Official Information Request - Tarawera Sewerage Reticulation Scheme

Sent: Friday, 7 October 2022 11:33 am
Subject: Local Government Official Information and Meetings Act request - Tarawera Sewerage Reticulation Scheme funding

I refer to request of 21 September 2022 under the Local Government Official Information and Meetings Act regarding the $1.5M amount, as set out in the letter to residents of 1 July 2022, paid towards costing the Lake Tarawera sewerage reticulation scheme.

You have requested advice on the purpose and nature of this $1.5M scheme design cost element. The $1.5M is for the design component of the project and represents a 4.5-6.5% fee on the project’s total gross cost of between $23-$32M.

At a high level the fee paid requires the delivery of site investigation, assessment, options exploration and appropriate documentation to cover the following items and categories of design:

-Development of a Basis of Design Report. Sets out the key parameters and assumptions to be used in the design work. Outlines the design and performance requirements for the Tarawera Wastewater Reticulation Scheme design. It includes additional design and performance requirements that require Council approval. Submitted to RLC for review and steering input.

-Trunk Main Concept Design:

• Topographical mapping of the proposed trunk main route
• Analysis of different trunk main route options for connection to the existing reticulation to WWTP
• Hydraulic modelling of the trunk main to identify options for equipment sizing, location and performance
• Geotechnical investigations along proposed route and identified pump stations
• Review of HAIL and heritage records that may be affected by the proposed works
• Development of several Preliminary Design options and post-review iterations to address hydraulic performance requirements of the scheme
• Specification of trunk main pipe ratings, sizes and lengths
• Specification of pump station locations, layouts, equipment, power supplies, control schemes, maintenance requirements
• Specification of scheme control valves, air inlet valves, scour valves, flush points, chambers, culvert crossings etc.
• Investigation into consenting requirements for construction.
• Water hammer analysis of proposed concept scheme.
• Septicity study into proposed concept scheme.
• Design review meetings with client and follow-up design work.
• Preparation of drawing set for key equipment locations and pipe routing within roadway.
• Preparation of P&ID drawings of scheme.
• Conduction of HAZOP study and subsequent design adjustments to improve operability.
• Submission of final concept design to client: Drawings, specifications, bills of materials etc.
• Subsequent optimisation of concept design and value engineering.
• Liaison with utilities companies for pump station supply requirements.

-On-Property Design

• Organising / management of visits to all properties (developed about 450 plus potential lots 100)
• Assembly of all relevant records for each property (including nature and location of existing waste water systems and low-points within the section)
• Preparation of individual property-specific documentation packs for initial design and assessment
• Communications to all properties describing intended work and requesting appointments to visit
• Management of database for property visits undertaken, correspondence exchanges etc.
• Subsequent follow up correspondence to arrange visits to non-response properties (letters, ‘sorry we missed you” calling cards etc.
• Health and safety planning for visits (including undertaking specific training on dog safety)
• Undertaking physical property visits to confirm existing systems, review any special installation requirements.
• Discussions with land owners to agree preferences for installation and reinstatement requirements
• Undertaking surveys and testing (where needed) of property electrical supplies
• Updating Layout Sketches / sending them to owners for verification
• Development of Layout Sketches into formal ‘Property Plans’ for construction.
• Design of low pressure street main to link up Boundary Kits to trunk main.
• Optimisation of street connections to minimise disruption to roadway.

-Construction Planning

• Planning of installation methodologies with scheme construction contractors
• Supply of drawings, bills of materials and specifications to allow scheme construction pricing.

-Review of Okareka pump station to identify any upgrade requirements of specific system control requirements to manage flow from Tarawera into the pump station.

-Attendance at all project, review and design meetings.

-Progress and performance reporting.

-Safety, Environmental and Quality management and monitoring as required.

-Working with RLC appointed independent peer reviewer to ensure design is optimal for performance and operability.

-Development of concept design into detailed ‘for construction’ design.

You have the right to seek an investigation and review by the Ombudsman of this decision. The Ombudsman’s Office can be contacted by calling 0800 802 602, emailing info@ombudsman.parliament.nz, online at www.ombudsman.parliament.nz, or by post to The Ombudsman, PO Box 10152, Wellington 6143

Publication of responses to LGOIMA requests

Please note: Our LGOIMA responses may be published on the Rotorua Lakes Council website after they have been responded to, with requesters’ personal details withheld. If you have any concerns about this please contact the Council on info@rotorualc.nz.

Regards