Stormwater Sustainability - Home | MAV website

Stormwater

Sustainability

– a growing LGA challenge

Caroline CarvalhoCoordinator, Integrated Stormwater

Our City, Our Neighbors

Stormwater Sustainability – a growing LGA challenge

Yarra Ranges Council

Maroondah City Council

Whitehorse City Council

Monash City Council

Casey City Council

Greater Dandenong City Council

Blind

Creek

Monbulk

Creek

Ferny

Creek

Corhanwarrabul

Creek

Dandenong

Creek

Dobsons

Creek

Upper

Dandenong

Creek

Our City, Our Catchments

6 Major Waterway Catchments

49 Sub-Catchments

150,000+ Residents

50,000+ Ratable Properties

118 km2 Area

2/3 Boundary = Dandenong Ck

At Foothills of Dandenong Ranges

Rowville


Our City, Our Common Drivers

1

4

5

3

2

Plan Melbourne Activity Centres & Knox

Housing Strategy

1. Bayswater

2. Boronia

3. Ferntree Gully

4. Knox Central (Wantirna)

5. Rowville

• Planning & Environment Act

• Water Act

• Environment Protection Act

• National Construction Code & Building

Regulations

• Victorian Planning Provisions

• PP&WP Flood Mgt Strategy & Plans

• Stormwater Mgt Plans

• IWM Framework 2017


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4

5

3

2

1

4

5

3

2

Our City, Our Challenges

Correlation > Activity Centres & Flooding Hotspots

Correlation > Flooding Hotspots & Planning Development Pressure

Our Challenges – Development DemandsAreas of development demand = Areas of higher flood risk

Triggers for Change: Flood Events2004

2005

March 2010

Feb 2011

April 2012

Sept 2014

Dec 20167 big events in 14yrs

2016

20142014

2011

2016

2016

2014

10hrs later – local

pipes now start

coping

5hrs later – roads still

acting as flood storage

Emergency Services Access Issues

- Feb 2011 recognized as

biggest test to network

on record

- Melbourne’s SW network

designed to national

standards

- “no urban network

worldwide would have

coped”

- Highest rainfall @ 1-in-

500yr ARI – Foothills to

Rowville (The Age, Melb

Water, 2011)

Storm Event: 29th December 2016


Triggers for Change: Flood Events

• Past regulations failed to protect/secure natural overland flow paths – legacy issues

• Loss of creek floodplains = increasing loss of flood storage

• Easements too narrow and/or compromised over time

• Rainfall events becoming more intense (heavy summer storms/drier winters)

• Increasing population and urban densities = higher runoff volumes – the Victa mower is now obsolete

• Activity Centres / Housing Strategy = medium to higher density

• Less land available for mitigation solutions

“recent research by water reform experts identified more of Melbourne’s suburbs can come to expect flooding more frequently…networks will be overwhelmed almost twice as often by 2030, and the area affected by flooding may be 25% larger in extent”


Triggers for Change: Social Media


Triggers for Change: Social Media

‘Knox is now on notice to act reasonably and not recklessly in

relation to possible and reasonable, flood remedial works and

possible reallocation of resources to flood mitigation, so as to

ensure future (insurance) coverage.’ (2011)


Our Adaptations:

Rising to the challenge

a 20 year ‘blink’

2001 – Stormwater Quality Mgt Plan (SWMPs) & Signatory to Stormwater Agreement (MAV, EPA,

MelbWater)

1999 – New Urban Stormwater BPEM Guidelines (CSIRO/Melb Water)

1996 – Port Phillip Bay Environmental Study (CSIRO)

Warning…..wait for it………..

We all started with………

2019 – In Prep…New Stormwater Asset Management Plan > the SWAMP

2018-2020 – In Prep…New Integrated SW Mgt Guidelines for Development Industry

2017 – State IWM Framework released & creation of IWM Catchment Forums – shared ownership

2016 – CWP prioritisation criteria now requires fully integrated SW mgt infrastructure

2015-2020 – FMM & Condition Audits > 49 Sub-Catchments > Scheme Amendment (SBO2)

2015 – Knox Planning Scheme / LPPF / MSS Reviews – all now include IWM clauses/principles

2012 – Flood Management Strategy & Plans

2012 – R&D Investments and Partnerships - CRC for Water Sensitive Cities (9 years) & ARC Linkage Projects

2012 – Integrated Water Management Strategy & Water Balance for City of Knox

2012 – Directorate Restructure – New Integrated Stormwater Team (EFT x 6)

2010 – Drainage Asset Management Plan (now acknowledges WSUD infrastructure)

2010 – Knox Standard Drawings for WSUD Infrastructure – Series 190 for Developers

2010 – WSUD & Stormwater Management Strategy (3yr priority actions > informed CWP)

2010 – WSUD Policy & Procedures (Revised 2015)

2010 – New WSUD Project Engineer (EFT x1)

2008 – Sustainable Water Use Plan (2008-2015) – drought response

2006 – Stormwater Drainage Guidelines for Development industry

2005 – VPPs Clause 56.07-4 now part of Knox Planning Scheme

2002 – Knox’ first WSUD system constructed (VSAP grant funded)

2001 – Stormwater Quality Management Plan (SWMP) & Signatory to the Stormwater Agreement (MAV, EPA, MW)

1999 – New Urban Stormwater BPEM Guidelines (CSIRO/Melb Water)

1996 – Port Phillip Bay Environmental Study (CSIRO)

2019 – In prep – new Stormwater Asset Management Plan > the SWAMP > Capitalisation of IWM assets

2018-2022 – In prep – new Sub-Catchment Master Plans (x49)

2018-2020 – In Prep - new Integrated SW Mgt Guidelines for Development Industry

2017 – State IWM Framework released & creation of IWM Catchment Forums – shared ownership

2016 – CWP prioritisation criteria now requires fully integrated SW mgt infrastructure

2015-2020 – FMM & Condition Audits > 49 Sub-Catchments > Scheme Amendment (SBO2)

2015 – Knox Planning Scheme / LPPF / MSS Reviews – all now include IWM clauses/principles

2012 – Flood Management Strategy & Plans

2012 – R&D Investments/Partnerships - CRC for Water Sensitive Cities (9yrs) & ARC Linkage Projects

2012 – Integrated Water Management Strategy & Water Balance for City of Knox

2012 – Directorate Restructure – New Integrated Stormwater Team (EFT x 6)

Dedicated Resources = More rapid change

Knox’s IWM approach to stormwater integration…

to achieve adaptive and multi-functional assets that advance Knox’s

water security and resilience by collecting in times of surplus,

for use in times of shortage …

thereby adding long term value and improved liveability outcomes

for the region.

Our Team’s motivation

to create integrated water systems that locally

connect people to places where water meets


Retarding

Basin

Bask

etb

all

Sta

diu

m

Publi

c

Lib

rary

Shopping Precinct north & south of Boronia Rd

Remote

control car

club

Play Space

Pre

Sch

ool

After

BeforeWhen is an RB

not just an RB?


Wet Meadow Landscape

Treatment Wetland

Feature rock flow dissipater

Improved rock armoured inlets

Boardwalk & Seating Area

Amphitheatre – outdoor classroom

Sun-drenched Picnic lawns

Extensive connecting path network

Overflow weir & Spillway to Blind Creek

So when is an RB not just an RB?

When it’s an integrated stormwater solution designed to

be…

…a community valued piece of social infrastructure that:

Protects

Connects

Is Accessible

Creates Interest

Offers a Destination

Provides Social Inclusion

& Community Interaction

Enhances the Local Environment

Improves the standard of living and quality of life in the local

community…

and is still a functional stormwater asset.

Case Example: Flooding Complaints – Ferntree Gully

Case Example: take a catchment view – Look for Opportunities

A distributed approach – one size does not fit all

16% intensity factor applied to model runs to account for climate change…

If you opt for pipe upgrades to match material life of the asset…i.e. above best practice

Benefit?

...no discernible difference

to extents under Climate

Change Scenario Modelling

Use Technology – Talking Tanks

residential

precinct

industrial

precinct

The OneBox Unit:

• BoM interactive – pending storm (supply)

• Smart meter – ‘learns’ household usage behaviour (demand)

• Airspace in tanks maintained for flood storage

• Reduces localised flooding & pressure on pipe network

• Tanks remotely emptied before storm


Before IWM: Only 0.7% of total annual SW flow utilised effectively

After IWM:

312.6ML of annual flow being sourced = 98% reliability (non-potable)

Do

bso

n P

ark

, TN

A O

ffli

ne

94.1% 89.1%74.2% 73.4%

65.5%

5.9% 10.9%25.8% 26.6%

34.5%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1.5ML 1.15ML 600kL 575kL 450kL

Rel

iab

ility

Tank Sizes

PotableWater

Where there is a problem…step back…look for opportunities

4. Flood Mitigation

3. WQ Treatment

1. Site Irrigation x 2

2. Potable Conservation

Integrated Solutions > Dobson Park Oval & Tim

Neville Arboretum SWH System (IWM) Dobson Park/Arboretum site Topography

That was then….

This is now

Progressive Catchment Disconnections

Find and re-establish lost billabongs and wetlands to support and

revive our urban waterways and riparian zones…creating

community points of interest – desirable destinations

2 Ha

Juniper

WetlandYarrabing

WetlandCash Fues

Ephemeral

Wetland

Mint St Wetland

+ Manson Wetlands

+ Marie Wallace Wetlands

+ Colchester Wetlands

+ Suffern Wetlands

Partnerships = Advanced CWP Delivery

This is now… 18 mths on

Mint St Wetlands Suffern Wetlands

Colchester Wetlands

This is now… 18 mths on

Starlight WetlandsTN Arboretum Wetlands

What we have learnt….• Pit and Pipe upgrades – not the only way – take a bird’s eye view and see what the

catchment offers

• A package of solutions at various scales – in a ‘train’ – achieves adaptive SW mgt for flooding, potable substitution, waterway health & broader community benefits

• Don’t build for ‘best practice’ today – upgrade pipes for the material life of the asset –build in resilience now

• When you act – design for 50yrs from now – not for the reactive issue at hand

• Know your asset class – know your network – Condition Audits & Flood Modelling & Mapping aide in more accurate decision making

• Remember: One man’s trash is another man’s treasure – turn problems into benefits

• When you design – think broader – look for multi function / multi outcome infrastructure solutions

• Look for R&D opportunities – test the boundaries together – we don’t know what we don’t yet know

Finally, look for opportunities to: - Partner - Co-design- Collaborate- Share resources- Share knowledge- Undertake Research- Share project briefs & tools - Let’s save each other time & effort….

After all, we are in this together!

Thankyou for Listening

Email: [email protected]

mailto:[email protected]

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