Stormwater harvesting – standards, regulations and Industry practice

Presentation to Recycle Water 2013

30 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

Definitions

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

• • • •

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

Licensing

Harvest Source

Melbourne Water drain, waterway or waterbody Council drain for domestic use – single property Council drain for multi- residential or commercial use

Legislation

Section 51,

Water Act

Not applicable Not applicable 1989 Council wetland, lake or waterbody for other than domestic use (not supplied by roof runoff) Section 51,

Water Act

Private drain within private property Not applicable Roof Runoff Exempt from requirements 1989 licensing

Responsibility

Melbourne Water Council approval only Council approval only Melbourne Water Council approval required No licence required Council approval may be required. The harvesting of water from Melbourne Water’s drains and waterways requires a licence under Section 51 of the Water Act 1989 http://iourivwatersolutions.com.au/ BH: 03 9502 4229

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

Stormwater Harvesting Scheme Major Components

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

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

Need to set some definitions…

Volume diverted Volume collected Volume utilized

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

Guidelines for Stormwater Harvesting on Melbourne Water assets

Design, Construction & maintenance of diversion structures

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

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 .

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

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.

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

Base flows and self-cleansing velocities

For 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.

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

Design Examples

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

Design Examples

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

Current Industry Initiatives

(A) Independent verification scheme for stormwater treatment devices (B) Development of Storm Water Harvesting Guidelines – VIC

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

Overview

 Joint initiatives of Melbourne Water and IPWEA  Participation 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 http://iourivwatersolutions.com.au/ BH: 03 9502 4229

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

a REGULATIONS

Concept

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

•

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.

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

Development of Storm Water Harvesting Guidelines – VIC

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

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.

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

Concept

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

• • • • •

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

Questions

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