Introducing demand

00:04

When using info works.

00:05

WS pro it is important that you understand how

00:08

this software accounts for the demand on water networks

00:11

demand,

00:12

which can vary over time is the water that is

00:15

required by users at a given point within the network.

00:18

For example,

00:19

the water required by a housing development would be

00:22

different from that of a school or factory.

00:25

Water transfers can be considered a positive or negative demand on

00:29

the network depending on if the water is entering the network,

00:32

negative demand or leaving it positive demand.

00:37

In reality,

00:38

a network will also experience some degree of leakage which is any water

00:42

lost from a point in the network that cannot otherwise be accounted for.

00:47

This leakage can be represented in info works. WS pro

00:51

water companies tend to have three general categories of water

00:55

revenue,

00:56

non revenue

00:57

and other

00:60

revenue.

01:00

Water is defined as metered or un metered consumption that is paid for by the user,

01:06

non

01:07

revenue. Water nrw

01:09

can be unauthorized use or losses due to leakage or main breaks.

01:14

Other is defined as exceptional demand or transfers.

01:19

The general principles of allocating demand in a network can vary

01:23

but a typical process involves first identifying the

01:26

various types of customers in the network.

01:29

Then

01:30

the 24 hour flow profile or daily usage

01:33

pattern is used to determine how to allocate water

01:37

to do this. You must identify leakage using the minimum nightly flow.

01:42

With the assumption that the water leaving the system at this time

01:45

is being lost to leakage rather than consumed by a user.

01:50

Then you subtract any known legitimate use flows from

01:53

the remaining flow to find the domestic demand profile.

01:58

Demand almost always varies over the course of a day.

02:01

And you can model it in one of two ways

02:04

using demand categories or transfer nodes

02:08

leakage can be constant or vary over the day.

02:12

When modeling demand in info works. WS pro

02:15

the demand and leakage are only calculated from the notes.

02:19

The demand diagram window is used to edit demand categories.

02:24

A demand category defines a 24 hour demand profile which is to be applied

02:29

at the nodes for each type of user such as customer demand or leakage

02:35

demand categories allow for different demand patterns across a

02:38

day of the week or daily slash monthly.

02:40

Scaling factors.

02:43

The demand profile can also be updated from live data

02:47

demand profiles are considered to be either factored or direct

02:52

factor.

02:53

Demand is the most common demand type in which we know the volume of water

02:57

consumed over an average day but not how it is used over that 24 hours.

03:02

The volume may be known as total use per property or person per day

03:07

and is typically measured as a volume of water such as cubic meters.

03:12

It may also be known as the average flow rate such as liters per second.

03:17

Best practice is to generate a 24 hour profile and normalize it for an average of one.

03:23

The demand at any given time is the total daily use divided by

03:27

the simulation time step multiplied by the factor at the time step.

03:32

Direct demand is a bit simpler as this demand type is used for monitored customers.

03:37

Generally large consumers

03:39

factories would be one example,

03:42

the volume of water used over time is already known.

03:45

So you would just assign this demand type to a node.

03:49

Direct demand can be scaled if necessary

03:53

transfer nodes are used to model transfers of water into or out of a network.

03:58

Examples would include network transfers,

04:01

bleeds or the output of a treatment works.

04:06

However,

04:07

these cannot be used as the only source of water in a network as

04:11

a source of pressure input is necessary such as a reservoir or fixed head

04:17

transfer notes can also be used to represent large customers.

04:20

But this is not recommended if the direct demand category is available

04:26

info

04:26

works.

04:26

W S pro uniquely supports customer points which can represent individual

04:31

customer properties and allow for a more accurate demand allocation.

04:36

Customer points link to a pipe which in turn links to a node.

04:41

This allows for more complex modeling

04:43

adjustment of demands and finer scale analysis

04:47

demand can also be manually allocated to nodes similar to

04:51

how it is done in info water or EPA net.

Video transcript

00:04

When using info works.

00:05

WS pro it is important that you understand how

00:08

this software accounts for the demand on water networks

00:11

demand,

00:12

which can vary over time is the water that is

00:15

required by users at a given point within the network.

00:18

For example,

00:19

the water required by a housing development would be

00:22

different from that of a school or factory.

00:25

Water transfers can be considered a positive or negative demand on

00:29

the network depending on if the water is entering the network,

00:32

negative demand or leaving it positive demand.

00:37

In reality,

00:38

a network will also experience some degree of leakage which is any water

00:42

lost from a point in the network that cannot otherwise be accounted for.

00:47

This leakage can be represented in info works. WS pro

00:51

water companies tend to have three general categories of water

00:55

revenue,

00:56

non revenue

00:57

and other

00:60

revenue.

01:00

Water is defined as metered or un metered consumption that is paid for by the user,

01:06

non

01:07

revenue. Water nrw

01:09

can be unauthorized use or losses due to leakage or main breaks.

01:14

Other is defined as exceptional demand or transfers.

01:19

The general principles of allocating demand in a network can vary

01:23

but a typical process involves first identifying the

01:26

various types of customers in the network.

01:29

Then

01:30

the 24 hour flow profile or daily usage

01:33

pattern is used to determine how to allocate water

01:37

to do this. You must identify leakage using the minimum nightly flow.

01:42

With the assumption that the water leaving the system at this time

01:45

is being lost to leakage rather than consumed by a user.

01:50

Then you subtract any known legitimate use flows from

01:53

the remaining flow to find the domestic demand profile.

01:58

Demand almost always varies over the course of a day.

02:01

And you can model it in one of two ways

02:04

using demand categories or transfer nodes

02:08

leakage can be constant or vary over the day.

02:12

When modeling demand in info works. WS pro

02:15

the demand and leakage are only calculated from the notes.

02:19

The demand diagram window is used to edit demand categories.

02:24

A demand category defines a 24 hour demand profile which is to be applied

02:29

at the nodes for each type of user such as customer demand or leakage

02:35

demand categories allow for different demand patterns across a

02:38

day of the week or daily slash monthly.

02:40

Scaling factors.

02:43

The demand profile can also be updated from live data

02:47

demand profiles are considered to be either factored or direct

02:52

factor.

02:53

Demand is the most common demand type in which we know the volume of water

02:57

consumed over an average day but not how it is used over that 24 hours.

03:02

The volume may be known as total use per property or person per day

03:07

and is typically measured as a volume of water such as cubic meters.

03:12

It may also be known as the average flow rate such as liters per second.

03:17

Best practice is to generate a 24 hour profile and normalize it for an average of one.

03:23

The demand at any given time is the total daily use divided by

03:27

the simulation time step multiplied by the factor at the time step.

03:32

Direct demand is a bit simpler as this demand type is used for monitored customers.

03:37

Generally large consumers

03:39

factories would be one example,

03:42

the volume of water used over time is already known.

03:45

So you would just assign this demand type to a node.

03:49

Direct demand can be scaled if necessary

03:53

transfer nodes are used to model transfers of water into or out of a network.

03:58

Examples would include network transfers,

04:01

bleeds or the output of a treatment works.

04:06

However,

04:07

these cannot be used as the only source of water in a network as

04:11

a source of pressure input is necessary such as a reservoir or fixed head

04:17

transfer notes can also be used to represent large customers.

04:20

But this is not recommended if the direct demand category is available

04:26

info

04:26

works.

04:26

W S pro uniquely supports customer points which can represent individual

04:31

customer properties and allow for a more accurate demand allocation.

04:36

Customer points link to a pipe which in turn links to a node.

04:41

This allows for more complex modeling

04:43

adjustment of demands and finer scale analysis

04:47

demand can also be manually allocated to nodes similar to

04:51

how it is done in info water or EPA net.

Video quiz

Which of the following is NOT an example of revenue water consumption?

(Select one)
Select an answer

1/1 questions left unanswered

Step-by-step Guide

When using InfoWorks WS Pro, it is important to understand how this software accounts for the demand on water networks. Demand, which can vary over time, is the water that is required by users at a given point within the network.

Water transfers can be considered a positive or negative demand on the network, depending on if the water is entering the network (negative demand) or leaving it (positive demand).

In reality, a network will also experience some degree of leakage. This leakage can be represented in InfoWorks WS Pro.

A presentation slide containing details about water demand on water networks.

The general principles of allocating demand in a network can vary, but a typical process involves:

  1. Identify the various types of customers in the network.
  2. Use the 24-hour flow profile or daily usage pattern to determine how to allocate water.
  3. Identify leakage using the minimum nightly flow with the assumption that the water leaving the system at this time is being lost to leakage rather than consumed by a user.
  4. Subtract any known legitimate use flows from the remaining flow to find the domestic demand profile.

A presentation slide on allocating demand with a graph of a daily usage pattern.

Demand almost always varies over the course of a day, and can be modelled using demand categories or transfer nodes. Leakage can be constant or vary over the day.

A presentation slide with details on demand categories.

Factored demand is the most common demand type.

A presentation slide with details on factored demand and a sample graph.

Direct demand is used for monitored customers, generally large consumers. The volume of water used over time is already known, so this demand type is simply applied to a node. Direct demand can be scaled if necessary.

Transfer nodes are used to model transfers of water into or out of a network.

A presentation slide with details on transfer nodes.

InfoWorks WS Pro uniquely supports Customer Points.

A presentation slide with details on demand allocation.

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