SICK CITY STREAMS: NEW APPROACHES TO LEGAL TREATMENTS.

• Date: 01 December 2019
• Author: Nelson, Rebecca

I Introduction II Background and Framework for Investigation A Effects of Runoff from Urban Development on City Streams and Treating These Effects B A Novel Analytical Approach to Legal Responses to Stormwater Flows 1 Analysing Laws Using Concepts of Cumulative Environmental Effects: Developing Generalised Principles for a Legal Investigation 2 A Spatio-Legal Approach: Assessing a Complex Suite of Legal Controls Using Maps III Urban Realities and Legal Baselines and Goals for City Streams IV Legal Mechanisms for Protecting and Restoring City Streams from Stormwater Flows A Public Land Laws and Protected Areas B Land Use Planning Laws 1 Regional Mechanisms (a) Using the Urban Growth Boundary to Constrain Development (b) Public Zoning to Constrain Development and Build Stormwater Infrastructure (c) Using Precinct Structure Plans, Urban Renewal Plans and Distinctive Areas to Impose Stormwater Requirements on Development (d) Using Planning Overlays to Impose Stormwater Requirements (e) Using Local Stormwater Policies to Impose Stronger Stormwater Requirements 2 Project-Level Mechanisms (a) Statewide Considerations in Relation to Planning Permits (Victoria Planning Provisions) (b) Considerations That Apply to Planning Permit Applications for Subdivisions and Non-Residential Building Works: Amendment VC154 (c) Section 173 Agreements between Councils and Landowners C Building Laws D Environmental Laws 1 Regional-Level Mechanisms: State Environment Protection Policies and Special Area Plans 2 Project-Level Mechanisms: State Environment Protection Policies, Landowner Agreements and Conservation Covenants E Water Laws 1 Regional-Level Mechanisms: Declared Water Supply Protection Areas, Declared Floodways, and Drainage Services Schemes (Stormwater Offsets) 2 Project-Level Mechanisms: Liability for Unreasonable Flows and Easements V Spatial Application of Legal Mechanisms for Protecting and Restoring City Streams VI Reflections on Regulating Cumulative Environmental Effects and Recommendations A Melbourne's Stormwater Flow Controls from a CEE Perspective B Piloting Improved Stormwater Management for a Re-Imagined Yarra River 1 Values and Performance Objectives 2 Areas for Protection 3 Assessing and Evaluating Individual Projects and Proposals VII Conclusions I INTRODUCTION

Melbourne is the fastest-growing city in Australia, and one of the fastest-growing in the developed world. (1) Population growth occupies the front pages of newspapers and the work of government analysts. (2) Most focus on ensuring that growth is accompanied by adequate social infrastructure, particularly transport, (3) while relatively little popular attention has been devoted to the ways in which increasing development can degrade urban waterways. Yet vast new greenfield estates, large-scale urban renewal projects, and urban infill developments can, cumulatively, significantly affect city streams. (4)

Rivers and creeks form the arteries and veins of metropolitan areas--from large rivers like Melbourne's Yarra River (Birrarung) to half-forgotten drains alongside urban cycle paths. (5) They are sometimes 'the [most] significant natural areas remaining in urban landscapes'. (6) Urban waterways support important biodiversity, (7) provide physical and mental health benefits to city dwellers, (8) harbour important heritage and Indigenous and non-Indigenous culture, (9) and provide economic benefits through recreation, water supply, natural water treatment, and increased property values. (10) The cumulative impacts of development can threaten the capacity of city streams to provide these benefits.

Excess stormwater runoff, which is increased by development, is the 'fundamental driver' of most of the changes that degrade natural waterways in urbanising areas. (11) Future urban growth and more frequent extreme weather events triggered by climate change will likely increase stormwater and stream degradation. (12) City streams will become even sicker. Increased stormwater runoff is also expected to cause economic losses through increased flash flooding and significant new costs of upgrading drainage infrastructure. (13)

This phenomenon has attracted the recent attention of the Australian Senate (14) and state governments. (15) It lies within local governments' core legislative obligations to consider the cumulative effects of their decisions on the environment. (16) Nonetheless, no sustained scholarly work has analysed the full range of relevant current regulation in this area. Such an investigation is made particularly timely by the passage of the groundbreaking Yarra River Protection (Wilip-gin Birrarung murron) Act 2017 (Vic) ('Yarra Act'), which provides scope to implement new and more effective regulatory responses to the cumulative environmental effects of urban stormwater flows.

Using the case study of metropolitan Melbourne, this article explores the complex, layered laws that could and likely should be used to address the cumulative effects of increased stormwater on city streams. It demonstrates that a wider range of legal mechanisms could be used to address excess stormwater runoff than is commonly appreciated, though a brief traditional legal and qualitative analysis suggests important weaknesses in the range of existing legal mechanisms and the ways in which they are presently used. A quantitative spatio-legal analysis that uses maps to display and analyse law--the first time the approach has been used in a major Australian law journal (17)--reveals important gaps in the use of these mechanisms. These gaps leave waterways ecologically vulnerable and invite future economic losses from flooding. Its findings point to opportunities for new approaches using mechanisms under the Yarra Act to better link the longstanding silos (18) of land use and water management and address key weaknesses in current legal approaches. Its findings also speak to current efforts to reform stormwater-related laws in Victoria, (19) across Australia, (20) and internationally. (21)

More broadly, the study addresses a critical problem in environmental and natural resources law--the ways in which law can better address cumulative environmental effects ('CEEs'). CEEs are the significant aggregate effects of many actions, including spatially and temporally dispersed actions that may be individually minor. (22) CEEs range from climate change, (23) to biodiversity losses caused by clearing land, (24) to the biological accumulation of toxic pollutants. (25) Indeed, leading scientists have suggested 'planetary boundaries' that demonstrate a 'safe operating space' for aggregate human effects on the environment, beyond which there is a high risk of serious impacts on earth-system functions. (26) Around the world, legal responses to CEEs are considered grossly inadequate, requiring improvements in law, policy and associated guidance. (27) This case study brings a broad legal analysis into dialogue with the scientific literature on CEEs. Alongside the Melbourne case study, this dialogue produces generalised principles for examining legal mechanisms to address CEEs that share the particularly thorny characteristics of the environmental effects of urban development on waterways--namely, widespread and dispersed effects from numerous sources, a low threshold for significant environmental effects, and significant existing effects from historical activities.

Part II of this article sets out background information helpful for identifying, analysing and selecting legal mechanisms for protecting (preventing harm from runoff) and restoring (remediating existing harm from runoff) city streams, understood broadly as including major and minor waterways that appear 'natural', as well as highly modified watercourses such as open drainage channels. (28) First, it briefly outlines the scientific basis for development adversely affecting urban waterways. It then outlines how these effects can be characterised as CEEs, and summarises regulatory challenges related to addressing CEEs, leading to generalised principles for investigating relevant legal mechanisms. Finally, it outlines how spatial analysis can help, and briefly describes the spatio-legal methods pioneered in this article. Part III explores the broad concepts, values and goals that the law adopts for waterways, which take shape through legal definitions of waterways and processes for setting broad visions and detailed targets for them. These are the figurative legal destinations to which legal mechanisms to protect and restore the health of waterways advance. Part IV uses the lens of CEEs to examine these specific legal mechanisms relevant to the health of urban waterways in the context of stormwater flows. These mechanisms span a broad range of laws, here categorised for convenience into five areas: public (Crown) land law, including that related to protected areas; planning laws; building laws; environmental laws; and water laws. In relation to each area, the article first explores the current and potential future operation of relevant mechanisms doctrinally and qualitatively, by reference to specific instances of their use. Part V then examines, using a quantitative and spatial approach, the extent to which these mechanisms protect Melbourne's city streams, and the locations of 'hotspots' that are comparatively legally vulnerable to producing increased stormwater flows, and therefore adverse CEEs. Part VI concludes by summarising key opportunities for enhancing and extending the legal mechanisms reviewed to protect and restore sick city streams, both across metropolitan Melbourne in general and also in the context of the Yarra Act. Finally, Part VII concludes, reflecting on larger lessons for considering legal mechanisms to address CEEs.

II BACKGROUND AND FRAMEWORK FOR INVESTIGATION

A Effects of Runoff from Urban Development on City Streams and Treating These Effects

Compared to 'natural' streams, city streams have modified...