Groundwater extraction to resume under Water Plan

Central Coast Council's groundwater extraction "borefield" on the Peninsula, which "has been operating in standby mode", would be brought online in around three years, according to the council's draft Water Security Plan.

An associated leaflet supporting the groundwater option states: "Council is looking to provide five megalitres per day from groundwater, commencing the production output at the Woy Woy Groundwater Treatment Plant to produce three megalitres per day and refurbish the existing Mangrove Creek and Bangalow borefields to produce approximately two megalitres per day."

The cost is estimated to be 66 cents a kilolitre - "the lowest levelised cost compared with Council's other shortlisted options".

The cost to build the option is just $500,000, because "the majority of required infrastructure is currently in place". Annual operating cost is estimated at $400,000.

However, the yield "is relatively low compared to other options", several of which cost more than $100 million to build.

The leaflet described the reliability and resilience of groundwater extraction as high, as "natural underground reservoirs provide a reliable source of water, but still rely on rainfall to recharge".

It claimed environmental impacts are low, with "low energy use dependent on the level of treatment provided".

It stated that environmental baseline monitoring was required to ensure potential ecological risks were understood and managed.

It also claimed social and cultural impacts were low, with "community interest in process, reliability and safety".

The delivery timeframe was three to seven years.

The draft plan states: "Groundwater can be a replenishable and sustainable source of water.

"Our approach to recommissioning and enhancing our groundwater use includes restoring the existing groundwater systems at Woy Woy, and monitoring the performance and impact on extraction for long-term sustainable practice."

Actions listed in the plan include investigating the sustainable yield for groundwater at Woy Woy, and ongoing performance monitoring of extraction on the groundwater for a sustainable yield.

In a frequently-asked questions section, it is stated that Central Coast Council has an existing licence to extract and treat groundwater from the shallow aquifer at Woy Woy Peninsula.

"Existing government regulations are in place to ensure that Council extracts groundwater in a sustainable manner.

"The extraction of groundwater by Council is governed by licence conditions and water sharing plans regulated Department of Planning Industry and Environment.

"Regular environmental monitoring is undertaken to assess potential impacts of groundwater extraction on the aquifers and environment, including Groundwater Dependent Ecosystems."

However, no detail of the monitoring has been included in or with the draft plan.

"Further environmental and hydro-geological investigations will be undertaken at existing and potential groundwater extraction locations to confirm the yield potential of the aquifers as well as any environmental impacts of increased extraction.

"As part of the Central Coast Security Plan, Council proposes to utilise the existing groundwater allocation and investigate the potential to increase extraction of water within the current limits set in place and regulated by the Department of Planning, Industry and Environment."

The plan is on exhibition for public comment until September 28.

SOURCE:

Website, 17 Sep 2021

Draft Water Security Plan, Central Coast Council