Report 7 - Executive Summary
Guidelines for the Beneficial Re-use of Stormwater
This manual was developed to provide guidelines for the beneficial reuse of
stormwater at both an individual household and community level. The main sources
of stormwater considered are either from roof water or stormwater ponds. The
reuse of stormwater - directly from streams or from aquifer recharge - are only
briefly mentioned. Both potable and non-potable end uses are addressed. The
manual is divided into two sections:
- Guidelines for Individual Households (or small businesses); and
- Guidelines for Communities
The primary reason for this division is because the 1995 New Zealand drinking
water standards differentiate between supply of water to less than 25 people
(the individual household case) and the supply of water to more than 25 people
for more than 60 days in the year (the community case). Public liability issues
(and the need for maintenance requirements and performance testing) between
stormwater reuse by the individual household for ones own use and the supply of
water to a community are covered in this report.
Each section (individual and community) has been divided up into the
following sections:
- Introduction
- Water quality
- Hydrological Design
- Collection and Storage Devices
- Water Treatment
- Distribution
For information, a final section lists some examples of existing stormwater
reuse projects.
Individual householders, engineers, designers, planners, developers and
Councils who deal with stormwater will find this manual useful. By working
through each section of the manual the reader will be able to get an idea of the
likely water quality of the stormwater source to be reused, size the
collection/storage device based on the possible supply and demand quantities and
determine the likely type of treatment system required to meet the desired end
use water quality (potable or a selection of non-potable grades).
The manual recommends that before final designing of a reuse system, that
stormwater samples be tested over a period of time for actual quality and that a
cost/benefit analysis be carried out to determine the feasibility of such a
project. Notes are also given on the distribution, maintenance and likely
performance testing required to ensure that health standards are met.
This manual is the first edition commissioned specifically for Waitakere
City, but the principles would apply to all areas in New Zealand. It is the
intention that after review of this document, an update manual will be produced
for general use throughout New Zealand. The general manual for widespread use
will need to address specific environmental issues in different area (e.g.
quality of stormwater) differing rainfall patterns, availability of different
systems and different local regulations.
Report 7 - Full Version
Guidelines for the Beneficial Re-use of Stormwater
For a copy of this report or any further information please
contact us.
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