Charleston Dam was designed to provide town water to Forsayth and to Georgetown as well as creating the site for a new recreational facility at the reservoir. Charleston Dam was constructed from June 2019 through December 2020, at which time ownership was handed to Etheridge Shire Council (ESC), which included the responsibilities for operation and maintenance of the dam. Charleston Dam consists of a zoned earth fill embankment with a clay core, general fill, upstream and downstream rock protection, and a sand filter. The dam comprises an unlined spillway channel with a buried left abutment mass concrete training wall. The dam outlet works consist of a floating offtake, with no provision for environmental releases through the dam itself. The dam has a capacity of 10,900 ML with a catchment area of 206 km2.

Charleston Dam includes a fishway located on the right bank forming the full supply level of RL 387.30 m AHD. The fishway comprises a 1,045 m long (approx.) structure with an uncontrolled entrance at the Delaney River, traversing along a natural gully with excavated resting pools, two rock ramps and finally a further series of resting pools along the spillway crest before exiting into the reservoir. The available documentation on the fishway is listed in Section 4 including drawings, which is included in:

https://shepherdservices.sharepoint.com/:b:/s/Intranet/Efs49RF5XPtKkmMl1uylBvABmDTd fi8CcDz0_y0s6Zme1w?e=dd5M6

Scope of works

The scope of works for the detailed design of the rock ramp is subject to consultation with SARA and DAF as part of the approvals process. As such, the scope of works may vary depending on the design and advice from agencies. Notwithstanding, the scope of works should include at a minimum:

1. All project management related activities, including one site visit, quality assurance and health, safety and environment activities required to undertake the works. At a minimum, monthly progress meetings.

2. Develop concept design drawings and basis of design document for submission to SARA and DAF for technical feedback prior to meeting.

3. Prepare estimated construction cost based on concept design (project is externally funded under Disaster Recovery Funding Arrangements, keeping the Queensland Reconstruction Authority informed on estimated cost is important).

4. Prepare an agenda and presentation to present the concept design (as a proposed minor change) to SARA and DAF during a formal pre-lodgment meeting. 

a. Hold point: Confirmation of design concept and scope of works required to progress to detailed design and approval.

5. Prepare detailed design documentation, Planning Act Form 5 Change Application Form and supporting information report including Assessment against State Code 18 and submit to SARA and DAF via MyDAS2. As the works are considered to be remediation in line with the design intent and development approval, the change is expected to be Minor.

6. Prepare an estimate of construction costs based on final design.

7. OPTIONAL: Preparation of full tender documentation for tendering the construction of the works using FNQROC template documents.

8. Provide an hourly rate to assist with any technical enquiries from potential construction contractors during the tender period.

9. OPTIONAL: Provide an hourly rate to provide assistance with tender assessment.

10. OPTIONAL: Completion of DA related construction forms as required to meet notification and reporting requirements

11. OPTIONAL: Undertake technical inspections during construction, respond to technical queries from the contactor and certify the construction.

Exclusions

The following activities are considered outside of scope based on the existing development approval and advice to date, however dependent on advice from SARA and DAF as the design is progressed:

1. Assessment of alternative fishways or a fishway options assessment

2. Major amendment requiring additional design work or planning applications.

3. Hydraulic modelling of the fish passage or fishway internal hydraulics

4. Geotechnical investigations

5. Ecological investigations

6. Further information requests from SARA/DAF during the change application process

7. Application fees (these shall all be paid by ESC)

Timeline

The following timeline is suggested based on the Scope of Works and exclusions:

1. Engage consultant to undertake remediation design: 21 November 2023

2. Prepare concept design package: 12 January 2024

3. Approval in principal of concept by SARA/DAF: 19 January 2024

4. Detailed design: 13 February 2024

5. Submission of Approval change notification: 20 February 2024

6. Approval: 30 March 2024

7. Tender Advertised: 1 April 2024

8. Tender Award: 10 May 2024

9. Construction: May to August 2024

Mandatory requirements

1. All stages of design shall include oversight and advice from a suitably qualified and experienced fish passage professional in accordance with SDAP Guideline State Code 18: Constructing or raising waterway barrier works in fish habitats

2. All stages of design shall include oversight from a Registered Professional Engineer of Queensland (RPEQ).

3. Any modifications to the dam (including spillway) shall be certified by an experienced dam engineer who is RPEQ in accordance with the Queensland Dam Safety Management Guidelines and Dam Safety Condition Schedule for Charleston Dam.

4. The design shall be in accordance with the development approval, and/or as otherwise approved by the assessing agency.

Proposal

Suppliers are asked to provide a proposal outlining their understanding of the project, proposed methodology including risk identification and management approach, team (including experience), program and price for the nominated scope including details of resource time allocation and hourly rates.