Manila, PhilippinesITAPEVÍ Project, Brazil - Carried out by BBLMadhya Pradesh Region, Indore, India - Carried out by WRPSebokeng/Evaton Area, Emfuleni, South Africa - Carried out by WRPTrinidad & Tobago - Carried out by VeritecCity of Toronto, Canada - Carried out by VeritecEmfuleni Municipality, South Africa - Carried out by WRPKhayelitsha Township, Cape Town, South Africa - Carried out by WRPNew Providence, Bahamas - Carried out by Paul Fanner & Julian ThorntonZagreb, Croatia - Carried out by IMGDOrange River Basin, South Africa - Carried out by WRPDover Region, Norfolk County, Ontario, Canada - Carried out by VeritecRegional Municipality of York, Canada - Carried out by VeritecRustenburg Local Municipality, South Africa - Carried out by WRPCaledon Well Systems, Region of Peel, Canada - Carried out by VeritecSao Paulo, Brazil - Carried out by Julian ThorntonSaskatoon Saskatchewan, Canada - Carried out by VeritecToronto, Canada - Carried out by VeritecPeel, Ontario, Canada - Carried out by VeritecWestern Highveld, Mpumalanga, South Africa - Carried out by WRP
A detailed, validated, water balance was undertaken in Trinidad and Tobago in order to obtain a reliable assessment of the volume of Non-Revenue Water (NRW) in the islands, as a component of the development of a Water Master Plan for the country.
Trinidad: System input is 956 Mld based upon 107 water sources. The island has a population of 1.25 million of which only 16.6% have full service. FSE is 53.3% and 5% population is completely un-serviced.
Tobago: System Input is 46.1 Mld with 24 water sources. The island has a population of 56 thousand of which only 39.6% have full service. FSE is 63.3% and 15.2% of the population is un-serviced.
A pilot water loss reduction project was executed in order to develop a detailed validated water loss assessment in an unmeasured system, together with a water efficiency survey for the WASA master plan.
Assessing Unmeasured Residential Consumption
The most significant problem with undertaking this water balance was that only 1.5% of residential customers are currently metered. There has never been any reliable assessment made of unmeasured residential consumption volumes in Trinidad and Tobago, so the volume of use was by far the greatest uncertainty in the water balance. Intermittent Supply: Only 17% of customers receive a 24/7 water supply. It was therefore necessary to develop a methodology to address these problems and develop a reliable assessment of this use component. Meters were installed on a randomly selected sample of unmeasured residential customers from across all of Trinidad and Tobago.
Water Efficiency Surveys
In order to assess the scope of water efficiency savings within residential properties in Trinidad and Tobago, a water efficiency survey was undertaken which included a telephone survey of 425 randomly-selected, unmeasured residential customers. It was designed to collect basic information on usage of fittings and appliances within these properties. In addition an internal water use survey was carried out in 270 customer properties.
Validating System Input Volume
There are more than 100 sources supplying the system in Trinidad and Tobago. It would be impractical to test all of them. For this reason, the key system input meters, accounting for 75% of production, were subject to field tests.