Integrated Solution Enhances Livability of West Melbourne

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MS4 Program Prepare for change

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Sustainable Strategy GSI measures

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Water Harvesting Beyond rain barrels

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Watershed Management Satellite remote sensing

Volume 8 / Issue 2 Summer 2020

The Official Publication of the WEF Stormwater Institute

MANAGEMENT

Greening the Pipeline transforms urban space

Published by Water Environment Federation 601 Wythe Street, Alexandria VA 22314-1994, USA www.wef.org

Summer 2020 Volume 8 Issue 2

Contents

Executive Director WEF Walter Marlowe, P.E., CAE Stormwater Institute Director Adriana Caldarelli acaldarelli@wef.org Publisher Nic Christy nchristy@wef.org Editor-in-Chief Pamela Wolfe pwolfe@wef.org

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Associate Editors Justin Jacques, Will Fowler Subscription Information Water Environment Federation Tel: +1 (301) 604-3305 csc@wef.org

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Global Advertising Representative Suzanne Shutty sshutty@wef.org

Other information Subscription rates <HDU 8. DQG 5HVW RI WKH :RUOG 86 Š WEF – 2020 No part of this publication may be reproduced by any means without prior written permission IURP WKH SXEOLVKHUV (YHU\ HĆŹRUW LV PDGH WR ensure the accuracy of material published in World Water: Stormwater Management. However, WEF will not be liable for any inaccuracies. The views expressed by contributors are not necessarily those of the editor or publisher. The title World Water: Stormwater Management is registered at Stationers’ Hall. The magazine is printed on environmentally friendly paper. Both text paper and cover stock are elementary chlorine free and sourced from paper suppliers with a well planned environmental policy. The magazine includes editorial photographs provided and paid for by suppliers. World Water: Stormwater Management. is published quarterly by WEF and distributed in the USA by Mail Right International, 1637 Stelton Road B4, Piscataway, NJ 08854. Periodicals Postage Paid at Piscataway. POSTMASTER: Send address changes to Stormwater, WEF Publishing C/o 1637 Stelton Road, B-4, Piscataway NJ 08854 ISSN 2053-1362

32 Regulars 7 32 33

Stormwater Report News Solutions Events

Seth Brown Executive Director, National Municipal Stormwater Alliance Dan Fajman (StormTrap) Chair of Marketing Committee, Stormwater Equipment Manufacturers Association

Features 6 12 14

Design and Repro www.j-graphicdesign.co.uk Printed by Buxton Press Ltd %X[WRQ 'HUE\VKLUH 8.

Editorial Advisory Board

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Brian Currier Senior Research Engineer 6DFUDPHQWR 6WDWH 2ĆąFH RI Water Programs

Perspectives

The MS4 Program at a crossroads

Infrastructure Planning Green Infrastructure

Kimberly Grove &KLHI 2ĆąFH RI &RPSOLDQFH DQG Laboratories, Department of Public Works, City of Baltimore

Water Harvesting

Chris Kloss National Green Infrastructure Coordinator, US Environmental Protection Agency

Coronavirus and stormwater: A challenging mix Bioretention key to natural sustainable stormwater strategy in San JosĂŠ Looking beyond garden rain barrels to stormwater management

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Integrated Water Management

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Flood Management

Leigh Padgitt &HUWLĆŽHG 3URIHVVLRQDO LQ 0XQLFLSDO Stormwater Management

Integrated solution enhances livability of West Melbourne

Submersible pump design for challenging VWRUPZDWHU UXQRĆŹ

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James Lenhart, PE, D.WRE &KLHI 7HFKQRORJ\ 2ĆąFHU &RQWHFK Engineered Solutions

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6DWHOOLWH UHPRWH VHQVLQJ IRU HĆŹHFWLYH ZDWHUVKHG management

Leslie Schehl Supervising Engineer, Watershed Operations, Metropolitan Sewer District of Greater Cincinnati Jim Schlaman Director of Water Resources, Black & Veatch Neal Shapiro Secretary, American Rainwater Catchment Systems Association Srini Vallabhaneni 6PDUW 6HZHU 2ĆąFHU .DQVDV City Water

Cover image Aerial view of Williams Landing Park, Australia. Photo by Melbourne Water

World Water: Stormwater Management Summer 2020 5

Integrated Water Management

A partnership approach in Melbourne, Australia, repurposes a heritage-listed asset to enhance community wellbeing. David Howard of GHD and Nino Polon of Melbourne Water explain how integrated water management solutions – involving stormwater collection and reuse – can enhance urban life. A pilot project in Melbourne demonstrated WKH SDUWQHUVKLSŞV HƹFDF\ LQ UHGXFLQJ VWRUPZDWHU ưRZV improving stormwater quality, and reducing potable water UHTXLUHPHQWV ZKLOH DOVR RƏHULQJ OHVVRQV WR KHOS ZLWK WKH full implementation of the pilot.

Integrated solution enhances livability of West Melbourne I

nspired by New York City’s Highline Park in New York, United States (US), the Greening the Pipeline initiative in Melbourne, Australia, is an ambitious project that will transform the city’s 27-kilometer (km), decommissioned, heritage-listed main outfall sewer (MOS) corridor of linear reserve into parkland. The project plans to accomplish this while also using a sustainable water supply sourced from stormwater to green the reserve. To kickstart Greening the Pipeline, a 100-meter (m) linear pilot park was commissioned in the Melbourne suburb RI :LOOLDPV /DQGLQJ Ĺœ WR VKRZFDVH WKH effective tranformation of the open sewer into a sustainable community open space with an integrated stormwater management system. The pilot park project harvests, treats, and reuses stormwater from a nearby catchment on a 100-m-long section of the MOS, next to the 23-km Federation Bike Trail. The volume of stormwater harvested from the pilot is estimated to offset the equivalent of 1.5 million liters per year (ml/yr) in potable water, with the broader 27 km offering significant scope to increase the amount of locally sourced stormwater and recycled water used along the corridor. The pilot project explores the costs and benefits associated with upscaling the pilot and greening the entire 27-km linear reserve. A partnership comprised of Melbourne Water, Wyndham City Council, VicRoads, and City West Water, is heading the initiative. Further support is provided by Greening

the West, a 23-organization partnership of councils, government agencies, and industry and community groups committed to greening Melbourne’s Western Growth Corridor. The Victorian State Government Department of Environment, Land, Water and Planning provided funding to Melbourne Water for the pilot project. Melbourne is the capital of the state of Victoria, located in Southeast Australia with a population of approximately five million residents. Melbourne Water is responsible for providing reliable water supply, sewerage, drainage, flood management, and healthy waterways for the area. The city of Wyndham is in Melbourne’s Western Growth corridor. The municipality has below average rainfall, high-heat vulnerability, and the community have one of the lowest per-capita open-space percentages LQ 0HOERXUQH Ĺœ SDUWLDOO\ DV D UHVXOW RI ODUJH parcels of land, which are yet to be developed. A key open-space asset in Melbourne’s Western Growth Corridor is the Federation Bike Trail, which largely runs along the MOS reserve. As part of Greening the Pipeline, there is great opportunity to enhance the Federation Bike Trail as a key active recreation and commuting trail for West Melbourne residents whose communities are still predominantly reliant on vehicles for travel. The MOS was an engineering marvel when constructed in the 1890s in response to sewage and waste that were traditionally

18 World Water: Stormwater Management Summer 2020

transported via open street channels and eventually discharged untreated into Port Philip Bay and waterways nearby. As a result, cholera, diphtheria, and typhoid ran rife. The MOS solved this sanitation problem by taking sewage away to a nearby treatment plant in the suburb of Werribee via a network of underground and open sewers and a pumping station at another suburb, Brooklyn. The MOS is state heritage-listed because of its important role in Melbourne’s transition from “Smellbourne,� because of the odor issues, into a modern metropolis. The MOS was decommissioned in 1993 and replaced by the Western Trunk Sewer, which transported sewage underground. As residential growth has begun to approach the MOS, the asset has effectively become a physical divide between the communities that neighbor the linear reserve. There is now an opportunity to repurpose the MOS from a 19th century asset for use in the 21st century. Livability through Greening the Pipeline Melbourne Water has a mission to enhance the life and livability of all Melburnians. Their aim is to strengthen the wellbeing of communities, co-create the world’s most desirable places to live, and enhance the natural environment. One of the ways Melbourne Water is enhancing life and livability is by exploring opportunities that activate its many landholdings and assets, such as the Main Outfall Sewer, in partnership with public and private organizations.

Integrated Water Management

INTEGRATING THE REQUIREMENTS OF A SAFE AND FUNCTIONAL OPEN SPACE WITH THOSE OF A STORMWATER QUALITY TREATMENT SYSTEM IN A HERITAGELISTED ENVIRONMENT IS NOT UNCOMMON. HOWEVER, IT CAN BE CHALLENGING.

Urban greenspaces support multiple functions

Above: The pilot park project harvests stormwater from a nearby catchment located next to the 23-km Federation Bike Trail. Top: A 100-meter linear pilot park in the Melbourne suburb of Williams Landing harvests, treats, and UHXVHV VWRUPZDWHU SURYLGLQJ PXOWLSOH EHQHĆŽWV WR the community. Photos by GHD

Melbourne Water engaged the global engineering consultancy GHD, based in Australia, to develop a detailed design for the pilot park, which was based on stakeholder feedback in 2013 and community consultation in April 2016. Completed in April 2017, the pilot park has provided many benefits to the community and the environment. For example, compared to 2016, the number of park visitors increased 48 percent in 2019. And, thermal mapping of the pilot park indicated there is significant urban cooling as a result of the green landscape interventions. Other environmental benefits include improved flood mitigation,

Urban communities and environments depend on urban greenspaces for different services including recreation, aesthetic, cultural, climate resilience, and environmental and ecosystem functions. However, many cities around the world are experiencing rapid population growth and land-use changes. Urbanization, however, is reducing available green lands and negatively affecting biodiversity, hydrological function, active and passive recreation opportunities, and amenity values of this transformed landscape – which has a material impact on communities’ liveability and residents’ physical and mental wellbeing. To reduce the adverse effects of the loss or lack of greenspace in urban environments, government agencies in Australia are actively pursuing the implementation of multifunctional green infrastructure projects in both the public and private realm. In particular, water utilities are playing a significant role in implementing such initiatives since they are often a major landholder in urban areas. Even though their core responsibility is the provision of water and sewage services, there is a growing trend for water utilities to support livability and environmental sustainability. Many water utilities are evolving to implement water-sensitive urban designs, naturebased solutions, multi-functional green spaces, as well as providing ecosystem services, which are now within their remit.

World Water: Stormwater Management Summer 2020 19

Integrated Water Management

The pilot project integrates multiple features such as an outdoor exercise station located near rain JDUGHQV ZKLFK ĆŽOWHU VWRUPZDWHU WKURXJK SK\VLFDO FKHPLFDO DQG ELRORJLFDO SURFHVVHV WR UHPRYH sediment and pollutants to improve water quality. Photo by GHD

water quality, reduced stormwater flows into waterways by 1.5 ml/yr, and a reduction in total suspended solids, phosphorous, nitrogen, and gross pollutants from treated stormwater. The Greening the Pipeline pilot project demonstrated the sustainability and costeffectiveness of harvesting, treating, and reusing stormwater to irrigate the green space. Pilot results also offer insights on the broader benefits that should be considered, including: impacts to river health and Port Philip Bay by treating stormwater along the corridor, the ability to offset developer stormwater nutrient contributions (which could create a potential source of funding), the cost and availability of sourcing stormwater (such as local catchment draining to the relevant precinct), and the cost and availability of sourcing recycled water for the broader community. The Greening the Pipeline initiative and associated pilot-park offer a number of lessons that would be helpful in upscaling the pilot and greening the rest of the 27-km linear reserve. Some key findings include: • The important role the community can play in the codesign process • How a heritage listed asset can be repurposed to benefit the community • How alternative governance and financing models can contribute to a shared value outcome • A repeatable, open-space solution that is cost effective, safe, and practical to maintain • How to address high-heat vulnerability through the creation of a linear park and sustainable irrigation • How livability can be underpinned by an integrated water management solution. Integrating the requirements of a safe and functional open space with those of a stormwater quality treatment system

in a heritage-listed environment is not uncommon. However, it can be challenging. The key considerations for achieving an innovative and practical outcome within the heritage-listed MOS included: • Maintaining the vista down the axis of the MOS • Minimizing disturbance to the MOS by minimizing the number of conduit penetrations of the structure • Enhancing the structural integrity of the MOS • Providing a practical solution for treating and storing stormwater for reuse • Providing effective signage to educate the community about the MOS and its new function. In the Greening the Pipeline pilot park, the design of the stormwater treatment, storage, and reuse system balanced these considerations. Therefore, it was able to use the MOS to store water without compromising the structural integrity of the structure or create a public safety hazard, minimize excavation costs by using the airspace within the MOS, minimize pumping costs through the use of a gravity feed from the underground drainage network into the primary storage as well as from the bioretention treatment cells into the reuse tanks, and provide an activated and safe space on top of the MOS to connect the communities on either side that were previously disconnected by the physical barriers along the reserve. A shared value outcome A multiagency partnership comprised of Melbourne Water, Wyndham City Council, City West Water, and VicRoads are leading the planning and delivery of the Greening the Pipeline initiative. This approach has been driven by the nature of the MOS reserve given

20 World Water: Stormwater Management Summer 2020

the complex land ownership arrangements across the 40-m-wide corridor and a common goal to transform this asset for the benefit of the communities in West Melbourne. Melbourne Water is the waterway and drainage authority and the owner of the MOS asset where the linear park is proposed. The majority of the linear park is located within Wyndham City Council’s municipality, which is experiencing substantial urban growth. VicRoads is the state road authority responsible for the management of the MOS reserve, including the Federation Bike Trail that runs along the length of the reserve. City West Water is the local retail water authority with an interest in regional and local scale stormwater and recycled water initiatives. In addition to this, the project is further supported by the Greening the West initiative, which is a 23-organization strong partnership of councils, government agencies, industry, and community groups committed to advocating and delivering outcomes to green Melbourne's western region. A single agency or group cannot deliver a project of this scale in an efficient and cost-effective manner. Currently, shared value projects of this nature are typically funded from a combination of local, state, and Commonwealth taxes and utility bills. Melbourne Water is also exploring opportunities for private partnerships. Repeatable, open-space solution that is cost-effective and practical to maintain During the design of the pilot park, GHD identified key design principles to consider for future repurposing of broader sections of the corridor. The design process also aimed to develop solutions that could be replicated to form a consistent theme of typologies and materials that are cost-effective and safe, not leaving a long-term high-maintenance legacy for the asset owner. The design acknowledged the needs of the community, focused on achieving positive livability outcomes, and responded to the challenging nature of the local environment. Specifically, the design solutions considered connecting communities previously divided by the long and continuous fenced off MOS reserve by creating a permeable open space

Integrated Water Management

that also managed conflict between park users and bicycle movements along the highly used, high-speed commuter trail. The design also considered the need to combat high-heat vulnerability through shade structures and use of large canopy trees with year-long irrigation, while managing stormwater to improve water quality and provide irrigation through harvesting and passive irrigation. Also important was designing an environment to combat the low annual rainfall and compacted basaltic soils in order to establish trees and vegetation through species selection, tree pit design, and irrigation. The use of locally sourced materials, solarpowered lighting for main pedestrian routes, and the creation of habitat corridors, were also considered, among other design options. Address high-heat vulnerability In 2009, the Department of Human Services in Melbourne reported 374 more deaths in the city’s population than were expected during a heat wave. The greatest number of these excess deaths occurred in the western and northern suburbs of Melbourne and correlated with an absence of trees and greenspace. The Wyndham municipality is highly vulnerable to the risks associated with urban heat island, coupled with one of the lowest rates of open-space allocations in Melbourne. The Greening the Pipeline initiative, therefore, presented an opportunity to reduce the local urban heat island effects through the provision of more green open spaces. The Greening the Pipeline pilot park provided 54 established trees and approximately 1,200 square meters of irrigated landscaping (with a mix of turf and shrubs), which act to transpire and cool the surrounding climate through an irrigation network that uses locally sourced stormwater and potable back-up. In the summer of 2019, Melbourne Water used drone technology to capture a series of thermal images of the pilot park and an adjacent nonactivated comparison site, which revealed an ambient temperature that ranged between 40-44 degrees Celsius (104-111 degrees Farenheit). The results of the thermal capture showed a significant difference of approximately 20 degrees Celsius (68 degrees Farenheit) between the irrigated grass areas with trees, compared with the asphalt and concrete floodway. At this site, the cooling effect from irrigation of green space is significant. By creating a broader 27 km of linear parkland, the multiagency partnership proposes to transform the existing MOS reserve from an inaccessible space with very little vegetation into an accessible space with trees and vegetation that thrive, transpire, and cool the surrounding climate. This would be supported by an irrigation network that uses locally sourced stormwater or recycled water that will green the area all year round. Integrated water management solution sustains liveability Integrated water management (IWM) plays an integral role in facilitating more livable communities through water sensitive urban design principles and the provision of alternative water supplies – to support

A SINGLE AGENCY OR GROUP CANNOT DELIVER A PROJECT OF THIS SCALE IN AN EFFICIENT AND COSTEFFECTIVE MANNER.

of water to the tree root zone (such as stormwater and class A recycled water) • Irrigate the mid-root zone of the tree root ball by using subsurface irrigation where possible.

Community willing to pay for increased amenity The Cooperative Research Centre for Water Sensitive Cites established a 2019 Investment Framework for Economics of Water Sensitive cities (INFFEWS) value database, which provides a repository of nonmarket values relevant to water sensitive systems and practices but is currently lacking specific green infrastructure for the mitigation of information on large-scale livability projects. urban heat island effects and provision of A subsequent 2019 case study, “Assessment areas for residents to connect, play, and of non-market benefits of implementing largerelax. The Greening the Pipeline pilot scale WSUD: Greening the Pipeline," identified park exemplifies the role stormwater can significant nonmarket benefits associated play in greening an arid environment. with options to restore the MOS reserve, both Traditional approaches to streetscape design in terms of the potential to reflect increases typically create low-water environments and in house value and in terms of residents’ increase high-heat vulnerability in summer. willingness to pay for improvements in amenity. Consequently, trees and landscaping often The study found that completed upgrades cannot survive when root zones are cramped on a nearby section of MOS reserve increased or compromised, particularly in areas of low the value of residential properties within average rainfall and adverse soil conditions. 50 m of the MOS Reserve by 5.3 percent. In Therefore, the green infrastructure trend – addition, the study found that 86 percent of including the use of trees and vegetation in the the populated of 624 residents were willing streetscape – often works to retain as much to pay for improvements in the reserve. Most ZDWHU DV SRVVLEOH LQ WKH ODQGVFDSH .H\ IHDWXUHV respondents were willing to pay for all of of this new approach include using stormwater the different MOS improvements such as runoff for watering, considering streetscapes trees, maintained grass areas, seats, drink as a valuable component of the stormwater fountains, and toilets. There is a growing runoff treatment train to protect urban evidence-base for public investment in waterways, and appropriate use of reticulated water-sensitive urban designs, nature-based recycled water for streetscape watering. solutions, multi-functional green spaces, Green spaces create more livable suburbs, as well as providing ecosystem services. improve community health, and provide The Greening the Pipeline pilot park is an a cleaner environment. Street trees not example of a transformation project that has only provide the shade and beauty that repurposed a 100-year plus decommissioned are vital to our quality of life, they reduce heritage asset to suit the immediate and longurban heat island effect, filter air, store term needs of the local community. Led by stormwater, and sequester carbon. Melbourne Water and designed by GHD, the The western suburbs of Melbourne have pilot park has enhanced the area’s livability lower average rainfalls than east of the city, so by connecting communities and providing the Greening the Pipeline initiative includes for a safe and sustainable open space where ways to increase greenery from a planning and the green space is secured all-year round design perspective with the following actions: by recycled stormwater. In partnership with • Plant more trees and plant the right trees Wyndham City Council, City West Water, for the prevailing site conditions VicRoads and Greening the West, the • Encourage the planting of trees on private Greening the Pipeline will aim to replicate the land as well as within the road reserve principles of the pilot park across the entire • Adopt a “trees come first” principle when 27-km length of the MOS so that Melbourne’s considering the urban streetscape form west has an iconic linear parkland. • Select big trees with large canopies to create shade where possible Authors’ Note • Ensure a diversity of tree species and ages GHD Water Strategy Team Leader David to maximize resilience Howard and Melbourne Water Senior Livability • Increase the quality and volume of soil for Planner Nino Polon are based in Melbourne, trees, including improving the soil physiology Victoria, Australia. This article is based on within the tree root zone while ensuring “Greening the Pipeline – Re-purposing a backfill around tree pits is not compacted heritage-listed asset to enhance community • Increase the uptake of permeable pavements well-being,” a presentation included in the Water together with structural soils and proprietary Environment Federation Stormwater Digital soil cells to increase usable soil volumes Conference (www.wef.org). This online course around tree root zones features videos from presentations scheduled • Passively irrigate trees wherever possible by for the National Stormwater Symposium, grading road, footpath, and carpark runoff which were cancelled in early March. into tree pits For a complete listing of references, please • Consider larger scale IWM initiatives that send an email to: David.Howard@ghd.com provide development-wide alternative sources For more information, visit www.wef.org. World Water: Stormwater Management Summer 2020 21

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Integrated solution enhances livability of West Melbourne

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