Nejeni Construction and Project Management (Pty) Ltd

Plumstead Retreat

Plumstead Retreat Pressure Management Project
Client City of Cape Town
Location Plumstead and Retreat, Western Cape
Scope Of Work Design, construction and commissioning of advanced pressure management solution for Plumstead and Retreat. The Project involved the construction of 2 PRV installations for Plumstead and 2 PRV installations for Retreat.
Schedule 2010/11

Project Detail

General Information

Statistical Information

Client contract number Contract Number: 222Q 2010/11
Project name: Plumstead Retreat Pressure Management Project
Project description: Design, construction and commissioning of advanced pressure management solution for Plumstead and Retreat.
The Project involved the construction of 2 PRV installations for Plumstead and 2 PRV installations for Retreat.
Client / Local authority: City of Cape Town
Main Contractor Brink and Heath Civils (Pty) Ltd
Technical design (Sub-Consultants to
Main Contractor)
Mechanical and Civil Works: UFP Consulting
Structural Works: De Villiers Sheard

 

Actual Installations

The contract involved the construction of pressure management installations at the following locations:

Plumstead Retreat

  • Stirling Road and Prince Georges Drive
  • Lourier Road and Prince Georges Drive

Retreat

  • Scottsville Road and Prince Georges Drive
  • Military Road NW and Prince Georges Drive

Supply Main and PRV Details

Zone PRV Location

Supply Main

PRV Size

Nominal

Material

OD

Tee (inlet)

Tee (outlet)

PRV supply

Current

Future

Plumstead Stirling

300

CI

345

200

200

200

200

200

Plumstead Lourier

300

AC

363

250

250

250

250

250

Retreat Scottsville

300

AC

363

250

250

250

250

250

Retreat Military (NW)

300

CI

345

300

250

250

200

250

 

Figure 6.1: Lourier Street PRV loggings between 08/06/12 and 22/06/12

Figure 6.3: Combined Plumstead flow from 08/06/12 to 22/06/12

Figure 6.5: Scottsville Street PRV logging from 18/06/12 to 02/07/12

Figure 6.6: Combined Retreat flow from 18/06/12 to 02/07/12

Table 6.1: Plumstead savings with pressure management

Lourier Street PRV

Sterling Street PRV

Fixed

Open

Fixed

Open

Upstream Pressure

PMAX

m

96.0

95.0

91.0

91.0

PMIN

m

82.0

80.0

77.0

76.0

P.Ave

m

90.0

89.3

85.6

85.4

Downstream Pressure

PMAX

m

67.0

94.0

49.0

87.0

PMIN

m

52.0

77.0

47.0

48.0

P.Ave

m

53.6

87.4

48.1

80.9

Critical Pressure

PMAX

m

66.0

98.0

36.0

74.0

PMIN

m

45.0

70.0

22.0

35.0

P.Ave

m

54.7

88.5

31.8

63.9

Zone

P.Ave

m

54.2

88.0

39.9

72.4

 

Fixed

Open

Combined Flow

QMAX

m3/h

408.0

492.0

QMIN

m3/h

24.0

84.0

Q.Ave

m3/h

210.6

249.5

Ave.MNF

m3/h

35.0

85.0

Savings

Reduction in MNF

m3/h

-50.0

Reduction in Ave. Flow

m3/h

-38.9

Water savings/d

m3/d

1200.0

saving/m pressure reduction

35.5

Water savings/annum

m3

438 000.0

Rand savings/d*

R

11 400.0

Rand savings/annum*

R

4 161 000.0

* Savings based on water price of R9.50 per Kl.

Table 6.2: Retreat savings with pressure management

Military

Scottsville

Fixed

Open

Fixed

Open

Upstream Pressure

PMAX

m

102.0

101.0

101.0

100.0

PMIN

m

68.0

72.0

85.0

80.0

P.Ave

m

84.9

85.3

93.3

90.6

Downstream Pressure

PMAX

m

65.0

98.5

45.0

98.0

PMIN

m

41.0

68.0

38.0

57.0

P.Ave

m

41.8

83.7

39.1

88.8

Critical Pressure

PMAX

m

62.0

118.0

48.0

96.0

PMIN

m

54.0

82.0

34.0

56.0

P.Ave

m

58.4

101.3

37.0

80.5

Zone

P.Ave

m

50.1

92.5

38.0

84.6

 

Fixed

Open

Combined Flow

QMAX

m3/h

360.0

480.0

QMIN

m3/h

12.0

96.0

Q.Ave

m3/h

171.6

257.9

Ave.MNF

m3/h

35.0

95.0

Savings

Reduction in MNF

m3/h

-60.0

Reduction in Ave. Flow

m3/h

-86.4

Water savings/d

m3/d

1 440.0

saving/m pressure reduction

34.0

Water savings/annum

m3

525 600

Rand savings/d*

R

13 680

Rand savings/annum*

R

4 993 200

* Savings based on water price of R9.50 per Kl.

Table 6.3: Summary of project savings

Zone

Unit

Plumstead

Retreat

Total

Water Saving/yr

m3

438 000

525 600

963 600

Financial saving/yr

R

4 161 000

4 993 200

9 154 200