ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT

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1 Rules/criteria C38 Trees C38 is not applicable to this proposal as The Tree Protection Act 2005 does not apply as the ECD site is located outside the urban area declared by the Minister under the Act; The installation and construction of the enlarged dam will require existing trees and riparian vegetation, to be removed as required/where practicable; The proposed construction of the main dam, two saddle dams and associated works, including quarries, batch plants, storage, site office, containment areas, sediment basins and other amenities will have direct impacts on native vegetation as detailed in the ECD EIS; Any clearing required for site preparation and construction works will be undertaken in accordance with the requirements set out in the approved CEMP (the draft report is included with this submission); ACTEW has provided a commitment in the completed EIS to undertake offset works at a ratio of 2:1 for native vegetation and 1:1 for former pine forests/exotics areas that are impacted upon by construction and operational activities; and ACTEW will provide funding and resources to undertake offset works in the form of vegetation rehabilitation/other offset works that may be negotiated with the Territory. The areas and scope of this work will be negotiated with the Territory and any works that require DA assessment will form the basis of a separate DA as described in the ECD masterplan. C39 Bushfire risk mitigation Consideration against the Bushfire Risk Mitigation General Code is included at section 7.3 of this document. The risk of bushfires on the ECD was specifically considered in section 5.12 (pages ) of the completed EIS and identified the subject site to be located within a bushfire prone area. The proposal would not increase bushfire risk when compared to the existing Cotter Dam, as the ECD will comprise a bulk concrete structure (dam) and reservoir (water) which are both non-flammable/bushfire resistant materials; The Bushfire Risk Mitigation General Code requires that a bushfire risk assessment including recommendations be lodged with any Development Applications for Class 1, 2 and 3 (see Appendix A of the Planning for Bushfire Mitigation General Code). The ECD proposal is not a class 1, 2 or 3 building and therefore it does not require this assessment being completed; The ECD proposal complies with the requirements of the Planning for Bushfire Risk Mitigation General Code (see section 7.3 of this report for further details); and ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 27

2 Rules/criteria Construction activities carry an inherent risk of starting a fire that could spread off-site. The proponent acknowledges this risk and has prepared a draft Bushfire Management Plan to manage the risk of starting a bushfire. This plan will be considered approved as part of the CEMP that will be used to manage the day by day construction activities during construction of the proposal. Element 7: Site servicing C40 Waste management C41 Servicing and site management C42 Utilities C43 Septic tanks The ECD EIS included an assessment of the likely waste generation associated with the construction of the ECD project and the waste management strategies to be adopted to manage and mitigate the impacts thereof (refer to section 5.2.3, pages of the ECD EIS for details); ACTEW will adopt best practice management measures as detailed in the Development Control Code for Best Practice Waste Management in the ACT throughout the construction phase of the ECD project. Where possible ACTEW will promote recycling and beneficial re-use of waste materials; Waste Management will be conducted under a waste management plan that will be embedded into the approved CEMP for the project (see the Draft Waste Avoidance and Resource Recovery Management Plan included with this submission); and Also included in this DA is the TaMS Waste Management Plan pro-forma that has been completed with the waste information that applies to this proposal. This information should be considered in the context of the Draft Waste Avoidance and Resource Recovery Management Plan provided. The ECD can be readily serviced from the existing infrastructure in the vicinity. ACTEW will comply with any agency direction imposed. A Waste Management Plan is included with this submission. The applicant is a utility provider responsible for the provision of water, waste water and electricity services. These services (primarily electricity) will be provided to the site as required; and Telecommunications will be primarily through radio communications. Establishment of an optic data network is still being investigated and will form the basis of a separate DA. Not relevant to this proposal. 28 WATER SECURITY MAJOR PROJECTS JULY 2009

3 7 Other Territory Plan codes The following general codes apply to the ECD proposal and must be considered in determining this Development Application. The consideration of these codes is referenced in the Non-Urban Zones Development Code requirements (primary development code for this proposal) as detailed below (in brackets): Parking and Vehicular Access (Element 4 Criterion 26); Type 5 signs a single 1m construction information sign, displaying details of the site office location, will be located on the intersection between Paddy s River Road and Cotter Dam Road; and Type 6 signs a single 1m construction information sign, displaying details of the site office location, will be located on Settlement Road. All signage relates directly to the construction activities associated with the construction of the ECD. The design response to the relevant construction sign requirements is set out in table below (only relevant criteria are assessed). Signs (Element 5 Criterion 28 and 29); Planning for Bushfire Risk Mitigation (Element 6 Criterion 39); and Water Use and Catchment (Element 6 Criterion 33). 7.1 Parking and vehicular access The Parking and Access Code specifies vehicular access and parking arrangements for development in the ACT. The parking provision rate for major utility installations and outdoor recreational developments in the river corridor and mountain and bushland zones are subject to individual assessment. A detailed traffic impact assessment has been presented in Appendix U and section 5.1 (pages ), in the completed EIS (included with this submission) and mitigation measures were proposed to manage the likely impacts. Due to the temporary increase in traffic movements expected as part of construction activities a number of mitigation measures are proposed with regard to materials deliveries, truck movement, workforce movements and the like. These measures will be incorporated into a Traffic Management Plan that will be prepared and included in the CEMP that is being prepared in parallel to this proposal. In the context of permanent/post construction parking requirements the ECD is not expected to require more than a small number of parking spaces for incidental maintenance visitors (see C26 in section of this report). It is considered that the proposal will allow adequate parking within the secured site area to accommodate the future parking requirements of the proposal. 7.2 Signs The Signs General Code (March 2008) applies to the design, content and positioning of signs in the ACT. The intent of the code is to ensure that signs are a type appropriate to the Territory Plan land use zone. The proposed enlargement of the Cotter Dam requires a number of temporary construction signs to be erected to guide all construction staff safely throughout the construction area. No temporary signs will be illuminated and all signs will be removed once the dam has been commissioned. All signs have been designed to meet the requirements of the Signs General Code. The signage proposed includes the following four types and are detailed on drawings GHD-ECD-DAM- GN-SKT-1021 and GHD-ECD-DAM-GN-SKT Type 1 signs construction fence signage (0.5m x 0.5m) displaying no entry, are located intermitted along the length of the perimeter fencing of the site; Type 2, 2A and 2B signs two 1.5m construction information sign, displaying traffic delay information and site office location, displayed at locked gate on the Settlement Road intersection; Type 3 signs two 1m gate entry signs (information signs) displaying gate entry and safety information will be located at the locked gates off Brindabella Road and Kiosk Road; Type 4 signs two 1.5m construction information sign, displaying no site construction access, will be located at the entrance to Cotter Dam Road; Table 7.2 Signs General Code Rules/criteria Element 1: Use R1 Permissible signs R2 Content of design R3 Licensing Element 2: Built form C4 General built form criteria (This criterion is considered applicable to the full signage typology proposed for temporary construction signage proposed for the ECD project) R22 Construction site fence sign Rule met. The proposed signs are acceptable in the other zone identified in Table 1 of the Signs General Code. The proposed temporary construction information and fences signs relate directly to the construction of the ECD on the site. All signs will be removed upon demobilisation of the construction works. Rule 2 is met. All signs are principal construction signage and will be located at ground floor. A license to occupy unleased Territory land will be applied for to obtain access to the site during the construction of the ECD. Conditions relating to the signage proposed can be made part of this agreement. The proposed signage typology for the ECD proposal are temporary signs and in keeping with the proposed construction activities proposed. The proposed temporary signs meet the requirements of Criterion 4. Details of the proposed signage and their locations are illustrated in drawings GHD-ECD-DAM-GN-SKT-1021 and GHD-ECD-DAM-GN- SKT The proposed signage as detailed in section 7.2 of this report are to be constructed away from public roads and will not be illuminated. Given these considerations and the actual typology proposed it is considered unlikely that the proposed temporary signage will create a hazard to traffic or pedestrians or would create a hazard or nuisance in terms of lighting, glare or reflective or obstructions or distractions to road users. The signs proposed are temporary in nature and will be removed upon demobilisation of the construction works. Details of the proposed signage and their locations are illustrated in signage drawings GHD-ECD-DAM-GN-SKT-1021 and GHD-ECD-DAM- GN-SKT All construction site fence signs will be erected for the duration of the construction of the dam and will not be illuminated. The proposed construction site fence signage has a surface area of 0.5m x 0.5m and therefore meets this requirement. ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 29

4 Rules/criteria R 23 Illumination of construction site fence sign R59 Information sign surface area R60 Information sign height R61 Illumination: not illuminated R62 Setback Rule met signage proposed will not be illuminated. A general statement against Criterion C4 is provided above. This is applicable to all the proposed temporary signs. This rule is met. See drawing GHD-ECD-DAM-GN-SKT Rule met signage proposed will not be illuminated. Rule met. The proposed signage is to be constructed away from public roads. 7.3 Planning for bushfire risk mitigation The subject site is identified as being within a bushfire prone area within the code. The code (in Appendix A of the Planning for Bushfire Mitigation General Code) requires that a bushfire risk assessment and its recommendations be lodged with a DA for Class 1, 2 and 3 buildings (i.e. new buildings, extensions and alterations creating new Class 1, 2 and 3 areas). This development is not a Class 1, 2 or 3 buildings and therefore does not require this assessment and recommendation to be completed. The proposal, when compared with the existing Cotter Dam, will not increase the bushfire risk in the Lower Cotter Catchment, as it comprises a bulk concrete structure (dam and saddle dams) filled with water (Reservoir) and would not be constructed of flammable material (refer to section (pages ) of the completed EIS for further details). This proposal complies with the requirements of the Planning for Bushfire Risk Mitigation General Code. Element 3: Sign construction R132 Traffic safety This rule is met; refer to drawings GHD-ECD-DAM-GN-SKT-1021 and GHD-ECD-DAM-GN-SKT R133/134 Installation fixings This rule is met; refer to drawings GHD-ECD-DAM-GN-SKT-1021 and GHD-ECD-DAM-GN-SKT R135 Animated or flashing signs Element 4: Environment R136 National capital plan No animated or flashing signage proposed. The proposed signs are temporary in nature and are not prohibited under the NCP requirements for the site. Refer to section 4.6 of the EIS for an assessment of the NCP requirements in relation to the ECD project. Refer to Rule C21 of the Non Urban Development Code assessment above. Notwithstanding this, a draft Bushfire Management Plan has been prepared as part of the Construction Environmental Management Plan (CEMP) to cover the whole site. This draft management plan is included within this submission to enable the assessment of the DA. Refer to Rule C39 of the Non Urban Development Code assessment above and section (pages ) of the completed EIS for more detail. 7.4 Water use and catchment The purpose of Water Use and Catchment General Code is to identify waters of the ACT in terms of their permitted use and environmental values, and to identify the water quality and streamflow criteria related to the full protection of these uses and values. Overall, this proposal is consistent with the objectives of the Water Use and Catchment Code. Waters of the ACT and their catchments have been classified into the three water use catchment categories listed below: Conservation; R137 Heritage R138 Trees R139 Environmental control Heritage impacts in relation to the ECD proposal are being addressed under a Conservation Management Plan (CMP) approved by the Heritage Council under the Heritage Act Refer to Rule C32 of the Non Urban Development Code assessment above. Not relevant to this proposal as the Tree Protection Act 2005 does not apply to this area. Refer to Rule C38 of the Non Urban Development Code assessment above. This rule is met; refer to drawings GHD-ECD-DAM-GN-SKT-1021 and GHD-ECD-DAM-GN-SKT Water supply; and Drainage and open space. The classification of the catchment relates to the predominant water use or environmental value within that catchment. An assessment of the proposal s performance against the objectives and policies relating to each water catchment classification included in the code is provided below Part A: conservation catchments The Water Use and Catchment General Code (March 2008) incorporates lakes, streams and wetlands for which the primarily value is conservation. The conservation policies provide a range of uses that is generally secondary to the value of conservation. These uses are specific to the water body considered (as listed in the code) and can include recreation, discharge of waste/stormwater, water supply (including domestic supply and stream flow Part A (1) objectives The objectives of the conservation catchment policies are to: Protect and conserve the water quality and aquatic habitats of highly valued lakes, rivers and streams; Make provision for a range of other water uses and environmental values that are compatible with the conservation values of the catchment; Ensure that water and catchment land uses are consistent with maintaining ecological sustainability and the conservation values of the catchments; 30 WATER SECURITY MAJOR PROJECTS JULY 2009

5 Ensure that the streamflow and quality of discharge from the catchment are consistent with the protection of environmental values of downstream waters; and Protect and conserve the water quality of groundwater resources of the Territory. The ECD proposal is consistent with these objectives in that it: Will have higher water quality than the existing reservoir (refer to section 6.1.3, pages of the approved EIS for further details) and we are proposing artificial habitats and riparian vegetation offsets for areas that will be permanently impacted upon; Is consistent with the values and uses of this policy (as described below); The ECD will continue to be operated and managed as a potable water supply dam (as per NCP and Territory Plan regulations). Management of the catchment will continue under the Lower Cotter Catchment Strategic Management Plan. On this basis and as described in the ECD EIS the ECD project can be delivered in an ecological, responsible and sustainable manner; Will maintain the regulatory requirements as described in section (page 138) of the approved EIS in relation to environmental flows in the Lower Cotter River; and Will not adversely impact on the quality of groundwater resources in the Territory. These matters were specifically addressed in the EIS at chapters 4, 5 and 6. The Code includes the following policies that should be considered in this application Part A (2) Policies Element 1: Water use and environmental values Water within the conservation catchments may only be used for the purposes in Schedule 1 of the code in accordance with the water uses and environmental values set out in Schedule 2. Schedule 2 of the code sets out the uses permitted in the various conservation catchments that meet the requirements of the code. The ECD is not located in any of the conservation catchments listed in Schedule 2 of the code. The section of the Cotter River below the existing Cotter Dam to the Murrumbidgee River may be used for views of the waterscape, protection of aquatic habitat low land streams; water-based recreation activities (including boating and swimming) and hydro electric generation. None of the activities proposed in the ECD proposal will permanently impact on any of the uses listed. Any impacts on these uses during construction of the ECD will be managed under the CEMP. Element 2: Protection of water quality Rules/criteria a) Land water use and protection measures shall be consistent with maintaining the water quality appropriate to the relevant water uses and environmental values set out in Schedule 2. b) Land use and management provisions shall be consistent with land use capability. c) Land use development and management provisions shall be consistent with minimising erosion and discharge of sediments. d) Provision shall be made for the collection treatment of domestic and industrial liquid wastes. e) Provision shall be made for the collection and treatment of urban stormwater pollutants. f) Recreation areas shall be located in zones in which the water quality is consistent with the water quality criteria for the protection of the prescribed water use. g) Total discharge (loading) of various constituents emanating from the catchment shall not exceed the sustainable loading on receiving waters. h) Discharge of wastewater shall not be permitted to groundwater resources. The ECD proposal will have higher water quality than the existing reservoir (refer to section 6.1.3, pages of the approved EIS for further details) and is not located in any of the conservation catchments listed in Schedule 2 of the Code. The proposal is compatible with land use and management provisions in the catchment. A Progressive Erosion and Sediment Control Plan is included as part of this DA submission (see drawing BWA-ECD-EN-ESP-001-0). The Progressive Erosion and Sediment Control Plan should be considered in the context of the CEMP and its sub-plans and to facilitate this, the proponent has included the draft Soil and Water Quality Plan in this application. The Soil and Water Quality Plan is part of the CEMP and will be implemented in conjunction with construction activities commencing on site; and See section (pages ) of the completed EIS for general details on sediment and erosion control measures proposed. Also review the Progressive Erosion and Sediment Plan in light of the draft Soil Water Management Plan submitted with this DA submission. ACTEW will adopt best practice management measures as detailed in the Development Control Code for Best Practice Waste Management in the ACT throughout the construction phase of the ECD project; and Waste Management will be conducted under a Waste Management Plan that will be embedded into the approved CEMP for the project. To facilitate the assessment of this submission a draft copy of this plan is included. Not relevant to this proposal. Not relevant to this proposal. Separate DAs will be submitted for the viewing platform and alternative recreation area proposals. Water quality will be managed in accordance to requirements negotiated with the regulator. The proposal will not discharge wastewater into groundwater resources. ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 31

6 Element 3: Protection of streamflow Rules/criteria a) Streamflow diversions shall be restricted to authorised diversions. b) Lake and reservoir releases shall be consistent with the protection of downstream ecology and water uses. With regard to construction impact a flow diversion system will be built to direct normal stream flows and environmental flows through the construction site. The diversion system will consist of an upstream coffer dam which directs flows into a pipe which passes through the construction area before discharging into the Cotter River downstream of the construction site. This arrangement ensures that there is no possibility of contaminating the Cotter Reservoir with water from downstream. See section (page 138) of the completed EIS for further details; and Streamflow from the completed ECD (permanent) will be managed in accordance with e-flow and other regulatory requirements as negotiated with the Territory (EPA and others). The ECD is designed to allow e-flow releases through all operational scenarios and will be able to meet future requirements that the Territory may impose. A reduction in environmental flow volumes may be required during foundation works and will be the subject of a separate submission to the EPA. There will be a short period between six to eight months where no diversion will be in place during foundation works however the existing reservoir water level will be regulated via a water supply extraction pipeline. Groundwater that would have discharged to the existing Cotter Dam reservoir will continue to discharge to the new reservoir. Consequently, the ECD will have minimal effect on the baseflow discharge from the aquifer above the dam as it is already discharging to the existing reservoir. An enlarged dam will cause the hydraulic gradients in the vicinity of the dam to flatten slightly and thus bring the watertable marginally closer to the surface. This might lead to changes in vegetation on the fringes of the dam. However, these vegetation changes will be masked by more intense changes due to proximity to water. 32 WATER SECURITY MAJOR PROJECTS JULY 2009

7 Element 4: Protection of stream environs Element 5: Protection of Ground Water Yield Rules/criteria Rules/criteria a) Land uses and protection measures within stream environs and floodplains shall be consistent with the protection of the floodplains. b) Sand and gravel removal and channel stabilisation works may be undertaken as required to rehabilitate and stablise aquatic habitats and flood channels. The ECD is designed to meet a higher safety rating than is strictly required. This feature will ensure that downstream environs and floodplains are effectively protected (see section , pages of the approved EIS). All construction works (including works within the waterway) will be conducted in accordance with a full set of environmental approvals in place. These approvals include a completed EIS, development approval, approved CEMP, approved environmental authorisation, and an approved Waterway Works License. Quarry areas, when construction is complete, will be rehabilitated to a state that is consistent with enhancing fish habitat in the enlarged reservoir (refer to drawing GHD-ECD-DAM-GN-SKT-1025). a) The abstraction of groundwater shall be consistent with authorised abstractions. No groundwater abstraction is proposed as part of this project Part B: Water supply catchments The Water Supply Catchments incorporates those reservoirs and streams for which the primary value is domestic water supply. The Water Supply Catchment policies allow for a range of other uses, which are generally compatible with but secondary or ancillary to the primary value Part B (1) objectives The objectives of the water supply catchment policies are to: Make provision for domestic water supply as the predominant water use; Ensure that water and catchment land uses are consistent with maintaining a safe and reliable water supply (protection of quality and quantity) and other values of the catchment; Make provision for a range of other water uses and environmental values that are compatible with use of the water for domestic water supply; Ensure that the streamflow and quality of discharge from the catchment are consistent with the protection of environmental values of downstream waters; and Protect and conserve the water quality of groundwater resources of the Territory. The ECD proposal is consistent with these objectives in that it: Is a clean water supply storage reservoir, Will be managed to ensure safe reliable drinking water for the ACT and region, The proposed use of the proposed site for water supply uses are consistent with the values and uses of this policy (as described below); Will maintain the regulatory requirements as described in section (page 138) of the approved EIS in relation to environmental flows in the Lower Cotter River; and Will not adversely impact on the quality of groundwater resources in the Territory. These matters were specifically addressed in the EIS at chapters 4, 5 and 6. The code includes the following policies for water supply catchments that should be considered in this application: Part B (2) policies Element 6: Water use and environment values Water within the water supply catchments may only be used for the purposes in Schedule 3 of the code in accordance with the water uses and environmental values set out in Schedule 4. Schedule 4 of the code sets out the uses permitted in the various water supply catchments that meets the requirements of the code. The ECD is listed in Schedule 4 of the Code whereby domestic water supply, waterscape and aquatic habitats mountain streams uses are allowed. None of the activities proposed in the ECD proposal will permanently impact on any of the uses listed. Any impacts on these uses during construction of the ECD will be managed under the CEMP. ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 33

8 Element 7: Protection of water quality Rules/criteria a) Land water use and protection measures shall be consistent with maintaining the water quality appropriate to the relevant water uses and environmental values set out in Schedule 4. b) Residential use and camping shall be excluded from the catchment. c) Discharge of wastewater shall not be permitted within the catchment. d) Construction activities shall be consistent with minimising erosion and discharge of sediments. e) Recreation activities shall be controlled to minimise the potential of pollution of waters. f) Total discharge (loading) of various constituents emanating from the catchment shall not exceed the sustainable loading on receiving waters. g) Discharge of wastewater shall not be permitted to groundwater resources. The ECD proposal will have higher water quality than the existing reservoir (refer to section 6.1.3, pages of the approved EIS for further details) and is not located in any of the conservation catchments listed in Schedule 2 of the code. Not relevant to this proposal. Residential use or camping not proposed. No wastewater discharge is proposed as part of this proposal. Water from the Cotter Reservoir will be used for the following construction purposes: Production of RCC and conventional concrete (batch plant); Dust suppression on roads and quarrying activities; Damping down aggregate stockpiles to condition and cool it prior to mixing; Curing and cleaning RCC surfaces; Moist curing all concrete; Grouting foundations; Roadworks and bulk earthworks; and Quarrying and crushing activities. Water used in all processes will be drawn from the Cotter Reservoir rather than the Cotter River; Water drawn from the Cotter Reservoir will be stored in holding dams within the construction area; Evaporation blankets will be installed (if practicable) on these dams to minimise water loss. To minimise consumption, water will be reused where practicable and feasible. For example, water from sediment basins can be treated and reused on site for dust suppression and compaction purposes; and Table 5.2 (page 139) in the approved EIS details the approximate quantities of water to be used during the construction of the Cotter Dam. Not relevant to this proposal. There will be no recreation allowed in the reservoir. Separate DA will be submitted for the viewing platform and the alternative recreation area proposals. Water quality will be managed in accordance to any specific requirements that the regulator may impose. Wastewater will not be disposed of into groundwater. Wastewater from construction activities will be treated in sediment ponds and coffer dams. This water will either be used on site (e.g. dust suppression) or treated to levels negotiated with the EPA prior to discharge into the Cotter River downstream of the works area. 34 WATER SECURITY MAJOR PROJECTS JULY 2009

9 Element 8: Protection of streamflow Rules/criteria a) Streamflow diversions shall be consistent with authorised diversions. b) Reservoir releases shall be consistent with protection of downstream ecology and water uses. c) Sites shall be established as required to provide storage and maintain supply during extended drought periods. With regard to construction impact a flow diversion system will be built to direct normal stream flows and environmental flows through the construction site. The diversion system will consist of an upstream coffer dam which directs flows into a pipe which passes through the construction area before discharging into the Cotter River downstream of the construction site. This arrangement ensures that there is no possibility of contaminating the Cotter Reservoir with water from downstream. See section of the completed EIS for further details; and Streamflow from the completed ECD (permanent) will be managed in accordance with e-flow and other regulatory requirements as negotiated with the Territory (EPA and others). The ECD is designed to allow e-flow releases through all operational scenarios and will be able to meet future requirements that the Territory may impose. A reduction in environmental flow volumes may be required during foundation works and will be the subject of a separate submission to the EPA. There will be a short period between six to eight months where no diversion will be in place during foundation works however the existing reservoir water level will be regulated via a water supply extraction pipeline. The ECD is designed to allow effective management of water quality to ensure protection of downstream ecology and water uses. This includes design features such as de-stratification units, multi-level intake structure and reservoir operation that is optimised to prevent coldwater pollution and other related impacts. See sections 6.2 of the approved EIS. The ECD is part of ACTEW s bulk water security strategy for the ACT and region. The construction of the ECD will allow an extension of the existing water supply storage capability, assisting in drought proofing the ACT. The broader ACTEW strategy (that includes the ECD) took into account a range of climatic outcomes (including a worst case climate change scenario for 2035). The broader strategy will guarantee supply of drinking water through extreme periods of drought, such as the current drought experienced. ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 35

10 Element 9: Protection of stream environs Rules/criteria a) Land uses and protection measures within the reservoir and stream environs and floodplains shall be consistent with the protection of the floodplains. The ECD is designed to meet a higher safety rating than is strictly required. This feature will ensure that downstream environs and floodplains are effectively protected (see section , page of the approved EIS). Element 10: Protection of groundwater yield Rules/criteria a) Abstraction of groundwater shall be consistent with authorised abstractions. No groundwater abstraction is proposed as part of this project Part C: Drainage and open space catchments Drainage and open space catchments incorporate those lakes and streams for which the primary value is drainage of the catchment and associated provision of open space. The drainage and open space catchment policies allow for a range of other uses, which are generally compatible with but secondary or ancillary to the primary use. Part C of the Water Use and Catchment General Code is not applicable to this proposal as the Cotter Catchment is not listed as a catchment in Schedule 6 which defines the area of interest for this area of the code. 36 WATER SECURITY MAJOR PROJECTS JULY 2009

11 8 Other government plans 8.1 Management plans Part 10 of the Planning and Development Act 2007 makes provision for land within the ACT to be reserved as public land for various purposes. Land that is reserved as public land is identified by an overlay on the Territory Plan. All land, reserved as public land, is required under the Planning and Development Act, part 10.3 to be managed under a management plan developed for the land. Both the Murrumbidgee River Corridor and parts of the Lower Cotter Catchment are identified as public land. The significance of each plan in relation to the enlargement of the Cotter Dam is described in detail in the completed ECD EIS. The ECD proposal is consistent with the objectives/provisions of the Murrumbidgee River Corridor Plan and Lower Cotter Catchment Strategic Management Plan. The proposal (as described in the completed ECD EIS) will be implemented within the framework of a CEMP that will allow for the management and mitigation of the main construction impacts. A summary of the relationship between the ECD and management plans are included below. Please refer to section (page ) of the completed EIS for more detail River corridor management plan The Murrumbidgee River Corridor Management Plan (January 1998) (MRCMP) provides the policy framework for consideration of the impacts of the construction on the conservation and riparian management of the Murrumbidgee River. In particular the management plan addresses the management issues, objectives, policies and procedures specific to the corridor. It is consistent with the National Capital Plan and the Territory Plan. The Murrumbidgee River corridor is managed by TaMS in accordance with the management plan. With respect to utilities, a number of specific management objectives are prescribed. These include: To minimise any adverse effects on corridor values resulting from utility installations or service operations; To coordinate the operational requirements of utilities with other management programs; To aid the legitimate operation of utilities and services; and To maintain liaison between the service and other authorities with operational responsibilities in the corridor 4. The service (now TaMS) will liaise with all utilities operating in the corridor, and seek to negotiate management agreements with them, which will include: The precise description of facilities, works operations and access routes covered by the agreement; Conditions for clearing vegetation and applying chemicals, such as herbicides; Requirements for soil conservation and rehabilitation works; Protection of natural and cultural heritage sites; Requirement for all staff, contractors and subcontractors to comply with the management plan and relevant legislation under the Nature Conservation Act; Responsibility for removal of equipment and installations that may no longer be required; and Decisions about new or modified utilities like the ECD will be based on the following criteria: Whether there is a prudent or feasible alternative to its location within the corridor; Impacts on the landscape, natural and cultural environment and recreation opportunities, both within the corridor and elsewhere, are minimised, and that a decision on the project is based on an appropriate documentation and evaluation of such impacts, and of alternatives; Impacts on public health are considered and minimised; Sites of natural or cultural significance are not compromised, and disturbance to natural habitat areas is minimised; Existing utility easements, locations or routes are used as far as possible; Soil cover and water quality will be protected during construction, and that long-term land rehabilitation and management is provided for; and Maintenance has been considered. The proposal is consistent with the requirements of the MRCMP Lower Cotter Catchment Strategic Management Plan Department for Parks Conservation and Lands is the custodian and land manager of the Cotter Catchment and have adopted (among other documents) the Lower Cotter Catchment Strategic Management Plan in 2007 to assist in the management of the catchment. The management plan aims to: Restore the Lower Cotter Catchment to a natural and stable condition that supports the delivery of clean water and that also allows for a range of activities that are compatible with the protection of water resources. The plan recognises the importance of the Lower Cotter Catchment (LCC) as a water supply catchment for Canberra and sets out the framework for the management of the catchment and activities therein and use thereof in light of a number of strategic requirements, including domestic water supply. The purpose of the management plan is to define land uses, strategic directions and management objectives, and to provide a management framework to ensure long-term stability of landscapes and security of water quality and supply. The importance of the protection of the catchment and the relationship between land management and water quality is acknowledged as being important for the future Cotter Reservoir. ACTEW, PCL and Environment ACT have been working together on remediation of the catchment post the 2003 bushfires by taking actions such as revegetation/rehabilitation of burned/impacted areas, improvement of roads and introducing erosion control measures to meet objectives of the management plan. ACTEW will continue to support TaMS with the management of the catchment into the future. Recreation within the catchment and in the reservoir has the potential to impact upon the quality of the water within and downstream of the reservoir. The management plan states, Access to the Cotter Dam for water-based recreational activities will not be permitted ; it also commits to developing a recreation strategy for the catchment. The ECD proposal does not propose any inclusion of water based recreational use of the future Cotter Reservoir. Management procedures for continuing liaison and coordination of management operations. 4 The Murrumbidgee River Corridor Management Plan refers to ACT Parks and Conservation Service, now TAMS Parks Conservation and Lands ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 37

12 9 Statement of environmental effects 9.1 Introduction An assessment of environmental effects of a proposal is one of the requirements of the Territory Plan Non-Urban Zones Development Code (March 2008), Part B General Development Codes, Criteria 17. This criterion states that the application for development must be accompanied by an assessment of environmental effects. This requirement is mirrored in Section 120(f) of the Planning and Development Act The statement below has been prepared to serve this purpose. 9.2 Assessment of environmental effects Criteria 17 (C17) of the Non-Urban Zones Development Code require the preparation of an Assessment of Environmental Effects of the ECD DA proposal. C17 requires, but is not limited to, assessing the following matters: a) The amount of traffic likely to be generated and the likely impacts on the roads system; b) Impacts on the amenity of the surrounding land uses; c) Impacts on the role and character of the hills and ridges as a visual backdrop; d) Impacts on rural character; e) Provision of landscaping; f) Impacts on water supply catchments; and g) Impacts on earthworks or rehabilitation works on soil stability and quality. Most of these matters were considered in chapters 5 and 6 in the completed EIS and the Section 224 Notice submission (included with this DA). For this application the above effects are again considered in turn in the proceeding sections. These statements should be read in conjunction with the relevant sections of the completed EIS. 9.3 Impacts of development on traffic ACTEW has commissioned a traffic impact assessment for the ECD project as part of the EIS preparation, to consider the likely impacts on the road network proposed to be used for this project and in particular, road impacts on Cotter Road associated with construction activities. The full traffic impact assessment and the description of the impacts are included at Appendix U and section 5.1 (pages ) of the completed EIS (included with this submission). Below is a summary of the main findings of the assessment. The impacts associated with the increase in traffic generated from the proposal are considered to be minimal and temporary in nature, and related to: Construction traffic; and Vehicle parking for construction workers. The main roads that are likely to be impacted upon by the construction of the dam are Cotter Road, Brindabella Road and Paddy s River Road. Primary and secondary access routes are proposed for entry and exit to the construction site (refer to drawings GHD-ECD-DAM-GN-SKT-1002, GHD-ECD-DAM-GN-SKT-1030 and GHD-ECD-DAM-GN- SKT-1031). The primary access route will be via Paddy s River Road and the secondary access route will be via Brindabella Road. These routes will be utilised for oversized loads. The main traffic generated through the construction phase would be from equipment and material deliveries, such as: Construction materials (e.g. sand deliveries); Construction equipment and machinery; Specific components for the dam; and Movement of construction personnel, including contractors, site labour force and supervisory personnel. (See section of the completed EIS) The main impact on Paddy s River Road will be for the intermediate phase (refer to section 3.3 of this report). The worst-case scenario outlined in the traffic assessment predicts that heavy vehicle traffic generation during the weekday could be in the order of 166 trucks per day (83 trucks to and from the site) (refer to section 5.1.3, pages of the completed EIS for a detailed definition). The proportion of these movements occurring during the AM and PM peak periods is conservatively estimated at approximately 25 per cent, with a split between arrivals and departures of 50/50. Therefore, the worst-case scenario that truck movements occur during the AM and PM peak periods is 42 vehicles per hour, comprising of 21 arriving and 21 departing. For light vehicles, it is likely that the arrival of workers for the day shift will occur before the AM peak hour and departure would be after the PM peak hour. For the night shift, the arrival of workers will coincide with the afternoon peak and the departure will be before the morning peak. Therefore, the proportion of these movements occurring during AM and PM peak periods is conservatively estimated at approximately 30 per cent with the total daily arrivals being 190 in and 190 out. Based on this assumption, the weekday peak traffic generation will be in the order of 57 additional vehicles trips per hour. The traffic volume will be distributed among the three access routes. The traffic assessment found that the additional volume of light vehicles and heavy vehicles is unlikely to impact on the existing road network operations in terms of roadway capacity since the roads have adequate spare capacity beyond the additional volume (refer to the Traffic Impact Assessment at Appendix U of the completed EIS). It is anticipated that the construction activity would occur over a period of approximately 24 months (section of the completed EIS and the 224 Notice Submission). The assessment showed that there is adequate capacity on Cotter, Brindabella and Paddy s River Road to accommodate the predicted increases associated with construction traffic. The increases in traffic will be managed under a Traffic Management Plan that will be included in the CEMP for the site. The traffic study also showed that where construction traffic is to be added to special events traffic, it is likely that certain sections of the Cotter Road will experience delays and the potential risks for collisions could increase if traffic management measures are not adopted. In response to this ACTEW included a commitment to prepare (in consultation with Roads ACT) and adopt a comprehensive Traffic Management Plan as part of the CEMP to address specific arrangements for traffic routing and priority flows during general traffic as well as special event traffic periods. The mitigation measures to be included within the approved Traffic Management Plan are outlined in section of the completed EIS The traffic impacts associated with construction of the ECD will be mitigated by implementing a Traffic Management Plan as part of the CEMP. This plan will include details relating to sharing of roads, safety measures that will be implemented and measures for the management of traffic during special events. Operation of the ECD will not generate traffic over and above the volumes being generated by the existing Cotter Dam. There will be no significant increase in traffic impacts from operation of the ECD in the future post construction. All sections of public roads directly impacted upon during construction of the dam will be restored to their current state once construction is completed. Prior to the affected roads being used, the proponent will prepare a conditions audit. This report will form the basis of any remediation works required post construction. 38 WATER SECURITY MAJOR PROJECTS JULY 2009

13 9.4 Impacts on surrounding lands and land uses The likely impacts on the amenity of the future ECD surroundings are minimal and are related to the following: Heritage; Vegetation clearing and visual impacts relating to additional structures within the area (amenity); Temporary noise impacts during construction (amenity); and Recreational access (Reservoir, Cotter Avenue and Paddy s River Tourist Drive Five). The likely impacts on these matters are described in the completed EIS at Chapter 5.0. The EIS proposed mitigation and management measures to ensure that any impacts on matters of amenity are successfully managed throughout the construction period. There are no long term (permanent) impacts on amenity predicted with this proposal Impacts on heritage ACTEW commissioned an assessment of the potential impacts that may result with the proposed footprint of the new reservoir inundation area as well as the construction of the ECD on Indigenous and non-indigenous archaeological and cultural heritage values, as defined under both Commonwealth and ACT environment, heritage and planning legislation. The assessment report was prepared by a qualified heritage consultant and is presented in section 6.9 (pages ) and Appendix M of the completed EIS and includes a review of existing information sources and heritage registers, consultation with ACT Representative Aboriginal Organisations (RAOs), archaeological field survey of potential inundation and construction impact areas, and an analysis of collected data. The assessment predicts that the archaeological resource is likely to be very low in density and artefact numbers, discontinuous, and largely present on the surface as opposed to subsurface deposits. It concludes that it is unlikely that the predicted resource within the extended area would pose a permanent constraint to the proposal. The assessment recommends that the management strategies presented in the EIS remain appropriate in addressing the potential impacts of the proposal under review and suggests that a comprehensive surface archaeological survey of this new area be conducted and any sites found be considered, along with all other ECD sites subject to impact. A Conservation Management Plan (CMP) was submitted to the Heritage Council on 7 May The Heritage Unit is currently considering the final CMPs and a decision is expected early July The implementation of the CMP will ensure that matters of Heritage significance are managed adequately and appropriately in accordance with the requirements under the Heritage Act Vegetation clearing and visual impacts The construction of the ECD will result in the temporary and permanent loss of vegetation from the Lower Cotter Catchment. The permanent vegetation loss is associated with the future expansion of the inundation area that is associated with the future full supply level of the ECD. The impact of the permanent loss of vegetation is that of a replacement with water views an impact that is considered to be acceptable in the context of the surrounding land uses and the use objectives of the Lower Cotter Catchment in the NCP and Territory Plan. The construction works will result in temporary vegetation loss from the areas that will be used for the construction of the main engineering infrastructure. Clearing of vegetation will have an impact on the visual amenity from surrounding lands. Disturbance of vegetation at the construction site will be mitigated partly by conducting rehabilitation works in these areas (described in section of this report) as well as providing offset works at the same ratio as permanently disturbed vegetation. The visual impact in Appendix G of the EIS provide an indication of the likely visual impacts that may result from construction activities associated with this proposal and indicate the likely result post rehabilitation allowing some time for establishment. There will be permanent scarring associated with vertical rock cuts required in construction of access roads. Figure 9.3 View from Camp Cottermouth, five years post construction ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 39

14 Figure 9.4 View from Moore s Hill, five years post construction The construction area is expected to recover quickly once rehabilitation works have been completed. Early rehabilitation will be investigated and implemented at the earliest opportunity to allow maximum recovery time and to provide natural screening of impacted areas to develop progressively as construction work continues. The strategy to mitigate visual impacts is described in drawings GHD- ECD-DAM-GN-SKT-1033 and GHD-ECD-DAM-GN-SKT-1034 and the draft Landscape Rehabilitation Management Plan. Visual impacts resulting from the works associated with dam construction will extend beyond the immediate surrounds of the dam. A visual impact assessment is presented in section (pages ) and Appendix G of the completed EIS. Table 5.4 and Table 5.5 in the completed EIS identify the construction and operation impacts from the proposed works from each sensitive visual receptor and view point. To assess the extent to which the new engineering infrastructure and the new water level are likely to be visible from surrounding areas, a viewshed has been developed and adopted as an assessment tool. With respect to the main dam and saddle dam, the proponent acknowledges that these are substantial structures and the visual treatment is considered important. With regard to the main dam the visual impact has been mitigated through design in both the vertical and horizontal planes with the inclusion of the stepping in the RCC structure as well as the inclusion of the main spillway as a vertical structure breaking up the expanse of the face. Other design features including the stepping between the nonoverflow section, secondary and primary spillways, as well as the inclusion of changes in direction of the RCC stepping for the abutment return channels and inclusion of training walls will provide further relief (refer to main wall detail and downstream elevation drawings drawings GHD-ECD-DAM-GN- SKT-1003, GHD-ECD-DAM-GN-SKT-1005, GHD-ECD-DAM-GN-SKT-1013 and GHD-ECD-DAM-GN- SKT-1014). The design of the saddle dams utilises natural materials (primarily rock see drawing GHD-ECD-DAM-GN-SKT-1027). With these materials being obtained onsite these structures will be in keeping with the natural surrounds including colours and tones of the surrounding area. The rock used will be primarily fresh rock that will change colour over time due to natural weathering processes. As described in the EIS, impacts on visual amenity of the surrounds from construction of the ECD will be managed by adopting measures including the following (as required): 40 WATER SECURITY MAJOR PROJECTS JULY 2009

15 Land disturbed by construction activities located above the new inundation zone will be rehabilitated. Rehabilitation works will include re-profiling the surface to provide visual interest and undertaking revegetation works; Design and construction will be undertaken to minimise earthworks and hence impact on the landscape; Abutments will be treated to minimise the visual prominence of excavation work required for dam wall construction; ACTEW will construct a viewing platform, with interpretive information, to enable visitors to view the dam construction works and dam wall after construction; and Interpretive information and education will be provided to inform the public of construction progress and changes to the visual landscape Temporary noise impacts during construction. ACTEW Commissioned an acoustic assessment to investigate the likelihood and extent of noise and vibration impacts associated with the ECD proposal (refer to Appendix H and section 5.5.5, pages of the completed EIS and the 224 Notice Submission for details). The assessment included Acoustic modelling of construction activities in relation to nearby potentially noise sensitive receivers and included assessment of impacts associated with road traffic noise, 24-hour construction operations and blasting audibility. It also considered noise associated with the operation this dam and no noise impacts were identified. The acoustic modelling indicated that noise from construction activities are below daytime emission criteria at Uriarra Village, the Pierces Creek Settlement, the Greenhills Camp and Conference Centre, and the residence at Casuarina Sands. Noise levels exceed the criteria at the residence at Cotter Avenue. Other sensitive receivers identified as a potentially significant impact (during nightime 24 hour construction) include the remaining residents at Pierces Creek and the PCL ranger s house adjacent to the Cotter Pump Station. The proponent is currently in discussions with the custodians of these properties, exploring opportunities to manage the construction impacts, any measures specifically required to manage the impacts on these residents will be implemented prior to construction works commencing and are included in a Noise Management Plan. A number of mitigation measures are included within the completed EIS to manage noise impacts. These include: Preparation of a Noise Management Plan as part of the CEMP (a draft Noise Management Plan is included with this submission); Limiting construction activities to the general working hours of 6am to 6pm on Monday to Friday and 7am to 4pm on Saturday, excluding public holidays (with the exception of the 24 hour/7 days a week activities described in section of this report); Implementing all relevant noise reduction methods of AS 2436: Guide to noise control on construction, maintenance and demolition sites; ACTEW to negotiate directly with the owner and occupant of the residence at the Cotter Avenue in relation to construction noise and blasting issues; ACTEW to resolve any issues surrounding the necessity of night time concrete placement work and associated noise; Noise monitoring will be undertaken; Special conditions associated with night time truck deliveries include consideration of limiting or excluding the use of compression breaking and reducing speed within close proximity of residents; and Ongoing community consultation and complaints management system Recreational access (Reservoir, Cotter Avenue, Paddy s River Tourist Drive Five) The construction of the ECD project will provide viewing and educational opportunities to the population of Canberra. Given its close proximity to the site ACTEW is anticipating that there may be extensive interest in the construction of this major utility infrastructure. In order to meet the likely demand for viewing and manage visitors and traffic and education ACTEW will develop viewing opportunities with interpretative signage. This initiative will be supported with a full time community engagement plan that will be rolled-out continuously during the construction of the project. The works associated with this will be progressed in parallel with this proposal (as outlined in the Master Plan drawing GHD-ECD-DAM-GN-SKT-1044). During the construction period there may be some negative impacts, particularly to specific groups including recreational users and those who use the Cotter Road to access their properties. Large family, sporting and community groups seeking a riparian picnic experience or recreational activities will have restricted access to Cotter Avenue during the construction period. Given the scale of the likely impact associated with the construction of the dam ACTEW is proposing to close Cotter Avenue for the duration of construction. The closure of the avenue will be scheduled to commence once the alternative recreation area upgrade has been completed and is scheduled for late The Avenue will be re-opened once the construction of the ECD project are completed (expected for 2011). Impacts on the Cotter recreational precinct in general during construction will be managed in accordance with activity specific management plans in the CEMP e.g. traffic management, noise management and the like. A Tree Assessment (included with this submission) has also been prepared to inform the landscape and construction management of Cotter Avenue in relation to construction works and recreational works that form part of the ECD project (also refer to drawings GHD-ECD- DAM-GN-SKT-1035 to GHD-ECD-DAM-GN-SKT-1043). During the early stages of construction Cotter Avenue will be used for materials delivery and other construction traffic. This is mainly associated with the construction of flow diversion and sediment erosion control infrastructure installation. Cotter Avenue will be used for these activities until such time as the main haul road to the construction site has been completed. The Traffic Management Plan will include specific measures to ensure that traffic is managed safely through the Avenue during this period. Any impacts on Cotter Avenue from the passing of construction traffic will be remediated prior to the precinct being reopened. The remediation work will ensure that Cotter Avenue is returned to a state equal to current or better prior to reopening. Recreation areas in the precinct surround Cotter Avenue will be protected from construction activities as detailed in the landscape management and protection plan drawings GHD- ECD-DAM-GN-SKT-1035 to GHD- ECD-DAM-GN-SKT It is anticipated that road users such as cyclists, motorcycle riders, horse riders, general Cotter Road traffic and land owners accessing their properties along Cotter Road will be most affected by changed traffic arrangements. The completed EIS acknowledges these impacts, although they will be for only a relatively short time period. Details on these impacts are further described at sections 5.1 (page ) and 6.11 (pages ) of the completed EIS. These impacts will be managed under an approved Traffic Management Plan that will be included in the CEMP. Undertaking blasting between 9am and 5pm Monday to Friday and 9am and 1pm Saturday; Conducting all blasting activities by a licensed blasting contractor and in accordance with an approved Blasting Plan; ACTEW to provide advance notice to sensitive receivers of scheduled blasting activities; ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 41

16 9.5 Impacts on role and character of hill and ridges as visual backdrop As noted in section 7.4 of this report, the site lies within a landscape that provides contrasting visual experiences, from the mountains of the Brindabella Range to the west, the fire-affected forestry area in the lower catchment, the Cotter, Paddy s and Murrumbidgee Rivers below the dam, and the recreation areas characterised by large established avenue trees. The character of the hills and ridges will not be significantly altered as a consequence of this project. The impacts are minimal and related to: Landscape at locality; and Visual impact at locality and from surrounding lands. Landscape and visual impacts are discussed in detail in section and (page ) of the completed EIS (included with this submission). 9.6 Impacts on rural character There are no significant impacts on rural character from this proposal. This development does not constitute urban development in terms of residential or commercial uses. The use of utility infrastructure (that includes a water storage reservoir) is allowed in the applicable land use zones impacted upon. The use of the Lower Cotter Catchment for water supply purposes is acknowledged in the National Capital Plan, Territory Plan and Lower Cotter Catchment Strategic Management Plan. In light of these instruments of management this proposal is consistent with the character of the catchment. Details with regard to the impact on the regulatory status of the land are detailed in Chapter 4 (pages ) of the completed EIS (included with this submission). 9.7 Provision of landscaping The impacts are: Visual (at a localised level); Largely temporary (in relation to construction works); and Restorative. Visual impacts are described above and detailed in the landscape and visual assessment provided in Appendix F and G of the completed EIS (included with this submission). The Lower Cotter Catchment has been significantly impacted upon by the 2003 bushfires and is still highly disturbed over large tracts of land (this land is showing signs of regeneration). ACTEW is proposing to conduct offsets and rehabilitation (as described in section of this report) in compensation for the loss of native and former pine vegetation. The offset ratio proposed is 2:1 for the loss of native vegetation and 1:1 for impacts on former pine plantations. ACTEW will negotiate the locations of the final offset sizes (based on actual impacts) the delivery mechanisms and locations with the custodian of the land, PCL. Offset works is likely to lead in the medium term to an increase in amenity (primarily visual) as the works assist an increase in quality of the natural vegetation and landscape in areas identified to receive offset works. 9.8 Impacts on water supply catchments Impacts on ACT water supply catchments will be limited primarily to the Lower Cotter Catchment. There may be offset works conducted in other water catchments (dependant on negotiations with the TaMS (PCL)) which will be beneficial in nature. The Cotter Catchment can be broken up into three broad sub-catchments based on the locations of the three existing water supply dams (Corin, Bendora and Cotter). The Lower Cotter Catchment is the main supply area for the proposed ECD. Just under 50 per cent of the lower Cotter Catchment is drained by two major tributary systems (Condor and Pierces Creeks) that enter the Cotter River in the lower landscapes within the inundation area of the proposed expanded reservoir. Both these drainage systems have been heavily impacted by previous plantation forestry activities in the catchment. The management of the Lower Cotter Catchment will continue to be managed in accordance with the Lower Cotter Catchment Strategic Management Plan. This will remain the responsibility of TAMS. ACTEW will continue to support initiatives to improve the management of the catchment to achieve water supply outcomes. Undertaking large scale construction works are often associated with a risk of erosion and sediment release from the works site onto surrounding land and water bodies. These risks are commonly mitigated by standard sediment and erosion management measures. Uncontrolled sediment run-off from the construction site could impact on water quality in the Cotter Reservoir and River. Site-specific sediment control plans will be prepared for all areas of the work site. They will be prepared to the requirements of Environment Protection Authority before construction activity begins, but will be amended progressively to accommodate changed construction activities, landforms, drainage paths and other conditions. A Progressive Sediment and Erosion Control Plan (drawing BWA-ECD-EN-ESP-001-0) is included with this submission. Specific erosion and sediment control plans will be prepared for: Defined stages of construction (for example, batch plant establishment and quarry activities); Areas of high-erosion hazard (for example, working in waterways, coffer dam installation and establishment); and Specific works that occur outside the main construction site. The erosion and sediment erosion control plans will be included in the EMP for the site. 9.9 Impacts of earthworks or rehabilitation works on soil stability and quality Undertaking large scale construction works are often associated with a risk of erosion and sediment release from the works site onto surrounding land and water bodies, as well as weed management issues. The impacts on soil stability identified are: Erosion and sedimentation; and Weed management. Though not an impediment to the construction of the dam, weeds in the Lower Cotter forestry estate continue to be a problem, negatively impacting on the landscape. A large variety of exotic plants occur throughout the study area. Infestations range from just a few individually affected small areas to almost complete dominance. Infestations generally correlate to previously disturbed areas such as former pine plantation (although some patches within these areas showed good recovery of native groundcover and shrub species). A wide range of noxious (pages ) and environmental weeds were encountered in the study area (described in section of the completed EIS). The former pine plantations are the worst affected areas, illustrated by the mapping of high and low conservation values in Figure 6.4 (page 213) of the completed EIS. Other affected areas occur along roads and access tracks, and in the Cotter and Casuarina Sands reserves. This infestation will require the continuation of weed control programs under the scope of the ACT Weed Strategy. The management of the lower Cotter Catchment by PCL, in accordance with the Lower Cotter Catchment Management Plan, will also be a key to ensuring appropriate weed 42 WATER SECURITY MAJOR PROJECTS JULY 2009

17 management. Weed management within areas that will be impacted upon by construction activities is described in the draft Landscape Rehabilitation Management Plan. Management measures to prevent the spread of these noxious species into areas of low infestation will include cleaning tyres, wheel guards and bases of machinery and vehicles before entering weed free areas. The use of sterile, clean seed in re-vegetation efforts will also assist in managing the proliferation of weeds throughout the construction site. Opportunities to integrate the Weed Management Strategy with current and future undertakings by PCL in the Cotter Catchment will be investigated. The weed management strategy will be included in the Landscape Rehabilitation Management Plan for consideration by the Environment Protection Authority prior to construction work commencing. The construction of the Enlargement of the Cotter Dam will temporarily disturb land at the main construction site (see drawing GHD-ECD-DAM-GN-SKT-1002). A portion of this area is located within the future ECD inundation area and will therefore be disturbed permanently. The clay borrow areas (if used) will disturb land that will ultimately be inundated and thus permanently disturbed. The construction site and clay borrow areas have been chosen at locations that will in the future be permanently or partially inundated and in doing this the temporary land disturbance impacts have been minimised. All soil erosion, and weed management matters will be addressed through the provisions of the CEMP (a draft CEMP is included with this submission). It is anticipated that the management and mitigations will be set out in an agreed CEMP with the land manager and relevant officers of PCL and approved by the EPA. Minor land disturbance will occur along the edges of forestry roads and access tracks that will be upgraded. The disturbance will be minimised and appropriate sediment and erosion control measures installed to protect the catchment and reservoir from sedimentitious run-off. Roads will be upgraded and permanent erosion measures installed to ensure that impacts are mitigated during and after the construction period. ENLARGEMENT OF THE COTTER DAM AND ASSOCIATED WORKS DEVELOPMENT APPLICATION - IMPACT TRACK ASSESSMENT 43