Stormwater Strategic Management Plan by Wagga Wagga City Council

WAGGA WAGGA CITY COUNCIL DRAFT STORMWATER STRATEGIC MANAGEMENT PLAN FOR 2010

Executive Summary This Stormwater Strategic Management Plan is the framework strategic planning and implementation document for the overall management of stormwater in the urban areas of Wagga Wagga City Council. The plan is intended to form an integral part of the greater corporate business planning processes of Council, and integrates with the Community Strategic Plan 2008-18 and the Environmental Sustainability Strategy, 2009-13. The plan includes the detailed, catchment-specific stormwater management plans as originally completed in 2001, together with a range of recent and current plans and actions that relate to stormwater systems and services. Known major capital and operational projects including Wollundry Lagoon stormwater rehabilitation, installation of gross pollutant traps, inspection of underground pipelines, stormwater quality monitoring, and community consultation and education have been evaluated, provisionally costed, and prioritised within the plan. The plan has been prepared in parallel with a number of major study and modelling initiatives in stormwater, flood mitigation, and environmental management. The outcomes from these studies will not be available for consideration as part of the 2010-11 management planning process, though are expected to be key initiatives in subsequent plan reviews. The previous stormwater management plan failed to deliver key outcomes due to a lack of available funding. Council now has a viable funding option through an s496A annual charge on serviced properties that would raise funds specifically targeted for stormwater projects and service delivery. The option is capable of raising approximately $625,000 per annum, and is subject to limitations, justification, and disclosure. The plan must form an integral part of the Council corporate planning, management and budgeting system in order to comply with directives from the Department of Environment and Climate Change. The plan is to be reviewed, revised, and reported to Council annually as part of the annual corporate management budgeting and rating system. The strategy will enable a range of fundamental stormwater infrastructure benefits to be progressively implemented for the greater community including reducing the risk of localised flooding, improved storm water quality, reduction of some of the risks associated with open storm channels, culverts and pits with high velocity flows and depths of water. Council will need to continue to separately fund major capital projects as the annual sum raised by the fund will be insufficient to meet system-wide improvement and public

education programs as required by the guidelines as published by the Department of Local Government.

Table of Contents 1.0 2.0

3.0

4.0

5.0

6.0

7.0

8.0

Introduction……………………………………………………………………… 5 About this Strategic Plan………………………………………………………… 5 2.1 Objectives of the plan……………………………………………………. 5 2.2 Plan Structure……………………………………………………………. 5 2.3 Related Plans and Documents…………………………………………… 6 2.4 Definitions and Abbreviations………………………………………….... 7 2.5 Plan Integration…………………………………………………………... 7 The Current Stormwater Services Environment…………………………………. 9 3.1 The Operating Environment……………………………………………... 9 3.2 Catchment Values………………………………………………………. 10 3.3 Social Characteristics…………………………………………………... 10 3.4 Geology and Soils……………………………………………………… 10 3.5 Topography……………………………………………………………... 10 3.6 Climate………………………………………………………………….. 11 Known Stormwater and Flood Mitigation Issues………………………………. 11 4.1 Strengths………………………………………………………………... 11 4.2 Areas For Improvement………………………………………………… 12 4.3 External Environment…………………………………………………... 13 4.3.1 Opportunities…………………………………………………… 13 4.3.2 Issues of Concern……………………………………………….. 13 The Future of Stormwater and Flood Mitigation Services……………………... 14 5.1 Forward Strategic Direction…………………………………………….. 14 5.2 Strategic Objectives…………………………………………………….. 14 5.2.1 Stormwater and Flood Mitigation Operations………………….. 14 5.2.2 Condition Evaluation of Infrastructure…………………………. 14 5.2.3 Backlog Infrastructure Projects…………………………………. 15 5.2.4 Planning Strategies……………………………………………… 15 5.2.5 Environmental Monitoring……………………………………… 15 5.2.6 Finance………………………………………………………….. 15 5.2.7 Community Education………………………………………….. 15 Response Action Plan…………………………………………………………... 16 6.1 Priority 1 - Stormwater System Dynamic Hydraulic Modelling……….. 16 6.2 Priority 2 - CCTV Inspection of Underground Stormwater Pipelines….. 16 6.3 Priority 3 - Wollundry Lagoon Stormwater Upgrade…………………... 18 6.4 Priority 4 – Environmental Monitoring………………………………… 18 6.5 Priority 5 – Community Consultation & Education……………………. 19 6.6 Priority 6 – Pollutant Traps on Stormwater Systems…………………... 19 6.7 Future Improvement Initiatives………………………………………… 19 6.8 Implementation…………………………………………………………. 20 Section 496A Scheme…………………………………………………………... 21 7.1 Background……………………………………………………………... 21 7.2 Charging Structure……………………………………………………… 23 7.3 Annual Plan Review and Renewal Program……………………………. 23 Conclusion……………………………………………………………………… 24

1.0 Introduction This strategic plan is the framework strategic planning and implementation document for the overall management of stormwater in the urban areas of Wagga Wagga City Council. The plan is intended to form an integral part of the greater corporate business planning processes of Council, and integrates with the Community Strategic Plan 2008-18 and the Environmental Sustainability Strategy, 2009-13.

2.0 About This Strategic Plan 2.1

Objectives of the Plan

The primary objective of stormwater management is to facilitate the coordinated management of stormwater systems within catchments, and within the urban areas for which Council is responsible. Other objectives include the following: • • • • • • • • •

2.2

To improve the total environment and water quality of receiving waterways into which stormwater is discharged; To protect property and infrastructure against flooding by waterways; To reduce instances of local flooding by surcharging stormwater under storm event conditions; To improve stormwater and receiving water quality through erosion control, maintenance, bank stabilisation, and removal of introduced vegetation; To reduce risks to the general public associated with stormwater and related infrastructure; To evaluate stormwater as a potential water resource for recovery and reuse within the urban environment; To define roles and responsibilities of management and staff with respect to stormwater management and operation; To outreach to the greater community to ensure that an understanding and appreciation of the total stormwater environment will encourage community acceptance and ownership of the stormwater system; To integrate Council management initiatives within other regulatory authority regional management plans.

Plan Structure

This strategic plan is a continuation and development of catchment-specific stormwater management plans that were originally drafted and issued in November, 2001. The key development is to schedule all currently known issues within the urban stormwater system, quantify and prioritise them, provide a forward action and expenditure plan, and link the plan into corporate management system, the Community Strategic Plan, and the Environmental Sustainability Strategy for determination by Council as part of the 201011 delivery plan.

The 2001 stormwater management plan set consisted of eight volumes: • • •

Volume 1 was the primary management plan which provided an overview of the characteristics of the Wagga Wagga urban area and its individual stormwater catchments; Volumes 2 to 7 inclusive were catchment-specific plans, and; Volume 8 was a compilation of research and related documents that refer to or interface with the plan.

The catchment-specific management plans were prepared from available information, and represented a first phase in more detailed catchment-specific evaluation of the system. Each plan contained an evaluation of known operational issues and provided a prioritised action plan. It was anticipated at that time that very limited resources would be available to undertake any significant suite of actions. The prediction proved accurate. That situation has now changed as a consequence of the availability to Council of the option to implement an s496A scheme to raise funds to implement specific improvements for stormwater management and operation. These catchment-specific plans are being included within this plan with known amendments and additions to bring each catchment plan to a practical point of currency. The plans will be reviewed and revised in detail in forward years to ensure that no critical issues are overlooked for consideration or resolution.

2.3

Related Plans and Documents

A number of other management plans were completed in the intervening years, including the following: • • • • • •

The Community Strategic Plan, 2008-2018; The Environmental Sustainability Strategy, 2009-2013; The Wollundry Lagoon Water Quality Management Plan as prepared by AitkenRowe for the Environment Directorate in December, 2007, and in final format; The Plan of Management for Wollundry Lagoon as prepared by Planning for People and DSB, Landscape Architects, undated, but presumed to be 2008; The 2008-09 valuation of stormwater infrastructure in which a sample of the underground assets, and all surface assets of the stormwater system were condition rated and valued; Geotechnical evaluation of sections of the south bank flood levee system.

The current projects in stormwater services include a major overland flood flow study which is expected to be finalised by June, 2011. The study is being completed in parallel with but separate to this strategic plan.

The study will provide the system and site identification of critical overland flow situations, and will form an essential basis for a dynamic modelling study of underground pipeline assets and associated infrastructure.

The outcomes and critical recommendations of the study are not expected in time for consideration, prioritisation and inclusion in the 2010 business planning process as above.

2.4

Definitions and Abbreviations

The following definitions have been utilised in this plan: • • • • • • • • • • • • • • •

•

2.5

CSP: Community Strategic Plan; DLG: Department of Local Government; ESRS: Environment, Sustainability, & Regulatory Services; ESS: Environmental Sustainability Strategy; Stormwater: Any water flowing in waterways, and includes any groundwater that becomes surface water and any discharge from the Kooringal treatment works, Lake Albert and any other water storage system; GPT: Gross pollutant trap; SMP: Stormwater management plan; DECC: The Department of Environment and Climate Change; IP: Infrastructure Planning; MCMA: Murrumbidgee Catchment Management Authority; WWCC: Wagga Wagga City Council; PRS: Parks & Recreational Services; Waterway: Any natural river or stream, lagoon, naturally occurring wetland, and/or man-made open channel, wetland, or lake; WS: Waste Services; Urban catchment: A sub-catchment of the Murrumbidgee River that occupies land that has been substantially modified by urban development. Each catchment is a complete drainage system with a unique outfall to the river, usually through a billabong or natural creek system; WSUD: Water sensitive urban design.

Plan Integration

The DECC notice requires Council to prepare s496A plans that integrate into the Council’s management and strategic plans. The previous plan was integrated into the management plan system, but was limited in its achieved goals by minimal budget provision. This plan will form the basis of an s496A scheme for establishing a special rate to collect funds specifically for the development and improvement of the stormwater and flood mitigation system.

The s496A scheme needs to be fully justified in terms of projects or programs proposed to be undertaken and to be funded from the special rates scheme. This strategic plan provides the fully justified forward works program and basis for the s496A scheme.

3.0 The Current Stormwater Services Environment 3.1

The Operating Environment

The stormwater and flood mitigation environment for Wagga Wagga urban communities can be best summarised in the functional diagram as depicted below:

Government policies Stakeholders

Legislation

Councilâ&#x20AC;&#x2122;s corporate policies and objectives

Stormwater & Flood Mitigation Management

Regional obligations

Service Delivery

Customers

Some interrelationships are well defined while others such as stakeholder involvement and engagement are yet to be fully developed.

3.2

Catchment Values

The following are assumed to be the general catchment values and their associated priorities for both Council and the greater community: Ecological Values: • Maintenance and improvement of the aquatic ecosystem of waterways: • Establishment of aquatic flora in waterways: • Establishment of native trees, shrubs, and grasses in and near waterways: • Control of erosion: • Reduce the pollutant load from catchments: Social Values: • Improve visual amenity: • Reduce risks to human activities: Economic Values: • Reduce system maintenance costs: • Minimise risk of flooding to property: • Optimise infrastructure service life:

3.3

Medium High High High High High High Very High Very High Very High

Social Characteristics

The 2008 ABS Census highlight the following key points of the urban population: • • •

3.4

Wagga Wagga has a population of 61,656 (2008 Census); 19.5% of the population is between 5 and 17; 68.5% of the population is over the age of 18.

Geology and Soils

The Murrumbidgee River valley is an active depositional environment where extensive deposits of Quaternary alluvium overlie the older sedimentary rocks and granites. The alluvium includes gravels, sand, silt, and clays. This alluvium provides the strata for aquifers that contain valuable groundwater reserves. The Wagga Wagga Natural Resource Management Plan provides a summary table of the geology and of the soils of the Wagga Wagga area. Reference should be made to the Natural Resources Plan to comprehend the soils and their propensity to erode.

3.5

Topography

The Wagga Wagga urban area is substantially located on the floodplain of the Murrumbidgee River, with the topography of the river flats consisting of slopes of less than 10%.

The floodplain is subdivided by the Willans Hill range that rises up to 120 metres above the floodplain and runs from near Lake Albert to the south-west of the urban area. The range features steep slopes that range up to 20%. The topography of the Wagga urban stormwater catchment is subdivided as follows: Gradients 0–2

Area (Ha) 2270

% of catchment 38

2–5 5 – 10

Description Level to gently inclined Gently undulating Undulating

1990 994

33 17

10 – 20 20 - 33 33 – 50 >50%

Rolling Hilly Mountainous Precipitous

493 177 37 2

8 3 1 0

3.6

Climate

The climate of the Wagga area is described as “warm temperate, with hot, relatively dry summers and cold, relatively wet winters”. The dominant influence on the Wagga climate is that of pressure systems moving from west to east across the region. These pressure systems are sometimes associated with extreme daily temperature variations and thunderstorm activity. Recent research by the CSIRO and the Bureau of Meteorology predict climate change impacts in the form of reducing rainfall and more intense storm events for the Wagga Wagga greater urban area.

4.0

Known Stormwater and Flood Mitigation Issues

The current situation of the stormwater and flood mitigation systems is summarised as follows:

4.1

Strengths • •

•

The stormwater system generally copes with minor storm events and continuous rainfall at a rate less than a one in one year storm event; The existing flow retardation basins throughout the stormwater system and catchments provide some reduction and attenuation in peak storm flows and trunk storm flow rates of flow. The exception is Wollundry Lagoon where a high maintained water level limits storm flow storage capacity; The river flood levees provide a comprehensive if limited defence of the majority of the low-lying urban areas that would otherwise be subject to inundation;

• •

• • • •

4.2

A limited CCTV survey of stormwater pipes completed in early 2009 revealed underground stormwater assets in reasonable condition for the known service age of the assets; Significant catchment planning, identification of operational system issues and challenges, and development of draft catchment plans were undertaken in 2001, with much of the information only requiring minor revision and updating to achieve current catchment management documents; A system overland flood flow study is currently being completed by a specialist consulting firm, and is expected to be completed by June, 2011; Some stormwater and stream flow is diverted into Lake Albert to provide increased water volumes for recreational purposes; Council has reasonable asset management information on stormwater and flood mitigation assets; Community awareness and attitude surveys have revealed that the community generally has a positive attitude towards the stormwater open floodway and flow retardation system, though is concerned at the extent of visible gross pollutants.

Areas For Improvement • • • •

• • • • • • •

Many surface and underground elements of the stormwater system cannot cope with design storm events of five and more years; Under-capacity stormwater drains result in overland flow paths that impact on private property; The results and implications of the dynamic overland flood flow system modelling and analysis will not be known in time for inclusion in the 2010-11 business planning process; The existing operating level of the Wollundry Lagoon is currently resulting in back-flooding of an extensive area of the contributing stormwater system, resulting in reduced capacity and accelerated structural deterioration of road pavements and stormwater drains due to tree root ingress and siltation; The extent of sedimentation limits the available capacity of the lagoon system to store and make stormwater available for parkland irrigation reuse purposes; The Bolton Park flow retardation basin is poorly configured resulting in extensive gross pollution of the surrounding area after each storm event; Council’s stormwater assets, including its many pipes and open drains, present a range of risks to the general public, and in particular to children, with the key risk being high stream velocities and vortexes that can contribute to drowning deaths; Pollution reduction on stormwater system outlets is generally limited to crude gross object screens, with provision for retention of smaller gross pollutants and sediment limited to some sediment traps; Concepts of sensitive urban water design have limited value in upland catchments where groundwater surcharging could exacerbate urban salinisation; The integrity of some flood levees is unknown and potentially susceptible to breach failure under peak flood events; The flood levees have limited capacity to protect against flooding;

• • •

4.3

The 2009 CCTV survey of underground stormwater pipes was the first systematic inspection to have been conducted. Knowledge of the current structural and hydraulic condition of the system is very limited; Existing community consultation and education initiatives are very limited; The 2009/10 annual budget for stormwater operations and maintenance, is currently $762,057 is insufficient to fund the identified projects considered essential to ensure safe, sustainable operation of the stormwater and flood mitigation systems;

External Environment

4.3.1 Opportunities The following key initiatives have previously occurred or are currently progressing in parallel with the development of the stormwater management plan, and have and/or probably will influence the development and implementation of the SMP; • The WWCC Community Strategic Plan has a number of objectives and initiatives that either directly or indirectly impact on or relate to stormwater services; • The WWCC Environmental Sustainability Strategy has extensive numbers of objectives and initiatives that either directly or indirectly impact on or relate to stormwater services; • The Joint Integrated Water Cycle Management Evaluation Study may have implications for the quality of stormwater discharged to receiving waters.

•

The JIWCMES provides some information on predicted climate change implications, with increased storm intensity (rate of rainfall), duration, and frequency potentially causing greater stormwater system surcharging and property damage. The Global Water Smart City Plan will undertake projects that will form integral components of the stormwater management plan.

4.3.2 Issues of Concern • DECC has issued directives to all regional councils for the preparation of SMPs; • DECC may ultimately direct higher levels of surveillance on the quality and compliance performance of stormwater outfalls to receiving waters; • Ongoing climate change is forecast to increase in the intensity, duration, and seasonal variation of rainfall and storm events such that design criteria applied over the past 50+ years cannot provide adequate capacity to receive and safely transport.

5.0 The Future of Stormwater and Flood Mitigation Services 5.1

Forward Strategic Direction

Council’s objective, as articulated in the Management Plan 2008-2012, is to “contribute to a vibrant growing community by providing excellence in leadership, and delivery of ‘best value’ infrastructure and services, supporting quality living in an improving sustainable environment”. Council’s Community Strategic Plan 2008/2018 addresses key strategic goals in the areas of Social, Economic, Environment and Governance. Sustainability is a key tenet of Council’s corporate philosophy. Sustainability has been an objective that has not been a feature of stormwater and flood mitigation services until recent years when the backlog of maintenance tasks and a willingness to address deteriorated and sub-standard assets has again become a corporate business focus. The WWCC Environmental Sustainability Strategy, 2009 – 13, provides a formal framework and extensive suite of strategic directives in which the SMP must focus on and achieve defined goals.

5.2

Strategic Objectives

5.2.1 Stormwater and Flood Mitigation Operations The primary objective in stormwater and flood mitigation is to operate and maintain the system assets to achieve best hydraulic performance and optimal service life with minimal risk to the communities served. Council operations teams are fulfilling this primary objective with the available annual budget. These budgeted funds enable basic operational services to be maintained, but do not provide for extensive deferred maintenance activities to be undertaken. Addressing and funding the works and activities needed to achieve industry-standard stormwater services must be funded from additional rates as provided under the provisions of s496A of the Local Government Act.

5.2.2 Condition Evaluation of Infrastructure Council operates an extensive system of underground stormwater pipelines most of which are located adjacent to buildings or under public roads and reserves. The vast majority of these pipelines are constructed of interlocking jointed pipe that, if displaced by ground movement, will create voids between the top of pipe and the surface. Failure to monitor pipeline condition risks voids causing surface collapse and subsidence.

5.2.3 Backlog Infrastructure Projects Funding shortfalls over many years and a loss of strategic direction have generated or contributed to a list of major infrastructure projects requiring urgent implementation. Forward strategic planning requires that these projects be evaluated, prioritised and implemented with appropriate urgency.

5.2.4 Planning Strategies Forward planning for new and redeveloped urban developments is critical if the additional stormwater loading is to be connected to existing stormwater infrastructure. Initiatives such as sensitive urban water design (WSUD), collection and reuse of rainwater, peak storm flow attenuation methods, in-stream stormwater treatment, recovery and reuse are all considered to be of critical importance in the future development of the stormwater systems. WSUD must be carefully considered given the potential impact of surcharging up-gradient groundwater systems that may exacerbate down-slope salinisation.

5.2.5 Environmental Monitoring Stormwater systems are known to be capable of significant pollution if public education on the function and outfall of such systems is not sufficiently understood by the greater community. Environmental monitoring is essential for Council to fully monitor and document actual system environmental performance, compliance with mandated discharge standards, and subsequent impact on receiving waters.

5.2.6 Finance All strategic planning is of little importance and outcome if not adequately funded to ensure timely implementation and long-term sustainable operation. The availability of establishing an annual charge under Section 496A funding now provides Council with a means of establishing and maintaining such targeted funding. Recurrent operational funding will remain funded through the annual rate.

5.2.7 Community Education Stormwater and flood mitigation predominantly systems serve urban communities. Urban residents are often fully aware of the way in which stormwater systems are designed and operate, and may not comprehend the consequences of individual environmental discharges on the final system outfall to receiving waters.

Community education and consultation is an essential component of implementing the stormwater management plan, particularly given that additional funding will be essential if critical projects are to be fully funded and implemented.

6.0 Response Action Plan The following forward action plan constitutes the first defined suite of specific projects that are intended to address the known weaknesses and issues within the urban stormwater and flood mitigation system. The complete plan, including this action planning component, is expected to be reviewed annually or following the outcome of any significant parallel initiative such as the Global Smart Water Plan and/or the dynamic stormwater system modelling project. Each review and revision will most likely alter the priority of actions that the previous plan had identified, and further high priority projects are likely to be included in the forward planning process. The key components of the plan in order of priority of action are as follows:

6.1

Priority 1 - Stormwater System Dynamic Hydraulic Modelling The development of an overland flood model of the stormwater system is a current project. The model should highlight system under-capacity, provide an explanation for known overland flows, and enable system capacity upgrades to be prioritised and implemented for maximum value for expenditure. Funding for the Major Overland Flood Flow Study was budgeted in 2009/10. The study is expected to be completed by June, 2011. The study is expected to highlight the need for development of an equivalent dynamic modelling of the underground pipeline system. Funding is proposed to be $60,000 per annum, with the model being prioritised to key systems known to be subject to overloading. The key findings of the model development will progressively become available for inclusion in this plan.

6.2

Priority 2 - CCTV Inspection of Underground Stormwater Pipelines CCTV inspections of underground stormwater pipelines can be undertaken with two methods: o Council owns and operates a pole-mounted CCTV camera that enables a limited view of the stormwater pipelines from an access pit. This system is quick, safe, cost-effective, and provides sufficient vision to establish that a particular pipeline is either straight and visually clear of obstructions and 16

excessive pipeline deflections, or that it is obstructed with a range of objects and conditions that require further detailed, in-pipe visual evaluation and an appropriate maintenance/rehabilitation response. o Council owns and operates a CCTV camera mounted on a robot tractor carriage that enables detailed inspection of the internal walls of a stormwater pipeline as it travels between access pits. This system is safe, and provides excellent vision of internal walls and joints to establish the structural condition and potential residual service life of a particular pipeline. The system requires extensive deployment, a competent operational crew to operate the system, and is limited in the length of pipeline that can be inspected daily. The underground stormwater pipeline assets of the Wagga Wagga urban area were inspected by CCTV in a planned, sampled manner for the first time in 2008-09. The initial sample represented less than 1% of the total system. The condition evaluation program should now constitute and be maintained as a sustaining, annual survey. Pipeline pre-cleaning ensures that the actual structural condition of the pipeline can be viewed and evaluated. CCTV inspection of the internal surfaces of the stormwater pipelines enables the existing condition of the assets to be established using a national pipeline condition evaluating code. The CCTV system can assist operators detect serious structural defects such as collapsed upper pipe sections that may cause surface subsidence and cavity formation. The system enables operators to locate and eliminate capacity limitations due to gross blockages (tree roots, obstructions, etc), and sedimentation of the pipeline cross-section. The condition rating output will form the basis of future cyclic asset valuations. Funding for pipeline pre-cleaning and CCTV inspection in 2008-09 was limited to $100,000 given that the system had not previously been applied in a systematic manner. The results were very good in that those pipelines inspected were able to be condition rated, immediate rectification responses planned, and the service life of the pipelines estimated. It is proposed that $100,000 per annum be allocated to ongoing CCTV in-pipe inspections. The resulting condition ratings will support future valuation of stormwater assets, and the risk of system failures and possible pipeline collapses better managed and minimised.

6.3

Priority 3 - Wollundry Lagoon Stormwater Upgrade The Wollundry Lagoon currently receives untreated stormwater from the Turvey Park urban stormwater catchment of 539 hectares. Such discharges have progressively deposited sediment and gross pollutants into the lagoon sections, contributing to an estimated 65,000 cubic metres of sediment and debris that has accumulated predominantly into the western sections of the lagoon. Reconstruction modifications in recent years raised the water level in the lagoon to provide a heat sink for the Civic Centre air conditioning cooling coils. This increase in top water level partially filled many of the contributing stormwater pipelines. These partially filled pipelines are now structurally deteriorating, filling with sediment at an accelerated rate, and reducing the storm event capacity of the system. A proposed rehabilitation plan has been prepared to remove the sediment and transport it to acceptable disposal, lower the level of the western sections of the lagoon system to reinstate pipeline capacity and service life, reduce lagoon bank slope for safety, and install pollutant and sediment pre-treatment systems on the majority of contributing stormwater pipes to ensure that the lagoon environment and water volume is sustainable into the future. The plan addresses the primary functional objectives of Wollundry Lagoon, and ensures that the future stormwater functions associated with the lagoon do not adversely impact on the sustainable long-term future of the system. The Wollundry Lagoon stormwater plan is estimated as follows: o 2010-11: o 2011-12:

$1,200,000 $1,300,000

Many elements of this expenditure are costs incurred for reasons of visual public amenity, aesthetics, and functional heat sink for the civic centre air conditioning system, and as such, it is not appropriate to fund these works in entirety from the proposed levy.

6.4

Priority 4 â&#x20AC;&#x201C; Environmental Monitoring

Environmental performance is as critical as hydraulic capacity and performance. Limited environmental monitoring information is available on the various stormwater catchments. Environmental monitoring should be reviewed, and if justified, be expanded and upgraded to identify key environmental characteristics of each catchment outfall. The expanded information will enable in-catchment works and community education to be targeted.

The project is proposed to consist of an initial review of current environmental monitoring practices, establishment of any additional sampling and analysis programs and sites, then implementation. Initial expenditure is proposed at $50,000 in 2010-11, and $50,000 in 2011.

6.5

Priority 5 â&#x20AC;&#x201C; Community Consultation & Education

The plan, including its funding and implementation, must be communicated to the greater community through effective consultation. Once adopted, the plan should be promoted to all levels of the community through a structured community education program. The plan proposes a budgeted sum of $50,000 in 2010-11. The program would include community consultation, outreach services to schools, and printing and distribution of promotional documents on the levy scheme and its objectives.

6.6

Priority 6 â&#x20AC;&#x201C; Pollutant Traps on Stormwater Systems

The proposed environmental monitoring and the current system dynamic modelling will highlight system sites where the installation of pollutant traps is warranted. Key sites are expected to include Bolton Park, Wollundry Lagoon and contributing stormwater systems. The program is proposed to be spread over several years to enable critical sites to be identified, and adequate funding to be budgeted. The most critical pollutant traps for the rehabilitation of Wollundry Lagoon are included in that budget item for installation in the 2011-12 financial year.

6.7

Future Improvement Initiatives

There is a range of current and future initiatives that are or should be evaluated for inclusion in the plan. The current list of initiatives is as follows: Issue/Weakness

Proposed Action Project

Expenditure, 2010-11 dynamic Defer to 2011-12.

Capacity limitations Overland flows.

Complete system modelling project. Monitor and include dynamic model study.

in Underway budgeted separately. Wollundry Lagoon Install GPTs and sediment $195,000 traps & remove sediment from lagoon. Bolton Park gross Install GPT and minimise $100K. pollution & risks. installation risks once outcomes of dynamic modelling are available.

Expenditure 2011-12 $60,000 Underway budgeted separately $100,000

Gross pollution of Install suitable GPTs and system waterways. sediment traps on major open storm water drains. Install two GPTs per annum. Levees. Undertake detailed geotechnical study, identify critical levee sections, and rehabilitate. Inadequate Undertake annual CCTV knowledge of inspections of 5% of pre-1975 condition of pipe system until all older underground pipe underground pipe assets have system been surveyed and condition rated. Existing Plan and commence to community implement community consultation & consultation and education education limited. program. Plan as sustaining project. Risks in Undertake a due diligence stormwater system audit of all surface stormwater assets. Complete for action in 2011-12 year. Limited data on Undertake specialist study of water quality in the water quality in the key stormwater stormwater catchments, & catchments. redesign water quality monitoring program. Total, 2010-11:

$100K.

$100K

Geo-Technical Budgeted study underway separately budgeted separately $100K $100K ($50K cleaning) ($50K CCTV inspection)

$50K.

$50K

$30K

Unknown

$50K.

$Unknown

$625,000

625,000

This proposed sum is beyond the resources of both the general stormwater budget and the proposed s496A special rating scheme, and must therefore be prioritised to achieve a realistic expenditure program for 2010-11. Future financial allocation will be subject to the completion of the Overland Flow Modeling Study, which will allocate prioties for future works.

6.8

Implementation

The 2001 stormwater management plan openly acknowledged that there was, at that time, insufficient funding available to effectively implement the recommended actions intended to enhance the management of stormwater and flood mitigation. The implementation of this plan is based on the premise of Council adopting and implementing an s496A rating scheme specifically for the purposes of developing and enhancing the management of stormwater systems and services.

The proposal is that this plan and the proposed s496A special rate scheme would be considered as integral and parallel proposals.

7.0

Section 496A Scheme

A key element of this plan is to develop and implement a Section 496A annual charge scheme for the provision of stormwater management services.

7.1

Background

The prime objective of s496A is to provide an additional annual property charge to fund the provision of stormwater systems. S496A provides as follows: Section 496A Making and levying of annual charges for stormwater management services (1) A council may, in accordance with the regulations, make and levy an annual charge for the provision of stormwater management services for each parcel of ratable land for which the service is available. (2) Subsection (1) does not authorise or permit a council to make or levy an annual charge for the provision of stormwater management services for rateable land that is: (a) Owned by the Crown, and (b) Held under a lease for private purposes granted under the Housing Act 2001 or the Aboriginal Housing Act 1998. Note. Section 555 (1) (a) provides that land owned by the Crown is not rateable land unless it is held under a lease for a private purpose. The DLG guidelines on s496A stormwater management service charge schemes, page 30, provides as follows: â&#x20AC;&#x153;The income from the charge can be spent on both capital projects and recurrent expenditure relating to new/additional stormwater management services such as: â&#x20AC;˘ planning, construction and maintenance of drainage systems, including pipes, channels, retarding basins and waterways receiving urban stormwater;â&#x20AC;? This clause is critical as it provides for Council to: o Plan for the effective upgrading of stormwater services, including augmenting the existing system to ensure adequate system capacity for statistically valid storm events in intensely developed urban areas such as the commercial area; o Construct stormwater works to augment the existing system; o Maintain the existing system such that its available capacity is made available for coping with storm events.

Maintenance includes cleaning of pipelines and pits, inspection of the system by CCTV survey systems, and repair of assets such as to make the system safe and minimize the risk of storm flooding and under-roadway void collapse events. The maintenance work effort will dominate the expenditure for the first 3 – 5 years until all assets have been returned to acceptable service standards. Augmentation works could begin once system analysis enabled augmentation works to be defined, costed, and prioritized. “• planning, construction and maintenance of stormwater treatment measures, including gross pollutant traps and constructed wetlands;” Many stormwater system outfalls are currently crude, poor performing installations that do little to improve stormwater quality prior to discharge to receiving waters. Some systems, particularly those serving commercial and industrial areas may require prompt prioritized action to minimise environmental impacts. “• planning, construction and maintenance of stormwater harvesting and reuse projects;” Such schemes, while very commendable, are a low priority given that the majority of the system has yet to be returned to a viable operational state. “• planning and undertaking of community and industry stormwater pollution education campaigns;” There are a number of model public education programs regarding stormwater pollution available within the NSW and National local government sector. Some could be implemented for limited expenditure and provide immediate benefits in parallel with the construction of gross pollutant traps. “• inspection of commercial and industrial premises for stormwater pollution prevention;” Such surveillance, while very commendable, has a low priority prior to the majority of the system being returned to a viable state. “• cleaning up of stormwater pollution incidents (charge can fund a proportion); • water quality and aquatic ecosystem health monitoring of waterways, to assess the effectiveness of stormwater pollution controls (charge can fund a proportion); and • monitoring of flows in drains and creeks, to assess the effectiveness for flow management (flooding) controls (charge can fund a proportion)

• staff specifically appointed to provide the stormwater management service associated with the charge (e.g., temporary project staff).” Such evaluation and condition rating fulfils Council’s responsibility to exercise due diligence in managing its assets, and enables Council to proactively plan and budget for the repair, rehabilitation, and/or replacement of deteriorated stormwater pipeline and associated assets.

7.2

Charging Structure

The DLG Section 496A Guidelines define the properties that can be included, and those that must be excluded from a funding scheme. Stormwater charges will be applicable to all properties, with the following exceptions, which are exempt by the State Government from the charge: - Crown Land, - Council Owned Land, - Land held under lease for private purposes granted under the Housing Act 2001 or the Aboriginal Housing Act 1998, - Vacant Land, - Rural Residential land or Rural Business land, not located in a village, town or city, - Land belonging to a Charity or Public Benevolent Institution. The stormwater charge would be levied on a property basis as follow: • •

7.3

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Residential Standard Stormwater: Residential Medium/High Density Stormwater (Subject to a Maximum charge of $250.00): Business Stormwater:

•

Business Strata Stormwater:

$25.00 per lot $12.50 per unit $25.00 per 350 square metres of land area (max $250.00) $12.50 per unit

Annual Plan Review and Renewal Program

It is proposed that this plan be subjected to reviews of approved and funded initiatives in works and services to ensure timely and budgeted completion of initiatives within each financial year. Additionally, the plan is proposed for annual review and approval, with the outcomes report, redrafted plan, and recommendations being presented to a meeting of Council. Adopted proposals and the resulting financial plan for the funding of the forward initiatives would then form an integral component of the corporate business planning process from which the general stormwater budget and the funding required from the s496A special rates scheme can be adopted and implemented.

8.0 Conclusion The Stormwater Strategic Management Plan builds on all prior and parallel current initiatives to ensure that stormwater and flood mitigation services are delivered in a costeffective manner with sustainable environmental outcomes. This plan is the framework for future annual plan revision and renewal. It offers Council the financial mechanisms to fully implement the key strategies.