Drainage Variables
AREA
Area-ID: Drainage area name/identification stored in the drainage database (gdf file)
Area – Description: Drainage area user provided description.
Area - Time of Concentration: User provided or calculated time of concentration.
Area - Tc Used: Time of concentration used in the calculation for the drainage area discharge.
Area – Discharge: Computed discharge for the drainage area.
Area – Intensity: Intensity rainfall used as computed from the time of concentration and rainfall library.
Area - Composite C Value: Calculated composite C coefficient for the Rational method.
Area - Composite Area: Calculated composite area value for the Rational method.
Area - Total Subarea C Value: Calculated composite C value for only the delineated subareas.
Area - Total Subarea: Sum of the delineated subareas only.
Area - Remainder C Value: C coefficient of the area not included into the delineated subareas.
Area - Remainder Area: Calculated value equal to Total Drainage Area minus the Total Subareas.
Area - Subarea 1…20 Area: Area value of the 1..20 delineated subarea.
Area - Subarea 1…20 C Value: C coefficient of the 1..20 delineated subarea.
Area - Subarea 1…20 Description: Description of the 1..20 delineated subarea.
NODE
Node-ID: Drainage node name/identification stored in the drainage database (gdf file)
Node – Description: Drainage node user provided description.
Node – Type: Node type as defined in the drainage library. E.g. curb, grate, junction, other, curb-grate, headwall.
Node - Library Item Name: Node name as it is stored in the drainage library.
Node - Library Item Description: Node description as it is stored in the drainage library.
Node - Reference Chain: GEOPAK chain used to locate the node by station.
Node - Reference PGL: GEOPAK profile used to compute the elevation and longitudinal slope for the node.
Node - Reference TIN: GEOPAK DTM file used to compute the elevation of the node.
Node - Station : Station value computed at the node location using the Node - Reference Chain.
Node - Offset : Offset or distance value computed from the Node - Reference Chain to the node location. A negative value will indicate the left side of the chain.
Node - Location X Node/ Node - Location Y Node : Coordinate location of the drainage node.
Node – Rotation Node: Angle value in which the node is rotated.
Node - Cumulative Tc : Accumulated time of concentration at the node location.
Node - Supplied Discharge: Applied flow into the node. A discharge is entered directly without a drainage area definition.
Node - Cumulative Supplied Q : Accumulated directly-entered discharge in the node.INLET 12-28 2011 Bentley Systems, Incorporated VDOT GEOPAK Drainage
Node – Freeboard : Distance computed as node elevation minus hydraulic grade line elevation.
Node - Cumulative Discharge : Accumulated discharge/flow in the node.
Node - Cumulative Area : Accumulated drainage area in the node.
Node - Cumulative C Value : Accumulated C coefficient in the node.
Node - Cumulative Intensity: Accumulated intensity in the node.
Node - Hyd Center X / Node - Hyd Center Y : Coordinate location of the node hydraulic center.
Node - Elev Point X / Node - Elev Point Y : Coordinate location of the node elevation point .
Node - Origin X / Node - Origin Y : Coordinate location of the node cell origin.
Node - Minimum Depth / Node - Maximum Depth: Distance measured from the node elevation point. These distances paired with the next connected node creates en envelope in which the links can be placed.
Node – Depth : Distance computed from the node elevation point minus the node bottom elevation.
Node - Minimum Invert Elevation : Minimum invert elevation computed from the links arriving or leaving the node.
Node - Maximum Rise In : Maximum link size arriving into the node.
Node - Maximum Rise Out: Maximum link size leaving the node.
Node - Minimum Invert In / Node - Minimum Invert Out : Minimum invert elevation of the links arriving or leaving the node.
Node - Bottom Name : Name as stored in the drainage library of the bottom structure attached to the node.
Node - Bottom Description : Description as stored in the drainage library of the bottom structure attached to the node.
Node - Pay Item : D&C Manager item ID attached to the node.
Node - Bottom X / Node - Bottom Y : Coordinate location of the bottom structure attached to the node.
Node - Bottom Station: Station value computed at the bottom of the structure attached to the node using the Node - Reference Chain.
Node - Bottom Offset: Offset or distance value computed from the Node - Reference Chain to the bottom of the structure attached to the node . A negative value will indicate the left side of the chain.
Node - Bottom Elevation: Elevation of the bottom of the structure attached to the node.
Node - Sump Depth: Extra depth specified by the user added after computing the node bottom elevation.
Node - Is Link Base Flow: Returns a value of -1 if a Baseflow (offsite drainage discharge) option is added to the node.
Node - Link Base Flow Type: Returns a value of 1 if the Baseflow (offsite drainage discharge) is entered as a numeric value. Returns 0 if the baseflow discharge is entered as a predefined drainage area.
Node - Link Base Flow Area: Returns the name or ID of the drainage area entered as baseflow. Returns N/A if not.
Node - Link Base Flow Discharge: Returns the numeric value entered as baseflow discharge. Returns N/A if not.
INLET
Inlet - ID: Drainage inlet name/identification stored in the drainage database (gdf file).INLET VDOT GEOPAK Drainage 2011 Bentley Systems, Incorporated 12-29
Inlet – Description: Drainage inlet user provided description.
Inlet - By Pass Node ID : Node name in which by pass flow is directed from the present inlet.
Inlet – Type: Inlet type as defined in the drainage library. E.g. curb, grate, curb-grate.
Inlet - Profile Type : Inlet placement profile condition. Either On Grade or Sag.
Inlet – Discharge : Inlet computed discharge from the drainage area or supplied discharge.
Inlet – Capacity : Capacity of the inlet based on their physical properties and placement conditions.
Inlet - Max By Pass: Maximum by pass flow/discharge assigned to the inlet as a query value. It is not used for design purposes.
Inlet - By Pass Flow: Computed flow that the present inlet will bypass due to lack of capacity.
Inlet - By Pass Flow Into: Inlet name in which by pass flow is directed from the present inlet.
Inlet - Curb Length: Curb length as defined in the drainage library.
Inlet - Curb Depression: Curb Depression as defined in the drainage library.
Inlet - Curb Height: Curb Height as defined in the drainage library.
Inlet - Curb Depression Width: Curb Depression Width as defined in the drainage library.
Inlet - Slot Length: Slot Length as defined in the drainage library.
Inlet - Slot Width: Slot Width as defined in the drainage library.
Inlet - Grate Type: Grate Type as defined in the drainage library.
Inlet - Grate Length: Grate Length as defined in the drainage library.
Inlet - Grate Width : Grate Width as defined in the drainage library.
Inlet - Grate Area: Grate Area as defined in the drainage library.
Inlet Grate Perimeter: Grate Perimeter as defined in the drainage library.
Inlet - Grate Clog Area: Grate Clog Area as defined in the drainage library.
Inlet - Grate Clog Per Inlet: Grate Clog Per Inlet as defined in the drainage library.
Inlet - Max Ponded Depth: Maximum allowed spread depth. This is used a query value and not for design purposes.
Inlet - Max Ponded Width: Maximum allowed spread width. This is used a query value and not for design purposes.
Inlet - Longitudinal Slope: Slope along the direction of stationing defined by the user or a GEOPAK profile.
Inlet - Computed Ponded Width: Computed spread width.
Inlet - Computed Ponded Depth: Computed spread depth.
Inlet - Right Spread Intercept: : Computed spread width at the right side of the inlet.
Inlet - Left Spread Intercept: Computed spread width at the left side of the inlet.
Inlet - Length Required: Computed inlet required in order to handle all the discharge.
Inlet - Spread N: Manning’s coefficient for the spread section.
Inlet - Composite Spread Slope: Composite slope across the inlet.
Inlet - Inlet to Gutter Offset: Distance applied when the inlet is set at a certain offset of the section considered for computing spread width and depth.LINKS 12-30 2011 Bentley Systems, Incorporated VDOT GEOPAK Drainage
Inlet - Spread Slope 1…5: Slope of the different segments of the Spread Criteria cross section. Section 1 is the closest to the inlet.
Inlet - Spread Width 1…5: Width of the different segments of the Spread Criteria cross section. Section 1 is the closest to the inlet.
LINKS
Link – ID: Drainage link name/identification stored in the drainage database (gdf file).
Link – Description: Drainage link user provided description.
Link – Type: Link type. Either pipe or ditch.
Link - Upstream Node: Upstream node ID of the connecting link.
Link - Downstream Node: Downstream node ID of the connecting link.
Link – Shape: Link shape as defined in the drainage library. E.g. Arch, box, circular, ellipse or pipe arch.
Link – Material: Link material as defined in the drainage library. E.g. aluminum, concrete, plastic, or steel.
Link - Corr – Type: Link corrugation or type as defined in the drainage library. E.g. Standards, low profile, high profile, horizontal, or vertical.
Link - Library Item: Link name as it is stored in the drainage library.
Link - Number of Barrels: Number of parallel pipes going from one node to another.
Link - Actual Length: Link length measured from the graphical ends of the element.
Link - Hydraulic Length: Link length measured from hydraulic center to hydraulic center of each node.
Link - Manning's N Value: Manning’s coefficient of the link.
Link – Slope: Link slope in percentage.
Link – Rise: Link rise in feet or meters.
Link – Span: Link span in feet or meters.
Link – Discharge: Link discharge/flow.
Link - Uniform Depth: Flow uniform depth at the link.
Link - Uniform Velocity: Uniform velocity computed at the link.
Link - Critical Depth: Critical depth computed at the link.
Link - Critical Velocity: Critical Velocity computed at the link.
Link - Friction Slope: Friction slope computed at the link.
Link - Critical Slope: Computed slope caused by critical flow at the link.
Link - Actual Depth Downstream: Downstream runoff depth at the link.
Link - Actual Depth Upstream: Upstream runoff depth at the link.
Link – Capacity: Link capacity under the present physical conditions.
Link - HGL Downstream/ Link - HGL Upstream: Hydraulic grade elevation at the link ends.
Link - EGL Downstream/ Link - EGL Upstream: Energy grade line elevation at the link ends.
Link - Upstream Junction Loss: Junction loss value at the upper portion of the link.
Link - Soffit Upstream /Link - Soffit Downstream: Soffit or crown elevation at the link ends.LINKS VDOT GEOPAK Drainage 2011 Bentley Systems, Incorporated 12-31
Link - Invert Upstream/Link - Invert Downstream: Invert elevation at the link ends.
Link - Minimum Rise: Minimum link rise used for design purposes.
Link - Maximum Rise: Maximum link rise used for design purposes.
Link - Minimum Slope/ Link - Maximum Slope: Minimum/maximum slope at which links would be placed.
Link - Minimum Velocity/Link - Maximum Velocity: Minimum/maximum velocity at which links would be placed.
Link - Design Size: Return a Yes/No value if GEOPAK Drainage will design the size of the links.
Link - Design Barrels: Return a Yes/No value if GEOPAK Drainage will consider parallel links from node to node.
Link - Actual Velocity Downstream/Link - Actual Velocity Upstream : Velocities computed at the link ends.
Link - Pay Item: ID of the Design and Computation Manager item associated with the link as defined in the drainage library.
Link - Library Description: Link description as it is stored in the drainage library.
Link - Iterative Velocity: Computed velocity at the link after 10 iterations.
Link - Full Velocity: Computed velocity assuming that the links are flowing full.
Link - Upstream Freeboard: Computed elevation from the upstream node minus the assigned freeboard to the node.