Demand Area Data Fields

Demand Area ID

Unique text value identifying the Demand Area (usually related to node area codes)

YES

YES

1

30

wn_demand_area

area_id

Text

Polygon ID

Text field linking the Demand Area to Polygons

YES

YES

1

30

wn_demand_area

polygon_id

Text

Calibration Start

The Start Date and Time for the 24 hour period over which Demand Area Analysis calculations will be carried out. The default setting is the Control Start time.

YES

YES

1

wn_demand_area

calibration_start

Total Inflows

Read only value. The inflow into the Demand Area over 24 hours starting from the Calibration Start time (calculated from Live Data).

NO

YES

1

2

WN_VO

wn_demand_area

total_inflows

Double

Total Outflows

Read only value. The outflow from the Demand Area over 24 hours starting from the Calibration Start time (calculated from Live Data)

NO

YES

1

2

WN_VO

wn_demand_area

total_outflows

Double

Net Inflow

Net inflow into the Demand Area.

Net Inflow = Total Outflows - Total Inflows

NO

YES

1

2

WN_VO

wn_demand_area

net_inflow

Double

Length of Mains

Read only value calculated from the total length of mains in the Demand Area (defined by the boundary conditions and seed node(s) on the Demand Area Definition Page)

NO

YES

1

2

L

wn_demand_area

length_of_mains

Double

Unprofiled Demand

Name of the Demand Diagram Category for this Demand Area which will represent unknown demand (e.g. domestic). The Demand Category profile may be updated / created at the end of the flow balance.

YES

YES

1

30

wn_demand_area

unmetered_demand

Text

Demand Interpolation

The point in each timestep where demand is calculated.

Default is Middle

YES

YES

1

wn_demand_area

demand_interpolation

Integer

1

AZNP Node

Average Zone Night Pressure Node is the node with an elevation closest to the average elevation of all nodes in the Demand Area

OR

If Customer Points are available, the nearest elevation to the average elevation of all the Customer Points.

Note: The procedure to determine the AZNP Node does not take account of either Node or Customer Point density.

YES

YES

1

30

wn_demand_area

aznp_node

Text

AZNP

Average Zone Night Pressure calculated from either simulation results or Live Data over the time interval between the NFM Start Time and NFM End Time.

Default value is calculated from Live Data if there is live data associated with the AZNP Node.

Default value is calculated from simulation results if there are simulation results open in the GeoPlan. (Live data will be used if both Live Data and results are available for the AZNP node).

Default value is null if there is no AZNP node specified, or if there are no live data or simulation results available for the AZNP node.

YES

YES

1

2

WN_P

wn_demand_area

aznp

Leakage Profile

Name of the Demand Diagram Category for this Demand Area which will represent leakage. Values from this category will be used in the flow balance calculations.

Default is CONST_LEAKAGE

YES

YES

1

30

wn_demand_area

leakage_profile

Text

Leakage Application

Method used to distribute leakage consumption across the Demand Area.

There are four options available:

Node

All nodes share an equal proportion of leakage consumption.

Leakage applied to node is calculated as:

Length of Pipe

Leakage is applied to nodes based on the length of mains associated to each node. Each node has half the length between itself and the adjoining node associated with it.

Leakage applied to node is calculated as:

Unprofiled Demand

This option divides leakage between all nodes in the Demand Area which have Unprofiled Demand category demand assigned. Demand is weighted by number of properties found at nodes with Unprofiled Demand category.

Total Connections

This option weights leakage at nodes based on the number of connections at the node.

Leakage applied to node is calculated as:

YES

YES

1

wn_demand_area

leakage_application

Integer

Seed Nodes

The Seed Node(s) is a node within the current Demand Area. A trace is carried out starting from the Seed Node and continuing until each branch of the trace reaches either one of the boundary conditions selected in the Boundary Condition grid, or the limits of the network. The resultant selection of nodes and links defines the Demand Area

NO

YES

2

wn_demand_area

seed_nodes

Array

wn_seed_nodes

Bounding Links

Links acting as boundary conditions to the Demand Area

YES

YES

2

wn_demand_area

bounding_links

-1

NFM Start Time

The start time of the period in which the Minimum Night Flow will be calculated.

Default is 00:00

YES

YES

3

wn_demand_area

nfm_start_time

NFM End Time

The end time of the period in which the Minimum Night Flow will be calculated.

Default is 05:00

YES

YES

3

wn_demand_area

nfm_end_time

Measurement Period

The time interval over which the Minimum Night Flow will be calculated

Default is 60 mins

YES

YES

3

WN_TS

wn_demand_area

measurement_period

Integer

60

Min Night Flow Time

Time at which Minimum Night Flow occurs.

YES

YES

3

wn_demand_area

min_night_flow_time

Multiplier

Sampling Duration Correction factor to allow for changes in the Minimum Night Flow Measurement period.

Default is interpolated from the values in table above (from WRc Managing Leakage Reports, Report E - Interpreting Measured Night Flows)

YES

YES

3

2

wn_demand_area

multiplier

Night Use

The demand used for the unprofiled consumer in the leakage calculations

Table from WRc Managing Leakage Reports, Report E - Interpreting Measured Night Flows

Default is 1.7 l/prop/hr

YES

YES

3

2

WN_QNS

wn_demand_area

unmetered_dom_nu

Infrastructure Correction Factor

A factor indicating the relative condition of the infrastructure. Range is expected to be between 0.1 and 2 where:

Default value is 1.

YES

YES

8

1

wn_demand_area

icf

1.0

0.1

2

Pressure Correction Factor

A factor to correct the AZNP to a standard 50m. Range is expected to be between 0.1 and 3.

Default value is calculated from Pressure Correction Factor Method used, if there is an AZNP value available for calculations.

Default value is 1 if there is no AZNP value available for calculations.

YES

YES

8

3

wn_demand_area

pcf

1.0

0.1

3

Leakage Index Method

Method used to calculate the Pressure Correction Factor.There are two options available:

Default is WRC Report 26

YES

YES

8

wn_demand_area

pcf_method

Integer

Target Points

Grid view of Target Points that may be used to define nodes or customer points for level of service monitroing. These points can be selected manually, or they can be generated automatically based on either snap shot pressure results or elevations. See Demand Area Target Points Page for details

NO

YES

9

wn_demand_area

target_points

Array

wn_target_points

PMA Seed Links

Grid of seed links for the current Pressure Managed Area

NO

YES

10

wn_demand_area

pm_area_supplies

Array

wn_pm_area_supplies

Pressure Managed Areas

Grid View of Pressure Managed Areas in the current Demand Area

NO

YES

10

wn_demand_area

pm_areas

Array

wn_pm_areas

Notes

You can keep freeform notes about any object in your network. The notes field can be up to 64,000 characters in size, or about 10 pages of printed text.

NO

YES

11

0

wn_demand_area

notes

Memo

Validation

Indicates the status of the Demand Area Analysis.

NO

YES

NO

wn_demand_area

validation

Integer

Measurement Period Start Time

The calculated start time on the Measurement Period for Minimum Night Flow.

NO

7

Measurement Period End Time

The calculated end time on the Measurement Period for Minimum Night Flow.

NO

7

Adjusted Average Minimum Night Flow

The calculated average Minimum Night Flow for the Measurement Period taking the Multiplier into account.

YES

7

Unprofiled Demand Properties

Count of all properties in the Demand Area using the Unprofiled Demand category.

YES

7

Demand from Known Profiles

Total demand for all Demand Categories used in the Demand Area that are not described as Leakage Profile or Unprofiled Demand on the Parameters Tab.

NO

7

Unaccounted for Water

Calculated Leakage.

YES

7

Leakage Profile Factor

Average Factor taken from the Demand Diagram for the Leakage Category over the measurement period.

NO

7

Count of allocated Unprofiled Demand Properties

Count of all properties in the Demand Area using the Unprofiled Demand category. If Pressure Managed Areas have been defined, the count of properties in each Pressure Managed Area will be reported also.

NO

10

Length of Mains

Length of mains is reported for the Demand Area. If Pressure Managed Areas have been defined Length of Mains is reported for each Pressure Managed Area also.

NO

10

Background Losses

Background Losses are calculated as:

where:

ICF = Infrastructure Correction Factor

PCF = Pressure Correction Factor

YES

10

Excess Unaccounted for Water

Excess Unaccounted for Water is calculated as:

Unaccounted for Water - Background Losses

YES

10

Equivalent Service Pipe Bursts at 1.6cum/hr - 50m AZNP

Equivalent Service Pipe Bursts are calculated as:

where:

Median Service Pipe Burst Flow Rate:

NO

10