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FAO-PAP/RAC-MICOA

DEMONSTRATION ACTIVITIES - Xai-Xai IDP

7.1.5 Infrastructure Preliminary Projects Water Supply

There is no existing water supply to Praia Velha. The nearest existing pipelines are to the east in the existing town of Xai-Xai Beach but are old pipes of small diameter and uncertain condition designed to supply only the few existing houses. The pipes are connected to the small existing low level reservoir and are, therefore, subject to low working pressure and do not have capacity to supply Praia Velha.

The proposal is that the whole coast will be supplied from new high level reservoirs with a top water level of 88 metres which allows for development of stands to the 60 metre contour as a general rule. All new pipe work should be designed accordingly to a working head of 90 metres

  • -

    pipes should, therefore, be Class 9 in the PVC range of equivalent.

A new pipeline must, therefore, be laid to Praia Velha with Class 9 pipe. Initially, this pipe can be connected to the low level reservoir to supply water for the early development of the area. Provided the low level reservoir has water in it this elevation should be sufficient to supply the highest stands which reach the 45 metre level. It must be emphasised, however, that the reservoir is often empty, sometimes for a few days at a time so the supply at present is intermittent.

In due course Praia Velha can be connected to the new reservoir at higher pressure. Ideally, the pipes should be sized to supply the whole of the township of 120 stands but development can be phased to suit funding availability and projected growth rates for building of homes, although this will be more costly in the long run.

Proposed sizes and lengths of mains are given in Table 20 below:

Reservoir to east border of township

150

1100

Upper Ring

100

300

Central Arm

75

700

75

750

Lower Ring

100

400

75

600

Minor reticulation and interconnection

75

350

50

200

Total

4400

To Praia Velha

In Praia Velha

Diameter

Length

mm

In metres

Table 20

Praia Velha Water Supply and Reticulation

Location

The cost of the water supply system can be easily ascertained by applying current construction costs to the pipelines scheduled above and allowing for the cost of connections and water meters to each property. Policy will dictate as to whether an additional contribution is required from purchasers of stands towards the costs of the proposed new bulk water supply system with new pumps, pumping mains, reservoirs and chlorinating, and supply mains

Liquid Waste Treatment and Disposal

Initially, all liquid waste for the houses at Praia Velha will be disposed of by septic tanks with soakaways. Because of the steep terrain care must be taken in siting soakaways sufficiently within each property to ensure that there is no surface seepage onto lower neighbouring

properties or the road. sewerage reticulation with of the property.

All septic minimum

tanks should also be disruption in future and

located this will

to connect to the future usually be on the low side

135

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