Report to COUNCIL for decision

Transcription

1 Title: Section: Prepared by: Waipaoa Flood Control Scheme Resilience Project Update Environmental & Regulatory Services Neil Daykin (Rivers, Drainage and Coastal Manager) Meeting Date: 1 December 2016 Legal Financial Significance = Medium Report to COUNCIL for decision SUMMARY In the 2015 Long Term Plan, Gisborne District Council committed to the Waipaoa Flood Control Scheme Resilience Upgrade - a long term project (15 years) to improve the resilience and level of protection offered by the scheme from as low as a 70 year return period with limited freeboard and no climate change factors of safety to a 100 year return period including m of freeboard and 2090 climate change factors of safety. Council identified this as their number one project at a risk workshop (Appendix 1). The resilience upgrade will provide certainty and security to the community, and to land development and agricultural activities on the Poverty Bay Flats. During the planning phase Councillors expressed concerns over the timeframe to achieve full protection. In addition, Hawke s Bay Regional Council (HBRC) identified a number of major risks from the initially proposed 15 year project duration and have therefore investigated possibilities to complete this project within 8-10 years. For example, the risk of an event occurring before the upgrade is completed. We have summarised the pros and cons for each option in Appendix 2 and preliminary costs in Appendix 3. We are seeking approval from council to: 1. Consider the financial and significance implications for moving the project duration from 15 years to 10 years with associated realignment of budgets. 2. Pursue land acquisition strategy Option D 3. Realign budgets to undertake land acquisition strategy Option D predominantly upfront in years 2-3 (2016/17 and 2017/18). 4. Apply for a single resource consent for the full extent of the proposed works and including the cycle paths. The decisions or matters in this report are considered to be of Medium significance in accordance with the Council s Significance and Engagement Policy. A Page 1 of 30

2 RECOMMENDATIONS That the Council: 1. Notes the contents of this report. 2. Considers the financial and significance implications for moving the project duration from 15 years to 10 years with associated realignment of budgets. A 10 year duration means there are eight years remaining and the project will be completed by Adopts land acquisition strategy Option D which is to acquire all land over the eastern stopbanks and use predominantly statutory rights under the Act for the western stopbanks except in strategic locations (approx. 48% purchase, 2% easements and 50% statutory rights), 4. Realigns budgets to undertake land acquisition strategy Option D predominantly upfront in years 2-3 (2016/17 and 2017/18). 5. Applies for a single Resource Consent for the full scheme upgrade and including cycle paths. Authorised by: Neil Daykin Rivers, Drainage & Coastal Manager Kevin Strongman Group Manager Environmental & Regulatory Services Keywords: Waipaoa flood control project, resilience project. A Page 2 of 30

3 BACKGROUND 1. The Waipaoa River Flood Control Scheme (WFCS) began more than 60 years ago to provide flood protection to the productive Poverty Bay floodplains and Gisborne City following heavy flooding in a 1948 storm. The Scheme thus has a dual urban and rural flood protection function. WFCS consists of some 63km of stopbanks, 638ha of floodway (land between the river & stopbank), bank protection works and culverted outlets along the Waipaoa River. 2. The scheme was substantially completed by During the Cyclone Bola flood of 1988 the stopbanks were overtopped in a number of locations, with minor repair and upgrade works carried out thereafter. Periodic reviews of the Scheme have occurred since Bola (1993, 1995, 2009 & 2012). 3. In the 2015 Long Term Plan, Gisborne District Council committed to the $15,900,000 WFCS upgrade resilience project. The outcome of the 15 year project is to improve the level of protection and resilience offered by the scheme. The upgrade project will also provide certainty and security to the community at a time when land flood events are expected to increase in frequency. 4. The project will provide a consistent level of protection, confidently to 100 year return period river levels based on the expected future climate of 2090 including m of freeboard. 5. Climate change for 2090 results in a predicted approximately 25% increase in peak discharge/flows. Freeboard is a factor of safety usually expressed in meters (or the like) above a flood level for purposes of floodplain management. "Freeboard" tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, bridge openings, and the hydrological effect of urbanization of the watershed. 6. The first two years of the 15 year project were allocated for planning, consenting, land purchase and communication engagement. The project team were asked by Council to investigate a shorter delivery timeframe and on investigating, identified the possibility of completing the project earlier than 15 years. This along with developing a land acquisition strategy and resource consent submission were tabled as the next steps for the project at the Future Tairawhiti meeting on 21 July On completion of the WFCS resilience upgrade, all reaches (sections) will have the same level of flood protection. There is no allowance for deliberate spilling of floodwaters, i.e. there are no low points along the stopbank to preferentially flood a specific area and thus alleviate flooding elsewhere. 8. It is important to note that the design of the scheme is based on the design flow being constant down the length of the scheme. This is a standard and acceptable practice for such a river reach. Therefore, with a single design flow/event, you cannot design the stopbanks to overtop evenly. Should such an event occur, this overtopping naturally starts in the upper reaches (top of the scheme). This reduces the likelihood of overtopping further downstream but doesn t prohibit it. A Page 3 of 30

4 DISCUSSION AND OPTIONS: Consider the financial and significance implications for moving the project duration from 15 years to 10 years with associated realignment of budgets. A 10yr duration means there are 8 years remaining and the project will be completed by Consideration of the financial and significance implications of realigning project budgets and timings needs to be undertaken holistically with Council s other major projects to better manage expectations and competing requirements. 10. Staff have investigated, analysed and compared three timeframe options as follows: 8 years (6 years remaining) 10 years (8 years remaining) 15 years (original proposal) (13 years remaining) 11. The pros and cons for these options are summarised in Appendix 2 and the costs in Appendix 3. For each option, years 1 & 2 were allocated for planning and obtaining the necessary consents. We are currently in year 2 for any of the options. 12. The original programme and budget allocation was for 15 years but during the planning phase and risk workshops, a number of major risks were identified as detailed below: - Complacency or slow start due to long duration. - A major flood occurs before project completion i.e. the quicker the project is completed the sooner the full protection level of service is achieved. - Length of stopbank under construction or newly constructed and the associated failure/flood risks during the six month construction season. - Delayed social, environmental and economic benefits due to long project duration. - A loss/change of key team members and skills due to project duration. - A failure to deliver project (or parts) due to the long duration and delays. - Availability of plant and resources to undertake project management, construction supervision and the construction works themselves. - Health and Safety (H&S). - Project timeframes versus costs and risks - Increasing costs over time 13. The construction methodology requires removal of the grass which is an integral component of any stopbank. Without this grass protection, the exposed earth stopbank has a much higher failure risk during a flood event. Thus the more stopbank you have under construction each year the higher the stopbank failure risk and the higher the consequences to life and property during a flood. There are reduced flood risks from completing the upgrade more quickly (as the community would gain the higher design level of service protection on completion), however these need to be balanced against the flood risks during construction. 14. A duration less than 8 years (i.e. 6 years remaining) for land acquisition and construction was deemed unachievable for cost, resources and risk purposes and thus not investigated further. Given the marginal achievability and the risk with the 8 year (i.e. 6 years remaining) duration, the 9 year (i.e. 7 years remaining) duration was not investigated further. A Page 4 of 30

5 15. Each of the three options carry some level of the above risks but we have identified and concluded that the 8 year option carries the highest risk due to amount of stopbank that would be under construction each year (10km average) during the 6 month construction season and the associated increase in stopbank failure risks. This would also be challenging for contractors to complete and may also lead to increased H&S risks. We have concluded that the availability of local plant/resources and the risks/liabilities on the contractors will result in much higher costs for the 8 year option (estimated $18.5m versus $15.9m for 10 or 15 year options). 16. We therefore, do not recommend the 8 year option as feasible and effective for council due to the high risks mentioned above and in Appendix From a cost perspective (Appendix 3), there are likely to be some marginal cost savings going from a 15 to 10 year project duration due to lower establishment costs, scale of contracts and availability of local plant and resources. We recognise the possibility of some higher unit rates due to contractors factoring in the higher risks/liabilities with the shorter duration. Thus we have estimated based on available data that both 10 and 15 year options are approximately $15.9m. 18. We recommend the 10 year option (8 years remaining) as being the most suitable and achievable whilst balancing the risks, costs and timing of benefits. This construction length will still be challenging but achievable whilst maximising the opportunities for local contractors. 19. Construction Programme: This upgrade project focusses on providing a consistent level of protection and increasing the resilience of the assets for a 100yr return period event rather than an upgrade to a significantly higher return period event. The preliminary construction programme has been prepared based on the analysis of the areas of benefit (greatest social, economic & environmental value), achieving full protection benefits as soon as feasible and the current asset condition and risks. 20. Therefore, construction will start with the eastern side followed by the western side, with priority given to those sections with the highest asset risk scores. Full protection to the eastern side will be achieved in approximately 5-6 years time and the western side in 6-10 years time. A preliminary construction order of priority is shown below in Figure 1. A Page 5 of 30

6 Figure 1: Preliminary construction order of priority A Page 6 of 30

7 DISCUSSION AND OPTIONS: Adopt land acquisition strategy Option D which is to acquire all land over the eastern stopbanks and use predominantly statutory rights under the Act for the western stopbanks except in strategic locations (approx. 48% purchase, 2% easements & 50% statutory rights) and rearrange the programme to undertake these predominantly upfront in years 2-3 (2016/17 and 2017/18) 20. The WFCS is constructed on a mixture of land tenure including land owned by Council, the Crown and private landowners including owners of Maori Land. The scheme is protected (by statutory rights) under the Soil Conservation and River Control Act 1941 (the Act). 21. For the resilience upgrade project, land acquisition or an interest in land at least, will need to be acquired in places. The Property Group (TPG) have undertaken an acquisition strategy for the project and proposed four options (A to D) as follows: Option A: Option B: Option C: Option D: Acquire all land over entire footprint of stopbank not already in Council ownership. Equates to 100% land ownership. Acquire predominantly Easements not already in Council ownership. Equates to approx. 18% purchase, 44% easements & 38% statutory rights. Minor land purchase and rely on statutory rights under the Act. Equates to approx. 18% purchase, 2% easements & 80% statutory rights. Acquire all land over eastern stopbanks and use predominantly statutory rights under the Act except for strategic locations for the western stopbanks (This level of land purchase was priced for in the original budgeting for the LTP). Equates to approx. 48% purchase, 2% easements & 50% statutory rights. 22. TPG have staged the land acquisitions to occur in the most part prior to construction as this allows us to prioritise the program based on maximising benefit and reducing risk rather than a program based on ease of access. This will also provide surety for access and construction prior to any works or significant cost outlays. This staging will significantly reduce the risk to the project of any land owners holding out or trying to leverage Council towards the end of the project. Refer to Appendix 4 for full strategy report from TPG. 23. The cost estimates for the four options are detailed below (Table 1). Table 1: Land Acquisition Cost Estimates Financial Year Option A ($) Option B ($) Option C ($) Option D ($) 2016/17 $1,234,500 $1,076,500 $690,500 $690, /18 $2,913,000 $1,582,000 $235,000 $1,118,000 TOTAL $4,147,500 $2,658,500 $925,500 $1,808, The pros and cons for each option are detailed in Table 2. When appropriately balancing the risks, cost and security of owning land that the stopbanks are constructed on, we recommend Land Acquisition Option D. In addition, this level of land purchase was priced for in the original budgeting for the LTP and is aligned with our existing ownership model with appropriate improvements to minimise risks. A Page 7 of 30

8 Table 2: Comparison of pros and cons for Land Acquisition options Land Acquisition Strategy Pros Cons Purchase Easements Statutory (%) (%) Rights (%) Option A Acquire all land over entire footprint of stopbank not already in Council ownership. Equates to 100% land ownership Provides greatest security to assets as we would own all land Greatest certainty and security over assets/scheme Highest cost Highest risk in respect of acquisition due to complex land status, ownership and/or property type Lowest risk of operational/management issues Highest risk of non-completion or delays Option B Acquire predominantly Easements not already in Council ownership. Equates to approx. 18% purchase, 44% easements & 38% statutory rights Lowest amount of land purchase Moderate risk of non-completion or delays High cost for mostly just easements and some statutory rights compensation Lowest increase in GDC land ownership Lowest increase in land under full GDC control High risk of operational/management issues Moderate risk to integrity of assets Option C Minor land purchase and rely on statutory rights under the Act. Equates to approx. 18% purchase, 2% easements & 80% statutory rights Cheapest Lowest risk of non-completion or delays Lowest certainty and security over assets/scheme Highest risk to integrity of assets Highest risk of operational/management issues Lowest increase in GDC land ownership Lowest increase in land under full GDC control Acquire all land over eastern Option D stopbanks and use predominantly statutory rights under the Act except for strategic locations for the western stopbanks (This level of land purchase was priced for in Highest certainty and security over assets/scheme for eastern side of stopbanks Moderate certainty and security over assets/scheme for western side of stopbanks Moderate risk of non-completion or delays Relies on statutory rights for western side the original budgeting for the LTP). Equates to approx. 48% purchase, 2% easements & 50% statutory rights Moderate risk of operational/management issues Low risk in respect of acquisition as eastern side has fewer properties and significantly less complex land status, ownership and/or property type than the western side A Page 8 of 30

9 DISCUSSION AND OPTIONS: Applies for a single resource consent for the full extent of the proposed works and including cycle paths 25. Table 3 below summarises the pros and cons of the three resource consent options we have considered. Applying for and gaining a single resource consent will provide certainty that the whole project can be undertaken and completed whilst maximising efficiency in regards to application, public consultation and processing costs. In addition, project risks are reduced as it removes any risk of the project being delayed or stopped part way through construction. 26. Including the cycle path in the upgrade resource consent also maximises efficiency in regards to application, public consultation and processing costs but allows a more holistic and strategic approach to the use and development of the flood defence assets of the WFCS. Table 3: Comparison of pros and cons for Resource Consent options Options Pro s Cons Staged Consent Discrete number of landowners requiring consultation Can deal with environmental effects in smaller bites Costs spread Risk of consent not being obtained for all of scheme Potential timing and budgeting issues if any single consent is delayed Least cost effective Single Consent Certainty for whole of upgrade project Community engagement across whole of upgrade project Cost effective A bigger job More upfront cost Potential timing and budgeting issues if consent is delayed Single consent with cycleway Community engagement across whole of both projects Additional community (recreation) benefit One notified overarching consent process Most cost effective May be adjacent land owner opposition No existing integrated cycle plan at this stage May delay/distract from consenting for upgrade We therefore, recommend that Council approves applying for a single resource consent covering the full extent of the works including cycle paths. A Page 9 of 30

10 ASSESSMENT OF SIGNIFICANCE Criteria This Report The Process Overall The effects on all or a large part of the Gisborne district Medium Medium The effects on individuals or specific communities Medium Medium The level or history of public interest in the matter or issue Medium Medium Inconsistency with Council s current strategy and policy Low Low Impacts on Council s delivery of its Financial Strategy and Long Term Plan. Medium Medium The decisions or matters in this report are considered to be of medium significance in accordance with Council s Significance and Engagement Policy because: There are no changes proposed to the level of funding, just to the timeframe and spread/alignment of costs. In the 2015 Long Term Plan, Gisborne District Council committed to the Waipaoa Flood Control Scheme Resilience Upgrade. Council identified this as their number one project at a risk workshop. The community have been involved through the Long Term Plan process. The proposed land acquisition strategy balances Council s risk with effects on individuals or specific communities. COMMUNITY ENGAGEMENT 1. The community have been involved through the Long Term Plan process. 2. Ongoing community engagement will occur throughout the duration of this project including but not limited to the resource consent process. 3. The Property Group have been engaged to manage the communication plan. CONSIDERATIONS Financial/Budget 4. Budgets have been discussed earlier in the report. 5. There is funding set aside in the LTP for the first 10 years of the original 15 year project duration. 6. Shortening the project duration to 10 years and undertaking land acquisition at the start will require budgets to be brought forward. Legal 7. There are no legal implications relating to this work at this stage. POLICY AND PLANNING IMPLICATIONS 8. The implementation of the strategy is consistent with Council policy and plans in this area. A Page 10 of 30

11 RISKS 9. Risks have been discussed earlier in the report but include: Construction Project duration Land acquisition Consent process Adverse effect on the community from not proceeding Publicity / public perception Health and Safety Financial / security of funding Political NEXT STEPS Date Action/Milestone Comments Early 2017 Lodge Resource Consent We expect a decision by May-June 2017 Early 2017 Start land acquisition Completion expected by mid-2018 Early-mid 2017 Start lessee discussions 2016/17 Finalise designs Mid 2017 Prepare tender documents for 17/18 construction season A Page 11 of 30

12 APPENDICES Appendix 1: Council Project Priority Ranking Appendix 2: Comparison of pros and cons for 8, 10 & 15 year project durations Appendix 3: Cost comparison for 8, 10 & 15 year project durations (note we are currently in year 2) Appendix 4: Land Acquisition Strategy & memorandum A Page 12 of 30

13 Appendix 1: Council Project Priority Ranking A Page 13 of 30

14 Appendix 2: Comparison of pros and cons for 8, 10 & 15 year project durations Option Km/year Pros (For) Cons (Against) 8 Years 10km - Scale of earthworks. - Opportunities for many local contractors - Lowest (relative) establishment cost - Shortest public disruption - Opportunities for large out of district contractors - Most intense public disruption - Local contractors might not have enough plant to undertake works. - Stretched local contractors could impact quality. - Could cause over supply of plant during winter shut down. - Longest length of new non-grassed stopbank exposed to flooding (takes time for grass establishment) - Highest risk of flooding from failure of new stopbanks. - Size of earthworks each year compared to size of local contactors would likely increase prices as contractor factors in risks of non-completion. - Highest number of multiple sites open at any one time. - Hardest to monitor Health and Safety wise. - Highest staff construction supervision costs - Changes to the funding programme allocation in years 3-8 needed. 10 Years 8km - Lowest overall project costs. - Scale of earthworks - Changes to the funding programme allocation in years 3-10 needed. - Higher establishment and disestablishment cost - Opportunities for many local contractors - Medium (relative) establishment costs - Manageable length without the need to open more sites and to establish excess of plant/ - Less tender cost - Good opportunity for local contractors to form joint ventures over a good term length - Less potential on staff changes and earlier project completion and achievement of flood protection. - Medium intensity and medium duration public disruption 15 Years 4-5km - Easiest manageable contracts and Health and Safety - No need for changing funding programme allocation - Lowest intensity public disruption - Highest cost for establishment and disestablishment - Longest duration disruption to public, land owners & lessees - Loss of funding - Loss of skills and staff turnaround. - Larger overall cost for construction and contract admin - Highest risk of flooding from overtopping of stopbanks A Page 14 of 30

15 Appendix 3: Cost comparison for 8, 10 & 15 year project durations (note we are currently in year 2) Year Financial Year LTP Budget 15 Year Activity Programme 15 Year Budget Stopbank Constructed (km) 10 Year Activity Programme 10 Year Budget Stopbank Constructed (km) 8 Year Activity Programme 8 Year Budget 1 15/16 $250,000 Overall cost $130,000 0 Overall cost $130,000 0 Overall cost $130,000 0 Project Management $50,000 Project Management $50,000 Project Management $50,000 Land Purchase $400,000 Land Purchase $690,500 Land Purchase $690, /17 $500,000 Consenting $60,000 Consenting $60,000 Consenting $60, Design $30,000 Design $30,000 Design $30,000 0 Other (soil sample, site investigation) $80,000 Other (soil sample, site investigation) $80,000 Other (soil sample, site investigation) $80,000 $620,000 $910,500 $910,500 Project Management $50,000 Project Management $60,000 Project Management $80,000 Construction $400,000 Construction $400,000 Land Purchase $1,118, /18 $800,000 Land Purchase $300,000 Land Purchase $1,118,000 Design $100, Design $30,000 Design $30,000 Construction $1,500,000 8 Other $50,000 Other $50,000 Other $50, /19 $800, /20 $1,000, /21 $1,000, /22 $1,000, /23 $1,200, /24 1,400,000 $830,000 $1,658,000 $2,848,000 Project Management $50,000 Project Management $70,000 Project Management $100,000 Land Purchase $300,000 Construction $1,650,000 Professional Services $150,000 Construction $450,000 2 Design $100,000 8 Construction $2,300,000 Design $40,000 $840,000 $1,820,000 $2,550,000 Project Management $30,000 Project Management $60,000 Project Management $100,000 Land Purchase $300,000 Construction $1,650,000 Construction $2,300,000 8 Construction $600,000 3 Professional Services $100,000 Professional Services $150,000 Professional Services $30,000 $960,000 $1,810,000 $2,550,000 Project Management $20,000 Project Management $50,000 8 Project Management $900,000 Land Purchase $300,000 Professional Services $100,000 Professional Services $150,000 Professional Services $30,000 4 Construction $1,700,000 Construction $2,300,000 Construction $650,000 $1,000,000 $1,850,000 $3,350,000 Project Management $30,000 Project Management $50,000 Project Management $100,000 Professional Services $60,000 Professional Services $90,000 Professional Services $150, Construction $900,000 Construction $1,700,000 Construction $2,800,000 $990,000 $1,840,000 $3,050,000 Project Management $30,000 Project Management $60,000 Project Management $100,000 Professional Services $70,000 Professional Services $100,000 Professional Services $150, Construction $1,100,000 Construction $1,800,000 Construction $2,800,000 $1,200,000 $1,960,000 $3,050,000 Project Management $20,000 Project Management $70,000 Professional Services $80,000 Professional Services $130, Construction $1,300,000 Construction $1,800,000 $1,400,000 $2,000,000 Project Management $20,000 Project Management $70, /25 1,400,000 Professional Services $80,000 Professional Services $130, Construction $1,300,000 Construction $1,800,000 $1,400,000 $2,000, /26 $1,318,329 $1,318, km s 12 26/27 $1,318,329 $1,318, /28 $1,318,329 $1,318, /29 $1,318,329 $1,318, /30 $1,318,329 $1,318,329 4 TOTALS $15,941,645 $15,961,645 $15,978,500 $18,438,500 Stopbank Constructed (km) A Page 15 of 30

16 Appendix 4: Land Acquisition Strategy & memorandum A Page 16 of 30

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