Water efficiency:

Enhancing water consumption and rainwater harvesting

Author: Kabelo Chabalala

Mechanical Engineer

National Department of Public Works and Infrastructure

Date: 13 August 2019

ABSTRACT

• Increasing scarcity of fresh water

• Population increase, Lack of rain water

• Imposing water restrictions

• The use of grey water

• What is water efficiency?

• Reduction of water wastage

OVERVIEW

• Problem statement

• Related work done by others

• Methods

• NDPW&I contribution towards water savings

• Summary

• Discussion (Q&A)

PROBLEM STATEMENT

RELATED WORK

• Western cape –Water restrictions

WHY CAN’T WE USE SEA WATER?

• Lack of facilities

• Requires a lot of energy through desalination process to

break bonds in salt water

• Thermal distillation – Boiling water vapour

• Membrane separation – Reverse osmosis

METHODS

• Grey water – Used for non-potable purposes

• Rain water harvesting

• Material selection

• Water metering

GREY WATER

SHOWERS, WHB, SINKS, ETC

IRRIGATIONTOILET

WATER TREATMENT

WATER STORAGE

TANK

MUNICIPAL WATER

DRAIN/ IRRIGATION

BOOSTER PUMP

WASTE WATER RECYCLING

RAIN WATER HARVESTING

BOOSTER PUMP

RAINFALL

MUNICIPAL WATER

GUTTER/COLLECTOR

COARSE FILTER

WATER STORAGE TANK OVERFLOW CHANNELLED

TO GARDEN/ SEWER

ROOF

WATER SUPPLY FILTRATION

PIPE MATERIAL SELECTION

37% water lost due to aged and leaking infrastructure

WATER PIPE LIFESPAN

WATER METERING

• Historical water use against population size

• Identify trends and extrapolate future water demands

• Data capturing

NDPW&I CONTRIBUTION

• Custodian of government buildings

• High water demand in public buildings

• NDPWI instrumental and significant in contributing towards

water savings

• Development of green building norms and standards

SUMMARY/TAKE-HOME POINTS

• Reduce water bills

• Reduce water demand

• Pipe material selection

• Water consumption monitoring

CONTACT DETAILS

Telephone number: 018 386 5262

Email address: Kabelo.Chabalala@dpw.gov.za