State of the Beaches report rates Wentworth Falls Lake water quality as 'poor'

The State of the Beaches report for 2022-23 released on October 17 is the annual rating of ocean and estuarine swimming sites across NSW using Beachwatch results and provides an overview of water quality at 214 swimming locations. It is the first time these Mountains waterways have been included in the results after Beachwatch expanded statewide in 2022 to include inland waterways and freshwater swimming sites in the monitoring program.

According to the DPE a reading of "poor" means the waterway is "susceptible to faecal pollution and microbial water quality is not always suitable for swimming". A "very poor" reading means it is "very susceptible to faecal pollution and ... it is generally recommended to avoid swimming at these sites almost all of the time".

But Blue Mountains Council says poor health results have been impacted by three years of La Nina rains. New expanded monitoring means residents will now have access to weekly water quality ratings so they can make informed decisions about swimming.

"The truth is that Blue Mountains waterways are generally healthy. This includes Wentworth Falls Lake," Mayor Mark Greenhill said.

"It would be misleading for anyone to read small parts of this report and not take into consideration that the results are skewed from three years of La Nina data. It is important to responsibly discuss this data and not dramatise it and frighten the community unnecessarily."

Council has been monitoring recreational water quality in the Blue Mountains since 2002.

A rollout of new water quality signage, which include QR codes linking to weekly testing data, has started this week.

A council spokesperson said 2022-23 was the first time in a long time that the Wentworth Falls Lake 'beach' site received an annual grade of 'poor' rather than 'good'.

"This is likely due to this five-year dataset now including three consecutive La Nina years with much higher than average rainfall so much greater stormwater inputs."

Council said water quality from the lake had been "good" from 2016 onwards and was downgraded to "poor" in 2023 because of "exceptional conditions". And while recent annual water quality ratings for Minnehaha Falls had tested as poor, the first round of weekly Beachwatch star ratings have tested Minnehaha Falls as 'good'.

The NSW-wide report stated that "despite the 'poor' grade, water quality at [the lake] is mostly suitable for swimming during dry weather conditions, with 77 per cent of dry weather samples within the safe swimming limit. This site can be susceptible to wet weather impacts and has several sources of faecal contamination including stormwater and animals".

The report further stated the Minnehaha site has "several potential sources of faecal contamination identified in the sanitary inspection, including stormwater, sewer chokes and impacts from upstream sources in Yosemite Creek".

Between October and March council takes weekly water samples at popular local waterways, to test for bacterial contamination and provide advice on swimming suitability.

These sites include Megalong Creek (Old Ford Reserve), Minnehaha Falls (Yosemite Creek) and Wentworth Falls Lake beach and jetty. The information appears on council's website and in their annual Waterways Health Snapshot. Council is working in partnership with the NSW Department of Planning and Environment's Beachwatch program, making the results of its water quality samples accessible via the Beachwatch website.

The grades reported in the State of the Beaches report are 'annual grades' based on the last five years of actual faecal bacteria data combined with a risk assessment. There are also weekly 'star ratings' to categorise each site's suitability for swimming as either 'good', 'fair', 'poor' or 'bad', depending on the levels of the bacteria detected in water samples.

NSW Environment Minister Penny Sharpe said "rainfall is the main reason water quality changes, and we had a lot of it in 2022".

"As a result, many inland and freshwater swimming sites did not perform as well as our ocean beaches."

The annual DPE report showed 96 per cent of monitored beaches had excellent water quality but almost a quarter of the state's favourite swimming spots were found to have been polluted by heavy rains over the past year.

A council spokesperson said water quality was variable depending on weather and conditions could change on any day, even in dry weather.

"For example, the latest testing from last week rated Minnehaha as 'good', and Wentworth Falls Lake beach as 'fair'," the spokesperson said.

Updated signage will be trialled this year at Megalong, Minnehaha and Wentworth Falls Lake with QR codes linking directly to the latest test results for that site.

Current signage at Megalong Creek and the lake has advice for swimmers. Signs at Minnehaha advise swimmers not to drink the water.

Council is encouraging residents to check the weekly water quality results at beachwatch.nsw.gov.au. Water safety precautions also exist on the council website.

Council recommends avoiding contact with waterways in rain and three days after rain and to check ratings on the Beachwatch website before deciding to swim. It also advises to keep your head above the water (keeping water out of ears, eyes and noses) and to remember that the "very young, very old and those with compromised immunity are at greater risk of illness due to contact with poor quality water".

There are 12 stormwater biofilters (raingardens) built in the lake and Jamison Creek catchment and on average they remove 63 per cent of faecal coliforms from stormwater before it enters the lake or creek.

Residents can help by managing run off and picking up dog poo and other pollutants and reporting sewage leaks or other suspected pollution sources.

The NSW State of the beaches 2022-2023 report can be viewed online.