Dear Watercare Services Limited,

These questions apply principally to the installation of new water infrastructure.

* What is the average expected service life of installed water infrastructure (assuming normal use and maintenance of moving and serviceable parts)? e.g. Is it 30year, 50 years, 100 years?
* In areas of expected population growth where additional infrastructure or replacements with larger components are expected before the end of life of the infrastructure, what is your standard initial capacity planning period? e.g. is it 20years, 50 years?
* If the initial capacity provided and expected life before the infrastructure is at capacity varies with the expected rate of growth, what is the relationship? Do you have a standard minimum initial capacity provided where growth is uncertain?
* Whose population growth and projected population numbers do you rely on for capacity planning?
* Please provide any research or documents you have discussing the relationship between the costs of reticulation (or alternatives for clean water and waste water provision) and population density.
* Is there an accepted cutoff point of population density where the provision of water reticulation infrastructure becomes uneconomic versus the use of localised water (rainwater) supply and sewage disposal (using modern systems) - e..g. between “urban” and “rural” areas?
* Put another way, is there a value of population density where the provision of reticulated services becomes economic for domestic customers relative to their provision and maintenance of their own water and sewage disposal systems? [In general and complications aside -i.e. On average and other things being equal]
* New modern urban homes can be designed to minimise reticulated water supply requirements and provide efficient grey and black water management to reduce the capacity requirements for public water infrastructure. Is that yet economic -I.e are the reticulation savings greater or less than the higher domestic house construction costs?

Yours faithfully,

William Foster