Report to FUTURE TAIRAWHITI Committee for decision

Transcription

1 Title: Locales Tairāwhiti Observatory Concept 2017 Section: Prepared by: Liveable Communities Andrew White (Director Liveable Communities) Meeting Date: 20 July 2017 Legal Financial Significance = low Report to FUTURE TAIRAWHITI Committee for decision SUMMARY The purpose of this report is to seek the Future Tairāwhiti Committee s endorsement of the Observatory rebuild concept, in order for staff to proceed with detailed design work and to develop accurate cost estimates for consideration by Council in its Long Term Plan deliberations. The Titirangi Observatory building has been closed to public use since 2015, following completion of seismic assessment reports by GDC Consultants (Structural Engineers) of Napier, which recommended that the building should be closed as they did not consider it safe to be used for its intended purpose. On 16 November 2016, the Community & Recreation Manager presented a report to the Community Development & Services Committee recommending that the Council should undertake community consultation through the 2017/18 Annual Plan, in order to determine the community s preferred option for the future of the building. Through the annual plan consultation process, the community was asked what it thought of the observatory and how it should be used in the future. Feedback was received from 71 submitters, with 67 submitters saying they wanted Council to keep an observatory on Titirangi and that they would like to see it redeveloped. Four submitters said they were against redeveloping the Observatory. On 18 May 2017, staff advised Council that high level designs would be prepared for Council s consideration. Consequently, Locales Ltd was engaged to prepare an interpretation strategy and observatory concept including high level implementation costs. Along with an architectural concept already prepared by Kingsbeer Architecture, the Locales material provides Council with a comprehensive concept to consider. Locales Ltd will attend the meeting to present its work to the Committee. o The decisions or matters in this report are considered to be of low significance in accordance with the Council s Significance and Engagement Policy. Page 1 of 7

2 RECOMMENDATIONS That the Future Tairawhiti Committee: 1. Notes the contents of this report. 2. Approves the observatory rebuild concept, which includes: (a) (b) (c) (d) (e) (f) demolition and construction of a new observatory building, development of a Titirangi Stories package, establishment of a Tairāwhiti Night Experience for users of the observatory, construction of a Star Compass, installation of a set of sculptural installations (a Star Park ), and development of a Digital Night Guide. 3. Instructs the Chief Executive to develop detailed designs and accurate costings for the Observatory rebuild for consideration in Council s Long Term Plan. Authorised by: Andrew White Director Liveable Communities Keywords: Observatory, Titirangi, observatory concept, Ngati Oneone Page 2 of 7

3 BACKGROUND Land and Building Description 1. A Memorandum of Transfer was signed on 15 December 1967 between Council, Nelsons (NZ) Limited and Gisborne Sheep Farmers Freezing Co Limited for management of land including the site of the existing observatory building. Two clauses in this Memorandum are particularly relevant to the observatory building and activity: a. II.I The council will not sell lease or part with possession of the said lands or any part thereof except to grant temporary licences to graze sheep and lambs thereon and the council hereby undertakes to apply the net revenue received from such licences towards the upkeep of the said lands as pleasure grounds and gardens b. II.3 The council will not erect or permit on the said lands or any part thereof the erection of any buildings except only the erection on that portion of the said lands more than three quarters of the way to the highest point thereof above sea-level of hot-houses, green-houses and/ or refreshment kiosk and/or an observatory. No intoxicating liquor to be kept supplied or sold in any such kiosk or elsewhere on the said lands. 2. The James Cook Observatory was built to celebrate Cook s association with astronomy. The observatory is a retrofit of a previously existing concrete bunker located behind a gun emplacement. The original northern part of the building was constructed during World War II to be used as a Home Guard post. An extension was added to the original building to establish the James Cook Observatory building, which was opened in The building is a single storey structure, constructed using masonry block walls with a concrete ground slab. The roof comprises a reinforced concrete deck on the original part of the building, and lightweight timber framing on the newer part. The astronomy dome is constructed on top of the timber-framed roof section. The building foundations comprise shallow continuous reinforced concrete strip footings, which are not integrally connected to the concrete ground slab. 4. Council granted a formal licence to the Gisborne Astronomical Society (GAS) to occupy the observatory building in A licence is usually a short-term right to occupy a property for a particular purpose and, unlike a lease, it does not provide a right to exclusive occupation and grants no interest in the land (hence is considered to not be in breach of clause II.1 of the Memorandum [provided in paragraph 1 above]). The original licence term was for a period of five years. Until 2015, it was renewed for further five year terms on four occasions. In 2015, due to structural concerns about the building, and after expiry of the latest licence term, the observatory was closed for use. Building Structure 5. In 2015, a structural engineer (GDC Consultants Napier) was engaged to undertake an Initial Seismic Assessment (ISA) of the observatory building. An ISA is a desktop exercise to assess the design drawings and other available information. The ISA report, completed in May 2015, indicated the observatory building had an overall score of 20% New Building Standard (NBS) for an IL2 (importance level 2) building, corresponding to a Grade D building and classified as Potential Earthquake prone building. Based on this initial assessment, staff decided to close the observatory to the public, as it was deemed unsafe for operation. Page 3 of 7

4 6. Staff then initiated a Detailed Seismic Assessment (DSA) to determine the building s current level of seismic risk and to provide recommendations for improvement if required. The DSA report was completed in September 2015 and gave a rating of 39% NBS for an IL2 building for the overall building. The report classified the building as a moderate risk, which is higher than the high-risk category of 33% NBS, but below the recommended low-to-medium risk category of 67% NBS. 7. The engineer indicated that they did not consider the building safe to be used for its intended purpose, and consequently the observatory building has remained closed (although Council is not legally required to close a medium risk building). 8. The engineer provided a rough order cost of $141,000 to strengthen the building to a lowto-medium (67% new building) standard. This cost would require refinement through detailed design and tender processes if it was Council s preferred option. Figure 1: Building risk classifications Building Grade Percentage of New Building Strength (%NBS) Approx. Risk Relative to New Building Life-safety Risk Description A+ >100 <1 Low Risk A 80 to to 2 times Low Risk B 67 to 79 2 to 5 times Low or Medium Risk C 34 to 66 5 to 10 times Medium Risk D 20 to to 25 times High Risk E <20 More than 25 times Very High Risk Annual Plan Consultation 9. In November 2016, an issues and options report was discussed at the Community Development & Services Committee. The Committee resolved to keep the James Cook Observatory closed and undertake further consultation through the 2017/18 Annual Plan to determine the community s preferred option. The observatory remains closed and will do so until a decision is made around the options available. 10. Consultation through the Annual Plan process resulted in overwhelming support for keeping and redeveloping an observatory on Titirangi. Geotechnical Issues 11. In 2017, Land Development & Exploration (LDE) undertook a geotechnical investigation of the site occupied by the James Cook Observatory on the summit of Titirangi. The purpose of this investigation was to characterise the engineering geology of the site, determine if existing damage with the observatory is related to land movement, determine the future ground deformation, and to provide geotechnical recommendations for the stabilisation of the site. 12. The in-depth geotechnical investigation of the site confirms the majority of the building (southern three-quarters opened in 1971) has been built over various thicknesses of nonengineered fill, in turn overlying Mangatuna Formation geology, some of which is prone to creep instability and land slippage. The fill was generally not encountered under the northern smaller portion of the building constructed in Page 4 of 7

5 13. The newer 1971 part of the building has subsided (rotated) down towards the south, and to the west (inland towards Kaiti). The southern reaches of the 1971 building, adjacent steps and end of a retaining wall have also moved laterally towards the south. No evidence of rotation or land slippage under the 1942/43 building was encountered. 14. It is the professional opinion of LDE that the main reasons for the building distortion are consolidation settlement of the non-engineered fill and land slippage. 15. Continuation of the consolidation settlement and land slippage is considered likely should no stabilisation measures be undertaken. Shallow-seated land slippage towards the building from cut slopes below the building to the south and east (installed in 1942 and 2015) is considered likely to continue should no stabilisation measures be undertaken. Observatory Building Design 16. Kingsbeer Architecture has prepared an architectural concept for a new observatory building at the Titirangi summit. This concept was reported to the Community Development & Services Committee (Report ) in November The concept, with a rough order estimate to build of $480,000 (excluding compliance costs) is provided as Appendix 1 to this report. Tairāwhiti Observatory Concept 18. Locales Ltd has prepared a concept for a Tairāwhiti Observatory on Titirangi. The concept provides Council with a number of options for consideration. The options are largely designed to give Council solutions if it decides to retain the existing observatory building, build a new observatory building, or not have an observatory building. The Locales work excludes any architectural drawings for the observatory building, on the basis that architectural concepts have already been prepared by Kingsbeer. Locales proposes a number of interpretive and physical developments to create a user experience in and around the observatory, based on four experiential principles: create a sense of wonder through what is visible in the day/night sky from Titirangi focus on Tairāwhiti accounts of cosmology, constellations and seasonal observations provide experiences that work during the day and night create sturdy, safe but playable interactions. 19. High level cost estimates to implement the Locales work range from $1.57M to $2.915M depending on the options selected. These costs would be refined through detailed design. 20. The concept is provided as Appendix 2 to this report. 21. Locales will attend the meeting to present its proposals to the Committee. DISCUSSION AND OPTIONS 22. Given the community s view that there should be an observatory on Titirangi and that it should be redeveloped to provide for users, Council is now in a position to consider whether it wishes to retain and redevelop the existing observatory building, or demolish the building and construct a new observatory at the Titirangi summit. 23. Should the building not be demolished and rebuilt, a palisade wall (rows of closely spaced piles) foundation system is recommend to be installed under the east, south and west facing walls of the 1971 part of the observatory to arrest the building movement. LDE recommends that a Charted Professional Engineer with experience in the structural design of palisade walls design these if that is the route Council decides to take. There has been no cost to date for this option nor has the option of renovating the existing building been explored. Page 5 of 7

6 24. If demolition and rebuilding of the observatory is Council s preferred option, LDE recommends that a deep perimeter strip engineered foundation is installed below the unengineered fill to ensure there is stability for the new build. It is recommended the unengineered fill is removed and replaced with the proper amount of engineered fill. 25. Locales will present its view at the meeting that a new observatory building or a clean site is preferable to a renovated observatory building for optimising visitor experience, particularly in respect to establishing a Star Compass on the observatory site. Options Assessment Option Dimension 1: Observatory Building Positives Negatives Option 1: Undertake detailed design work to retain and renovate the existing observatory building Probably lower cost solution than building a new observatory - however the cost of redeveloping the building has not been estimated. Would support the community expectation that an observatory is provided on Titirangi. The building is not currently fit for purpose and would require significant renovation a fit for purpose outcome may be difficult to achieve. Locales advice is that the existing building is not a particularly feasible option for establishing a Star Compass. Option 2 (Preferred Option): Undertake detailed design work to demolish and build a new observatory building A fit for purpose building would be designed and accurate cost estimates prepared. Would support the community expectation that an observatory is provided on Titirangi. Would support the outcome of providing an ideal blank canvas for establishing the Star Compass as proposed by Locales. Probably the highest cost option Option 3: Demolish and do not replace the observatory building Probably the lowest cost option Would provide an ideal blank canvas for establishing the Star Compass as proposed by Locales. Would not meet the community expectation that an observatory is provided on Titirangi Would mean that some elements of Locales proposal would not be able to be implemented, lessening the visitor experience potential. Option Dimension 2: Locales Proposal Option 4 (Preferred Option): Undertake detailed design and develop accurate cost estimates to implement the Locales Proposal The Locales proposal provides a visitor experience well beyond what has been previously provided by the observatory. If implemented, the proposal will transform the Titirangi summit into a truly experiential and interactive community and visitor setting. The rough order cost of implementing the proposal is in the range of $1.57M to $2.915M. Option 5: Do not proceed with further investigation into the Locales Proposal This is a low cost option The opportunity for added value visitor experience beyond what has previously been provided is not taken. Page 6 of 7

7 ASSESSMENT OF SIGNIFICANCE Criteria This Report The Process Overall The effects on all or a large part of the Gisborne district Low Medium The effects on individuals or specific communities Low High 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. Low High 26. This report is part of a process to arrive at a decision that will/may be of medium level in accordance with the Council s Significance and Engagement Policy COMMUNITY ENGAGEMENT 27. The Community was asked for its views on the observatory through the 2017/18 Annual Plan process. A large majority of respondents indicated they wanted an observatory to remain on Titirangi. 28. Ngati Oneone, as Council s co-management partner in respect to Titirangi decision making, has had input into the Locales concept development work and is generally happy with the approach being taken, subject to ongoing decision making involvement in the recommended detailed design process. 29. The Gisborne Astronomical Society has been involved in the concept development work described in this report. 30. It is proposed that, if approved, the detailed design work to be undertaken will inform Council s Long Term Plan community consultation process. CONSIDERATIONS Financial/Budget 1. Funding for redevelopment of the Observatory has not been contemplated in Council s Long Term Plan. It is proposed that Council will consult on detailed design and costings through its Long Term Plan process, and will seek support from local and national funders to assist with the redevelopment. Legal 2. There are no legal implications with this report. NEXT STEPS Date Action/Milestone Comments 14 December 2017 Detailed design and costings reported to Council APPENDICES Appendix 1: Kingsbeer Architecture building design concept Appendix 2: Locales Ltd Tairāwhiti Observatory concept Page 7 of 7