Pittwater Online News

State Of Beaches 2022-2023 Report: Mona Vale Beach Downgraded - Most Other Swimming Spots 'Good'

Thursday October 19 2023

The Minister for the Environment has released the NSW State of the beaches 2022-2023 report, which shows 96% of monitored beaches have excellent water quality. Narrabeen Lagoon (Birdwood Park) Lagoon and Bilarong Reserve Lagoon are both rated 'Poor' again in water quality, while Palm Beach Ocean beach, Whale Beach Ocean beach and Avalon Beach are rated 'Very Good'.

Mona Vale beach has been downgraded to 'Good' with an increase in faecal contamination.

Of our Pittwater estuary swimming spots Bayview Baths is rated 'Poor' while The Basin and Great Mackerel Beach have been rated 'Very Good'. There remains an on-par with Hawkesbury river flood events and stormwater runoff amount of animal pollution being found at Barrenjoey Beach.

WaterNSW reported several occurrences of marine algal blooms along the Sydney coast in 2022–2023. Blooms of Alexandrium pacificum occurred in a number of estuaries including Broken Bay and Pittwater during October 2022 to February 2023. 

The confirmation of excellent water quality at almost all our beaches, up from 94% in 2021–2022 is a welcome result given the wet weather and flooding experienced over the reporting period. Many coastal areas experienced their wettest July on record, and more heavy rain and flooding through winter and in spring.

Four ocean beaches have been upgraded to very good – Coledale in the Illawarra, Fingal Bay and South Stockton Beach in the Hunter, and Malua Bay on the South Coast. Two ocean beaches have been upgraded to good – Toowoon Bay on the Central Coast and Caseys Beach on the South Coast.

Five ocean beaches have been graded as poor, including Malabar Beach which takes longer to recover from stormwater events than surrounding areas, and Coogee Beach where work is progressing to improve stormwater diversion.

Despite record rainfall, NSW swimming spots overall have performed well in the report. Seventy-three per cent of monitored sites received good or very good water quality results. It is a slight decline on 2021–2022, as a result of wet weather. Estuarine swimming sites are more susceptible to the effects of excessing rainfall and stormwater events, with just over half graded as good or very good.

State of the Beaches grades are compiled from water quality samples collected at sites monitored under the Beachwatch and Beachwatch Partnership programs. In 2022, Beachwatch expanded statewide to include inland waterways and freshwater swimming sites in the monitoring program. Sites include ocean beaches and baths, estuarine areas, lakes, lagoons and freshwater swimming spots.

Swimmers can check beach grades on the Beachwatch website at beachwatch.nsw.gov.au.

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

Minister for the Environment Penny Sharpe has stated, "As we head into swim season it is great news that 96% of our monitored beaches have excellent water quality.

"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.

"While 96% of beaches have excellent water quality, the Beachwatch website has real-time information for swimmers who want to check conditions after rainfall."

The ratings for all local beaches are as follows.

Ocean beaches

• Palm Beach Ocean beach -  Very Good
• Whale Beach Ocean beach  -  Very Good
• Avalon Beach Ocean beach  -  Very Good
• Bilgola Beach Ocean beach  -  Good
• Newport Beach Ocean beach -  Good
• Bungan Beach Ocean beach -  Good
• Mona Vale Beach Ocean beach -  Good
• Warriewood Beach Ocean beach -  Good
• Turimetta Beach Ocean beach -  Good
• North Narrabeen Beach Ocean beach -  Good
• Narrabeen Lagoon (Birdwood Park) Lagoon - Poor
• Bilarong Reserve Lagoon - Poor
• Collaroy Beach Ocean beach -  Good
• Long Reef Beach Ocean beach -  Good
• Dee Why Beach Ocean beach -  Good
• North Curl Curl Beach Ocean beach -  Good
• South Curl Curl Beach Ocean beach -  Good
• Freshwater Beach Ocean beach -  Good
• Queenscliff Beach Ocean beach -  Good
• North Steyne Beach Ocean beach -  Good
• South Steyne Beach Ocean beach -  Good
• Shelly Beach Ocean beach -  Good

Pittwater Estuary

• Barrenjoey Beach  -  Good
• Paradise Beach Baths  -  Good
• Clareville Beach  -  Good
• Taylors Point Baths  -  Good
• Bayview Baths Estuarine - Poor
• Elvina Bay  -  Good
• North Scotland Island  -  Good
• South Scotland Island  -  Good
• The Basin Estuarine  -  Very Good
• Great Mackerel Beach Estuarine  -  Very Good

Of the Pittwater to Manly sites, overall results show twenty-nine of the 32 swimming sites were graded as Very Good or Good in 2022–2023. This is a very good result and a similar performance to the previous year.

The best sites were Palm Beach, Whale Beach, Avalon Beach, The Basin and Great Mackerel Beach. These sites had excellent water quality and were suitable for swimming almost all of the time.

Bilgola Beach, Newport Beach, Bungan Beach, Mona Vale Beach, Warriewood Beach, Turimetta Beach, North Narrabeen Beach, Collaroy Beach, Long Reef Beach, Dee Why, North Curl Curl Beach, South Curl Curl Beach, Freshwater Beach, Queenscliff Beach, North Steyne Beach, South Steyne Beach and Shelly Beach were graded as Good. Water quality was frequently suitable for swimming during dry weather conditions, with elevated levels of enterococci recorded following heavy rainfall.

Mona Vale and South Curl Curl Beach were downgraded to Good, due to a slight decline in microbial water quality. The Beach Suitability Grade of Good indicates microbial water quality is considered suitable for swimming most of the time at Mona Vale but can be susceptible to pollution after rain, with several potential sources of minor faecal contamination.

Enterococci levels generally increased with increasing rainfall, occasionally exceeding the safe swimming limit after light rain, and often after 20 mm or more. The last time Mona Vale Beach was downgraded to Good was during the 2019-2020 report when again, elevated Enterococci levels reduced the water quality. 

Mona Vale recorded more than double the long-term monthly average rainfall for September and more than triple the monthly average for October with 203 mm and 260 mm of rain for the month, respectively. Significant wet weather at  the start of October included a daily rainfall total of 99 mm at Sydney Airport. Drier conditions followed in November with extended dry periods in some areas and below average rainfall recorded for the month. Mona Vale recorded 28 mm total rainfall for November, which was well below the long-term monthly average.

Over the data collection period for the report 35 Wet weather samples were taken and 65 Dry weather samples to record the quality of water off this beach as having 'Declined'. Overall it is reaching the same level of Enterococci levels as that of Warriewood, where faecal contamination sources include the Warriewood Wastewater Treatment Plant (WWTP). The report does not clearly identify the source of the increase in faecal contamination.

Contamination of recreational waters with faecal material from animal and human sources can pose significant health problems to beach users owing to the presence of pathogens (disease-causing microorganisms) in the faecal material. The most common groups of pathogens found in recreational waters are bacteria, protozoans and viruses.

Exposure to contaminated water can cause gastroenteritis, with symptoms including vomiting, diarrhoea, stomach-ache, nausea, headache and fever. Eye, ear, skin and upper respiratory tract infections can also be contracted when pathogens come into contact with small breaks and tears in the skin or ruptures of the delicate membranes in the ear or nose.

Certain groups of users may be more vulnerable to microbial infection than others. Children, the elderly, people with compromised immune systems, tourists, and people from culturally and linguistically diverse backgrounds are generally most at risk.

Mona Vale Beach, State of the Beaches report 2022-23

Just south of Mona Vale ocean beach, at Warriewood, the Beach Suitability Grade of Good indicates microbial water quality is considered suitable for swimming most of the time but can be susceptible to pollution after rain, with several potential sources of faecal contamination including  the Warriewood Wastewater Treatment Plant (WWTP). Enterococci levels generally increased with increasing rainfall, occasionally exceeding the safe swimming limit after 5 mm or more of rain, and regularly after 20 mm or more.

The Enterococci levels at Warriewood have risen steadily with this years' 'State of the Beaches' report recording the highest level for several years despite the report recording its status as 'stable':

Warriewood Beach, State of the Beaches report 2022-23

Warriewood Sewerage Treatment Plant currently provides secondary treatment and disinfection of sewage to a population of almost 65,000 people, according to WaterNSW.

The June 2023 Sydney Water report on Warriewood Wastewater Treatment Plant Summary of servicing strategy for 2022 – 2036 states:

Continued treatment of wastewater for discharge to ocean as per the current EPL (2018). The Capacity Assessment and Upgrade Option Report recommended a range of non-growth-related augmentations to improve the treatment system and meet service requirements through to 2056. These Reliability & Renewal (R&R) upgrades include:

• the addition of 2 clarifiers to the secondary treatment process, the modification of the mixed liquor splitting chamber, 
• introduction of WAS wasting from bioreactor and the installation of instrumentation to monitor nitrogen and phosphorous concentration

Further investigations:

The timing of these nominated R&R upgrades are dependent on when the existing redundancy constraints and associated operational risk with respect to reliably achieving the required effluent quality becomes unacceptable. 

EP-based methods attempt to determine dry weather flow empirically by estimating the number of equivalent persons (EP) within the catchment area and multiplying by an average wastewater production per EP.

Average Dry Weather Flow (ADWF)  to determine the average dry weather flow.

ML/d: Megaliters Per Day (= 11.574074074074 Litres Per Second)

Warriewood WWTP ADWF (ML/d) 2026: 17.5 (= 202.5462962963 Liters Per Second) and - to 2031: 18.3 

Warriewood WWTP load (EPCOD) to 2026: 90,647 - to 2031: 96,171 

No Treatment capacity constraints were identified for 2022 – 2036, and the Estimated year of exceedance is listed as not available in this report.

Turimetta Beach is also being impacted by the Warriewood Wastewater Treatment Plant. The report found:

'The Beach Suitability Grade of Good indicates microbial water quality is considered suitable for swimming most of the time but may be susceptible to pollution after rain, with several potential sources of faecal contamination including Warriewood WWTP.

Enterococci levels generally increased with increasing rainfall, occasionally exceeding the safe swimming limit after light rain, and regularly after 20 mm or more.'

Turimetta Beach, State of the Beaches report 2022-23

North Narrabeen Beach with a Beach Suitability Grade of Good indicates microbial water quality is considered suitable for swimming most of the time but may be susceptible to pollution after rain, with several potential sources of faecal contamination including discharge from Narrabeen Lagoon and the WWTP. This site also records in the 2022-23 State of the Beaches report animal contamination being found. Enterococci levels generally increased with increasing rainfall, occasionally exceeding the safe swimming limit after light rain, and regularly after 20 mm or more. 

North Narrabeen Beach, State of the Beaches report 2022-23

The Census usual resident population of Warriewood in 2021 was 8,380, living in 2,945 dwellings with an average household size of 2.85, an increase from  the 2016 Census, where 7,501 people were recorded as living in Warriewood. The 2022 Estimated Resident Population for Narrabeen is 8,107, with a population density of 1,769 persons per square km. The 2022 Estimated Resident Population for Mona Vale is 11,019, with a population density of 2,262 persons per square km. The 2022 Estimated Resident Population for Bayview is 3,673, with a population density of 1,029 persons per square km. The 2021 census lists 1,030 for Ingleside. In the 2016 Census, there were 9,301 people in Newport (NSW), for the 2021 9,659.

The Census usual resident population of Northern Beaches Council area in 2021 was 263,554, living in 105,115 dwellings.

Council's Development Activity Reports record $1,137,334,559.00 of approved DA's 1 July 2022 – 30 June 2023, including 2,269 lodged and 2,139 determined comprising; 1127 Residential alterations and additions, 293 New dwellings, 111 Secondary dwellings, 13 Multi-unit, boarding houses, seniors living, 5 Residential flat buildings, 10 Mixed use developments and shop top housing, 100 Commercial and industrial development and 93 Other.

The 2021/22 Financial Year records 2469 DAs were lodged and  2189 determined with a value of  $777,412,685.47 approved, comprising, Type (DA only); Residential Alterations / additions - 1103, New Residential Dwellings - 261, Secondary Dwellings - 137, Multi-unit Boarding Houses / Seniors Living - 12, Residential Flat Buildings - 11, Mixed use / Shop-top housing - 9, Commercial / Industrial - 89, Other - 124.

It is recommended that swimming be avoided at ocean beaches during and for up to one day following rainfall, or if there are signs of pollution such as discoloured water, flowing drains or floating debris, or a rise in faecal contamination.

Estuarine and lagoon swimming sites did not perform as well as ocean beaches due to lower levels of flushing, which increase the time needed to disperse and dilute pollution inputs, taking longer to recover from stormwater events.

Nine of the 10 estuarine swimming sites in Pittwater were graded as Very Good or Good in 2022–2023. The Basin and Great Mackerel Beach were graded as Very Good. These sites had excellent water quality and were suitable for swimming almost all of the time.

Elvina Bay was downgraded to Good from Very Good in the previous year. The microbial water quality at this site is close to the threshold between Good and Very Good and has changed between these grades over recent years. While water quality is mostly suitable for swimming during dry weather and after light to moderate rainfall, elevated bacterial levels were regularly recorded following heavy rainfall.

Barrenjoey Beach, Paradise Beach Baths, Clareville Beach, Taylors Point Baths, North Scotland Island, South Scotland Island and Elvina Bay were graded as Good. Water quality at these sites was suitable for swimming most of the time, with elevated levels of enterococci mostly recorded following rainfall. Bacterial levels were occasionally elevated at Barrenjoey Beach during dry weather conditions.

Bayview Baths was graded as Poor, a similar result to the previous year, and several years preceding that. Elevated enterococci levels were occasionally recorded during dry weather conditions, and regularly after moderate to heavy rainfall. Water quality at this site can take longer to recover from stormwater events than at other Pittwater swimming sites due to lower levels of flushing. There is also a dog water access area just south of Bayview Baths which would impact on the water quality as the tide draws out , taking with it the deposits of pets that have urinated or defecated at this spot.

Barrenjoey Beach with Suitability Grade of Good indicates microbial water quality is considered suitable for swimming most of the time but may be susceptible to pollution after rain, with several potential sources of faecal contamination, with the 2022-23 State of the Beaches report recording the highest incidence of this since 2021-22 and 2018-19.

Runoff from the Hawkesbury river and stormwater during storm events along with animal faeces remains the three highest causes of contamination here. Enterococci levels generally increased with increasing rainfall, occasionally exceeding the safe swimming limit after little or no rain, and often after 20 mm or more.

Barrenjoey Beach, under Barrenjoey Headland has had approval for amenities. In 2019, National Parks and Wildlife Service installed transportable toilets as a temporary solution while planning for a permanent amenity was underway. 

In late 2021, we engaged Aileen Sage Architects to develop initial concept designs for the toilets, which considered heritage constraints, visual impacts, environmental impact, visitor and access requirements, construction constraints and services provision.

The concept plans were released for community consultation from 4 April to 2 May 2022. The detailed plans are now complete. Applications for approvals have been submitted and are pending approval.

Procurement for the construction of this project will commence shortly. Construction is expected to begin in 2023, pending approvals and operational requirements. A works program, including the commencement date, will be circulated once a contractor is appointed.

However, one source of animal faeces is the offleash dogs that may be seen on the beach, and even going into the National Park, all day everyday, with Council unable to address the problem and dog-owners ignoring the signage in place.

Barrenjoey Beach, State of the Beaches report 2022-23

Barrenjoey Beach May 29, 2023

2 minutes later; Barrenjoey Beach May 29, 2023 - this group had taken their poodle into the National Park, albeit looking guilty as they loaded themselves into their car to depart

Same group passing by the signage on their return.

As a general precaution swimming should be avoided during and for at least one day after heavy rain at ocean beaches, and for up to 3 days in estuarine and lagoon areas, or if there are signs of stormwater pollution such as discoloured water or floating debris.

Swimming is not recommended at ocean beaches located near lagoon entrances if the lagoon is open, due to the possibility of pollution from the outflow. 

The 2 swimming sites in Narrabeen Lagoon, Birdwood Park and Bilarong Reserve, continued to be graded as Poor in 2022–2023, as in the previous year. Water quality at these sites was mostly suitable for swimming during dry weather, with 82% and 73% of dry weather samples within the safe swimming limit for Birdwood Park and Bilarong Reserve, respectively. However, enterococci levels increased with increasing rainfall, and often exceeded the safe swimming limit after light rainfall.

Birdwood Park is located at the entrance to the lagoon and water quality at this site is influenced by wet weather events and whether the lagoon is open to the ocean. Discharge from Narrabeen Lagoon is a significant source of faecal contamination.

Bilarong Reserve in Narrabeen Lagoon retains pollution inputs because it is located away from the lagoon entrance and is not well flushed by clean ocean water. A significant source of faecal contamination is stormwater runoff to the lagoon.

The amount of time the lagoon is open or closed influences water quality at Birdwood Park and Bilarong Reserve lagoon sites. During periods of entrance closure, water quality is likely to decline as pollution inputs are not as readily dissipated or flushed. The lagoon entrance will open and close naturally depending on how much rainfall has occurred and how much sand has accumulated in the mouth. When there are very large accumulations of sand, the entrance will often close and stay closed until the sand is removed by Northern Beaches Council. Historically this process is reported to happen every 4–5 years, with the last sand clearance operation being completed in December 2021. However, the rate of clearing required has increased in recent years to an average of once every 2 years.

Major clearance Works are currently underway, commencing September 25, at the Lagoon and expected to be completed by December 22, 2023.  These include reshaping the dune alongside the North Narrabeen SLSC Visit September report: Council Works To Open Narrabeen Lagoon Entrance Again: An Expense Recurring More Frequently

With the adoption of the Narrabeen Lagoon Entrance Management Strategy in September 2022, the council states it will be trialling more frequent but smaller sand clearance  operations (every 2–3 years rather than 4–5 years).

Narrabeen Lagoon entrance clearing works underway. Photo: Joe Mills, October 12, 2023