Release of Coastal Engineering Scoping Study for a Tidal Swimming Facility: Port River, Adelaide

The Coastal Engineering Scoping Study for a Tidal Swimming Facility: Port River, Adelaide has been finalised and is now being released, following consideration and support from the North Haven Surf Life Saving Club and an impending decision by the City of Port Adelaide Enfield

The Study was commissioned from the Water Research Lab, UNSW after fundraising by ECF with its partner, the North Haven SLSC.

The Study considered 4 potential sites in the inner harbour from Cruickshanks Corner to the Joyce Snadden Reserve.

Concept designs could not be developed for 4 sites (given the available funds) so after considering environmental factors, it was decided to develop designs for a Cruickshanks Corner site (see cover photo).

The recommended option (Concept Design 1) for Cruickshanks Corner is

• A beach-entry pool (including initial beach nourishment), with the (periodic) addition of additional sand if required
• Netting on three sides, with additional studies needed to confirm a low hazard to dolphins
• A continuous timber jetty/walkway on three sides to provide overwater space (especially for swimmers to relax and locals/tourists to enjoy walking in close proximity to the Port River)
• Lap swimming area of 50 m length, with lane ropes deployed at busy times
• Accessibility ramp and pontoons, plus ladder access to lap swimming area
• Ancillary structures on the land – toilets, change rooms, showers, shade structures, tables and seating

The indicative Capital Cost for Concept Design 1 is $3.29m and annual maintenance cost is est $110,000.

A wonderful example of a pool with a continuous walkway is Balmoral Beach – photo below

Study details:

The following site specific environmental constraints (section 3) were assessed
– Water Quality – tidal levels & flushing, inflows, stormwater, water quality measures, circulation concerns
– Storm surge
– Bed Sediments – sediment quality, size
– Dolphins
– Shellfish & Barnacles
– Boat Activity
– Wave climate

In relation to Water Quality the Study concluded that “it appears that swimming at the four potential tidal sites is safe assuming that the guidance to avoid swimming for 2 to 3 days after rain is followed”.

Bed sediments (at a site north of Derek Diver bridge in 2020) showed that elevated concentrations of mercury, lead, zinc and copper persist in the River, likely due to legacy contamination. Any swimming facility in the Port River needs to minimise disturbance of bed sediments during construction and use (e.g. sand cover).

The Study considered these tidal pool design elements

– Perimeter/screen wall
– Ramp entry
– Public space
– Lifeguards
– Pool shell and floor
– Pontoons
– Lap swimming aids

The Water Research Lab advised that beach Entry (zero entry) is a feature of ‘better existing tidal pools’, allowing pool access to more people e.g. children, weak swimmers, people with low mobility etc. In the Port River beach entry would need beach nourishment to cover sediments.

ECF and the NH SLSC had always anticipated access via a walkway/jetty and so the Study considered 2 options with beach entry (designs 1 and 2) and 2 via a walkway (designs 3 and 4)

Capital costs range from $3.29M (design 1) to $1.52M (design 4) while annual maintenance costs range from $110K to $90K respectively.

NH SLSC support:

Prior to the Scoping Study going to donors, the findings and proposals were shared with members of the North Haven Surf life Saving Club at their AGM on Saturday, July 15th.

Catherine McMahon, ECF gave a presentation to members, reminding them of the origins of the project and advising of the findings and proposals from the Study and the likely next steps to advance the project.

There was unanimous support when President Glen Gallagher asked voting members if they wanted the Club to continue its advocacy for the project  with ECF.

Attendees at NH SLSC AGM 2023

NH SLSC Committee members at the AGM

ECF subsequently began discussions with the City of Port Adelaide Enfield, with ECF providing a ‘dinner’ briefing to Councillors on September 5th and Council to consider its formal response to the study at its November 14th meeting.

The Coastal Engineering Scoping Study for a Tidal Swimming Facility: Port River, Adelaide was made possible by a donation of the Suzanne Elliott Charitable Trust, a GoFundMe campaign (with 27 donors) and matching donations from Kite Projects and the City of Port Adelaide Enfield.