, flow units.
17. Flow Type - Indicates if the flow is pressurized or free surface.
18. Velocity - The speed with which the water is traveling through the pipe, in ft/s (m/s).
19. d/D - The ratio of actual flow depth to the diameter of the pipe (full flow depth), unitless.
20. q/Q - The ratio of actual flow to the full flow as derived based on Manning's Equation, unitless.
21. Water Depth - The depth of water as it is flowing through the pipe, ft (m).
22. Critical Depth - The depth of water resulting when the Froude Number is equal to 1.0, ft (m).
23. Full Flow - The capacity of the pipe as evaluated based on Manning's Equation (when d/D = 1.0), flow units.
24. Coverage Count - The population parameter used in the Harman and Babbitt equations.
25. Backwater Adjustment If the downstream head of the link is greater than the flow depth + the downstream pipe invert then the adjusted depth is one half of the sum of the water surface depth at the upstream and downstream ends of the link.
26. Adjusted Depth – The adjusted depth is the average of the upstream plus the downstream adjusted depth, where the upstream adjusted depth is the upstream head minus the upstream pipe invert elevation and the downstream adjusted depth is the downstream head minus the downstream pipe invert elevation. The adjusted depth is the minimum of the pipe diameter and the computed pipe adjusted depth.
27. Adjusted Velocity – the adjusted depth is used to calculate the wet area and adjusted velocity = flow/wet area.

InfoSewer Static Loading Manhole Report

Note: Static Loading Manhole Report

Shows steady state simulation results for all manholes in tabular format. The report displays one record for each manhole in the current H2OMAP Sewer project. Manhole report columns include the Node Identifier, Rim Elevation, Load, Overload and Grade, surcharge status, occurrence of a hydraulic jump across the node and the unfilled and surcharged depth.

The following variables are displayed on the Static Loading Manhole Report in the Output Report Manager for all or selected manholes:

1. ID - Manhole node identifier.

2. Rim Elevation - Manhole node elevation, ft (m).

3. Base Flow - The base loading applied to the manhole (before peaking), flow units.

4. Total Flow - The calculated flow (after peaking), inserted into the manhole, flow units.

5. Storm Flow - Peak storm load at the manhole, flow units

6. Grade - Manhole node hydraulic grade for the steady state simulation, ft (m).

7. Status - Surcharge status of the manhole.

8. Hydraulic Jump – Was there a Hydraulic Jump between the incoming and outgoing pipe of the node?

9. Unfilled Depth – depth between the node Rim Elevation and the Node Grade. A zero value indicates it is full.

10. Surcharge Depth - is the difference of “The Depth of Water of Manhole” and “The Crown of the Highest Connecting Conduits”. A positive Surcharge Depth means the node water surface elevation is above the highest pipe crown, a negative depth means that the node depth is below the highest pipe crown.

RDII Import into InfoSWMM

Note: InfoSWMM and H2OMAP SWMM can import any version of the RDII Unit Hydrograph data from SWMM 5.0.001 to SWMM 5.0.021 using the Import manager command. The difference is that SWMM 5.0.013 and earlier versions had less initial abstraction data and versions after SWMM 5.0.014 had more initial abstraction data. However, the Import Manager detects the version and imports the data correctly. SWMM 5.0.013 stored 9 RTK and 3 Initial Abstraction parameters and later versions 9 RTK and 9 Initial Abstraction parameters. InfoSWMM will import any format into the current version of InfoSWMM or H20MAP SWMM, which is based on SWMM 5.0.018 but will soon be based on SWMM 5.0.021.

SWMM 5.0.001 to 5.0.013 RDII UH Data

SWMM 5.0.014 to 5.0.021 RDII UH Data

InfoSWMM and H2oMAP SWMM will have 9 RTK and 9 Initial Abstraction Parameters.

How to Import Subcatchments from GIS into InfoSWMM

Note: How to Import Subcatchments from GIS into InfoSWMM
Step 1: Add your shapefile using the Add Data command.
Step 2: Your imported shape file has no subcatchment data before we initialize the project.
Step 3: Add your subcatchment data using the GIS Exchange Cluster Import
Step 4: Now you have the Subcatchments in the DB Tables and can now calculate the area.
=====================================
Step 1: Add your shapefile using the Add Data command.


Step 2: Your imported shape file has no subcatchment data


Step 3: Add your subcatchment data using the GIS Exchange Cluster Import

Step 4: Now you have the Subcatchments in the DB Tables and can now calculate the area.

We still have to enter 1/10000 to get the right units for subcatchment area using the Auto Area Calculation under Tools preferences. You first import the shape file and then you turn on Auto Area Calculation, enter a value for the Area Scaling Factor and then use the tool Utilities, Update DB from Map, All Subcatchment to get the Subcatchment Area in hectares.

Tuesday, November 9, 2010

A workaround for Hydrology only models that send all subcatchment flow to the pervious area.

Note: A workaround for Hydrology only models that send all subcatchment flow to the pervious area. Briefly, v16 had a total infiltration of 14 inches in the attached model but v21 has a total infiltration of 3.5 inches. The input file uses the attached rainfall file and it routes all of the flow to the pervious area of the subcatchment. If you plot the losses in v16 and v21 you will see that the losses stop after about 30 days in v21 and continue in v16. I found that if you put in a small evaporation rate (0.01 inches/day will do) then v21 will duplicate the answers of v16. Looking at the depths in the subcatchment it seemed in v21 without evaporation that the depth in pervious area was stuck at the depression storage value.

In summary – the problem seems to be that the losses stop after the depth in the pervious area is above the depression storage unless you have evaporation to sort of kick start the infiltration losses again.


Friday, November 5, 2010

Tuesday, November 2, 2010

Source Node Tracing In InfoSWMM

Note: Source Node Tracing in InfoSWMM. Often you want to know how much flow is being contributed to the flow in a node or link from a single source node. You can use the Trace with Source Node ID option under the Quality Tab of the Run Manager to select the trace node of the analysis. The source node will have a concentration of 100 for all dry weather and wet weather inflow. This includes runoff, RDII inflow, DWF and Inflow Time Series. The InfoSWMM water quality routing routine will then be used to route the source concentration of 100 throughout the whole network. Later using the Report Manager you can view the source node concentration for any set of nodes and links in your network. For example, a concentration of 40 percent means that 40 percent of the flow in the node or link comes from your designated source node (see below).

Monday, November 1, 2010

The new features in SWMM 5.0.021

Note: The new features in SWMM 5.0.021, which really are the new features in SWMM 5.0.019, 5.0.020 and 5.0.021 because of the way in which it was released. The big structural changes were made to the subcatchment, node, groundwater, infiltration and evaporation routines so that there is better continuity between the rainfall that falls on the pervious area of a watershed, the BMP/LID’s of the subcatchment (unlimited per subcatchment), evaporation, infiltration and storage nodes/ponds/lakes. A watershed or subcatchment is now simulated in layers:

· Pervious and Impervious Area surface runoff,

· Shallow Water Aquifer for Infiltration,

· Surface ponds with evaporation and infiltration,

· BMP and LID coverage under the pervious area,

· Two layer Groundwater Aquifer for flow to canals and manholes.

AI Rivers of Wisdom about ICM SWMM

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