ipwea sustainability in public works conference - august 2016

What works well with communities to keep

communities working well?

A Howe, S Pope, A Stewart, T Boyle & G GilesSustainability in Public Works Conference

24-26 August 2016

Presentation Overview

1. Background to adaptation planning in Lake Macquarie City

2. Flooding and inundation issues in our first adaptation planning area

3. Our approach to developing the plan

4. Key lessons learned

Key economic statistics

Residential buildings at risk of inundation

Source: Department of Climate Change, 2009

Aerial photo

Belmont

Swansea

Belmont South

Marks Point

Lake flooding at Marks Point

June 19491.25m AHD

Feb 19901.00m AHD

June 20071.05m AHD

1. How to manage and coordinate the progressive raising of land, roads, drains and other infrastructure?

2. How to finance the extra costs in renewing infrastructure and who should pay?

3. How to support new development without adding to the risk from the increasing hazard?

Key adaptation planning questions

Are the environmental

effects manageable?

Will it work to reduce the risk from

flooding and inundation?

Will it help maintain

community lifestyle?

Do the benefits

outweigh the costs?

Questions considered in context of four key criteria

Solutions developed through comprehensive community engagement

Asset Class Asset Category

Proposed Asset Life

(years)

Design Flood Recurrence

Interval

Rise in Sea Level

(metres)

Roads, Cycleways & Footpaths

Bridges

Stormwater Drainage

Civic Buildings & Amenities

Other Land Uses

Foreshore Protection

Design standards for future assets

Asset Class Asset Category Proposed Asset Life

Design Flood Recurrence Interval

Rise in Sea Level (m)

Roads, Cycleways & Footpaths

Major roads 50 1:100 0.40 Minor roads 50 1:10 0.40 Cycleways 40 1:10 0.32Footpaths 40 1:10 0.32

Bridges Steel & concrete 50 1:100 0.40 Timber 20 1:100 0.16

Stormwater Drainage

Natural watercourses - - - Vegetated channels 30 1:10 0.24Lined channels 50 1:10 0.40 Inlet pits & pipes 50 1:10 0.40 Kerb & guttering 50 1:10 0.40

Civic Buildings & Amenities

Community halls 50 1:100 + 0.5m 0.40 Schools 100 1:100 + 0.5m 0.90Sports club buildings 50 1:100 + 0.5m 0.40 Amenities blocks 30 1:20 0.24Boat ramps 30 1:20 0.24Minor structures - - -

Other Land Uses

Golf courses 50 1:20 0.40Marinas 50 1:100 0.40Special uses e.g. airport Case by case

Foreshore Protection

Seawalls, groynes & revetments 50 1:20 0.40

‘Soft’ and temporary protection 30 1:20 0.24

1. Building trusting relationships is critical

2. Boundaries need to be clear and well scoped

3. Flexible but firm planning process is required

4. Establish clear objectives and performance criteria

5. Collaboration doesn’t stop with the plan

6. Improved understanding and ownership of plans will aid implementation

Key lessons learned

Thank youahowe@lakemac.nsw.gov.au

www.lakemac.com.au

@swampologist

Alice Howe