stormwater harvesting – standards, regulations and industry practice presentation to recycle water...

Stormwater harvesting – standards, regulations and

Industry practice

Presentation to Recycle Water 201330 May 2013

http://iourivwatersolutions.com.au/ BH: 03 9502 4229

Overview Current status of stormwater harvesting in VIC Typical SWH project’s components & function Melbourne Water Guidelines for SWH diversion• Overview • Functional requirements• Base flow & maintenance flow requirements• Design examples

Joint initiatives of Melbourne Water and IPWEA• IVS – independent verification of stormwater

treatment devices• Stormwater Harvesting Guidelines

Questions http://iourivwatersolutions.com.au/ BH: 03 9502 4229

Definitionso Urban stormwater - “net increase in run off and

decrease in groundwater recharge resulting from the introduction of impervious surfaces such as roofs and roads within urban development”

o “Urban stormwater” is only available within the urban growth boundary

o Base flow in waterways is not considered urban stormwater - no access to base flow will be permitted


Interim allocation rules• If stormwater is flowing to the sea via a drain,

100% of the stormwater may be harvested

• If stormwater is flowing to a stream from an existing development up to 50% of existing stormwater can be harvested for use and 50% is reserved for the environment

• If there is a scheme to harvest more than 50% of the resource a study is required to assess implications for the environment

• All stormwater generated from new development is available for harvesting


Licensing

The harvesting of water from Melbourne Water’s drains and waterways requires a licence under Section 51 of the Water Act 1989


Harvest Source Legislation Responsibility Melbourne Water drain, waterway or waterbody

Section 51, Water Act 1989 Melbourne Water

Council drain for domestic use – single property

Not applicable Council approval only

Council drain for multi- residential or commercial use

Not applicable Council approval only

Council wetland, lake or waterbody for other than domestic use (not supplied by roof runoff)

Section 51, Water Act 1989 Melbourne Water Council approval required

Private drain within private property Not applicable No licence required Roof Runoff Exempt from licensing

requirements Council approval may be required.

Administration

Stormwater harvesting schemes continue to be managed through voluntary application of national and state guidelines

Relevant guidelines: Australian guidelines for water recycling: managing health and environmental risks (phase 2) - stormwater harvesting and reuse (NRMMC, EPHC et al. 2009)

No compliance monitoring requirements (voluntary compliance)


Stormwater Harvesting Scheme Major Components


Need to set some definitions…


Volume diverted

Volume collected

Volume utilized

Guidelines for Stormwater

Harvesting on Melbourne Water

assets

Design, Construction &

maintenance of diversion

structures http://iourivwatersolutions.com.au/ BH: 03 9502 4229

To assist stormwater harvesting proponents Melbourne Water has developed standard drawings and associated technical guidelines for the design, construction and maintenance of diversion structures for stormwater harvesting on Melbourne Water assets. The availability of these drawings and guidelines is expected to deliver the following benefits:

•To assist proponents and applicants in developing a suitable design likely to be supported by Melbourne Water•To ensure that Melbourne Water’s operational and environmental requirements are met and the outcome is therefore consistent with stormwater harvesting principles.



Functional requirements

• reliable diversion of designed flow rates and volumes and uniform diversion rate control

• min hydraulic impact on the existing drainage system

• automatic operation and reliable performance (e.g. no moving parts)

• minimal risk of blockage• minimum maintenance requirements• safe access for inspection, maintenance and

cleaning• allowance for flow calibration and metering• structural integrity • prescribed flow is being passed through

(environmental and/or self-cleansing flows)• ability to be isolated or shut off in case of

maintenance requirement or pollution incident.


Base flows and self-cleansing velocitiesFor all new diversion structures constructed on

Melbourne Water drainage assets, allowance should be made to pass low/base flows through the system both prior to and during times of flow diversion in order to avoid sediment deposition and associated maintenance problems in the drainage network.

The minimum self-cleansing velocities for the design of these flows must be calculated on a case by case basis using the boundary shear stress approach.

These calculations shall demonstrate that the design solution allows for the continuation of base flows through the system and that these flows produce the boundary bottom shear stress equal to or exceeding the pre-set minimal boundary bottom shear stress of τ ≥ 1.5 Pa.

Design Examples


(A) Independent verification

scheme for stormwater

treatment devices

(B) Development of Storm Water

Harvesting Guidelines – VIC http://iourivwatersolutions.com.au/ BH: 03 9502 4229

Current Industry Initiatives

Overview

Joint initiatives of Melbourne Water and IPWEAParticipation and support from Environmental

Protection Authority Victoria (EPA Vic), Victorian Department of Health (DOH VIC), Victorian Civil Contractors federation, Storm Water Victoria, CSIRO, Monash Uni and other industry representative


Independent verification scheme for stormwater

treatment devices http://iourivwatersolutions.com.au/ BH: 03 9502 4229

Project Objectives

The overall aim of this project is to establish the regulatory and administrative framework, product testing and validation protocols and performance database for the storm water treatment devices to enable the better utilization and broader uptake of Integrated Water Cycle Management (IWCM) in Victoria


Concept


a

REGULATIONS

ADMINISTRATION

TECHNICAL

Jurisdiction and extent•The proposed IVS is developed and implemented in the state of Victoria, Australia serving as a pilot for the broader National scheme.

Devices covered by the scheme•This Independent Verification scheme applies to pre-engineered, commercially-available technologies for storm water treatment.


Development of Storm Water Harvesting Guidelines – VIC


Project Objectives

• The objective of this project is to produce comprehensive guidelines for the practical implementation of storm water harvesting schemes in VIC as part of an Integrated Water Cycle Management (IWCM) approach.

• The resultant document has the potential to be included as an appendix to the new revision of Urban storm water best practice environmental management guidelines (BPEMG), adding consolidated knowledge from across Australia to the practical implementation of SWH schemes.


Concept


Conclusions• Stormwater harvesting schemes continue to be

managed through voluntary application of national and state guidelines with no regulatory compliance monitoring requirements

• Definitions and interpretations vary greatly across the industry

• No verification and/or validation requirements for performance

• Number of industry initiatives both at the state and National level

• Future directions


Questions


stormwater harvesting – standards, regulations and industry practice presentation to recycle water...

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