14 December 2023

Water security and environmental benefits flow from Seaham Weir upgrade

Hunter Water is completing upgrades to the Seaham Weir to improve safety, enable effective water flow management, and improve fish passage.

Located on the lower Williams River, the weir is an essential component of the Grahamstown Dam scheme, which provides 40% of the drinking water used by Hunter Water customers.

Seaham Weir separates saline tidal water from where fresh river water is pumped to store in Grahamstown Dam. The upgrades allow, for the first time, a set portion of the flow in the Williams River to be passed through to the estuary daily, providing improved environmental outcomes for the estuary and much better attraction flows for migrating fish.

Hunter Water Managing Director, Darren Cleary, said the more than 50-year-old asset is part of a broader Hunter Water program to replace and upgrade water and wastewater related assets across the region, bringing them to a standard that meets modern day environmental expectations.

"We've invested $15 million at Seaham Weir to upgrade the river flow gates and the fishway to deliver even more effective water flow management, maintain the weir pool's water level and improve fish passage for migration and spawning.

"As a business, we're continuously working to improve our infrastructure to ensure we are delivering quality outcomes for both the community and the environment in which we live," Mr Cleary said.

Modifications to Seaham Weir and associated changes to the water-sharing rules that govern its operation were included as recommendations in the Lower Hunter Water Plan that was developed in 2014. The LHWP set out measures to ensure enough water to supply the needs of the Hunter Region and, at the same time, improve environmental outcomes at Seaham Weir and Chichester Dam through changes to their water release patterns.

Upgrade work at Seaham Weir has included:

  • installing four new low-flow gates on the weir's eastern side to allow controlled release of water into the estuary on an ongoing basis
  • installing a new fishway on the weir's eastern side for improved fish passage both up and down the Williams River
  • refurbishment of the existing weir gates on the weir's western side.

The upgrades serve as a timely reminder of the importance of water security in our region.

"Our community increasingly expects Hunter Water to improve our region’s water resilience, and while this project upgrade works towards that, it’s also a reminder of how we can work together to ensure we are making the most of our water supply; there's no time to take drinking water for granted.

"Our community has continued behaviours learned in the last drought, saving about 10

per cent on what we would expect the community to use, but the forecasts are for a hot, dry summer, so let's make the most of what we have and save our most precious resource," Mr Cleary said.