GENFLO Sand Bypass System

The Sand Bypass System is a permanent solution to sand erosion and littoral drift problems affecting river mouths and navigation channels worldwide.

Example:
The Problem
The Nerang River entrance to the Pacific Ocean, a centre for commercial and recreational boating alike, has suffered from instability due to a strong northerly drift along the shoreline. This means that the river mouth is constantly moving, sometimes as much as 60m in a year. This has resulted in land erosion, ever-changing and unpredictable sand banks, many boating accidents and risk to property and business.

The Solution
Extensive research revealed that with the magnitude of the northward drift of the sand along the coastline, some 500,000 m3 a year, any scheme to stabilise the river entrance would also need to artificially bypass sand across the river mouth indefinitely.

As no comparable system existed, Queensland Transport developed what would become a world-first, globally recognised sand bypass solution.

The system consists of a steel-framed jetty from which a number of jet pumps (10 at the Gold Coast, 6 at the port of Ngqura) are suspended and submerged below sea-level. Sea water is used to activate these pumps and lift sand from the sea bed, decanting excess water back into the ocean and forcing the concentrated sand through an underground pipeline which runs under the seaway entrance, depositing it onto the beach at the other side. Automated computer control and monitoring ensures maximum economy and efficiency at all times.

The Gold Coast Sand Bypass System has been in operation for over 10 years. It has proven highly effective and more cost-efficient and sustainable than dredging. The annual operating costs of the system are around one-quarter of the annual dredging costs, and much more effective. The system has also contributed to enhancing and preserving a natural environment, which offers safe passage for recreational and commercial water pursuits alike. Increased tidal flows have also significantly improved water quality and fishing in the region.