Our future has a past
The Tuggerah Lakes estuary has been shaped by a rich and vibrant history. It began with the early Aboriginal nations followed by the arrival of European settlers who triggered a wave in logging, fishing, dairying, tourism and urban development. Today, it is a bustling urban hub for approximately 140,000 people and a favourite destination for thousands of annual holidaymakers.
200 years of growth makes a mark
Almost 200 years of European settlement, industry and development in the Tuggerah Lakes catchment has had significant and long-term impacts on the local environment. The top impacts are:
- loss of vegetation from land clearing
- altered water flows from changed land use
- stormwater pollution (including sediments and nutrients)
Prior to development, forests covered the catchments of the Wyong River, Ourimbah Creek and Wallarah/Spring Creek. This land was steadily cleared for agriculture and timber during the 1800s and 1900s which caused severe erosion. With fewer trees to hold the soil together, sediment (naturally occurring material from rocks, soil or clay, broken down through weathering or erosion) and attached nutrients were washed from the catchment into the streams and rivers and eventually made their way into the lakes.
Activities that now occur in the catchment area generate larger amounts of sediment (from erosion) and nutrients than previously would have occurred prior to European settlement. Our waterways capture and transport all of these pollutants downstream. Pollution from forestry, land clearing and development, agriculture and turf farming, industry, sewerage overflows, road runoff, and the use of plant fertilisers, cleaning products and organic matter around the home all affect our waterways. High levels of pollutants are bad for the health of the estuary and can reduce the water clarity, cause algae and phytoplankton blooms, reduce fish populations and upset the healthy balance of the estuary and everything that depends on it.
Fertiliser used on farms in New South Wales increased sharply from the 1950s. Rain can cause fertiliser to dissolve and flow into the lakes. While nutrient levels have decreased from their peak in the 1960s and 1970s, there are still some industries in the catchment that continue to use fertiliser.
early logging 1820’s
flooding from lakes 1900
boating on lakes 1920’s
the entrance 1920’s
entrance early 1980’s
In the early 1900s, there was no treated sewerage system in the lakes’ catchment. Each house used a pit toilet and cast the dirty water from washing and bathing into the drains which eventually flowed into the lakes. This only had a small impact when there were just a few houses in the area but as the population swelled something had to be done. At this point in time the lakes were considered to be a nutrient poor system, which is the natural state for Tuggerah Lakes.
Town water was connected in the late 1950s which brought with it flushing toilets and septic systems. As the volume of grey water increased so did the amount of pollution entering the lakes. The impact of the extra nutrients on the lakes was that the environment went from being nutrient poor to one with an excess of nutrients. This caused problems such as larger algal blooms and dieback of seagrass beds.
A treated sewerage system was finally introduced between 1960 and 1990 which pumped sewerage to treatment plants and away from the lakes. Over time this change has allowed the nutrient level in the lakes to drop, so now they are considered to be of a medium nutrient level.
Photo: Stormwater treatment device in Kanwal to prevent rubbish and sediment entering the waterways
Before the paved roads and buildings, most of the catchment’s rainfall would have soaked into the ground. However urban development has significantly increased the amount of runoff, particularly during heavy rainfall, which flows into the lakes. Stormwater is usually directed down concrete drains and watercourses carrying with it soil from building sites, leaves, fertilisers from gardens, litter from footpaths and streets, oils from roadways and pollutants from factories. This runoff is one of the main causes of high nutrient levels in the lakes which can lead to excessive growth of algae and aquatic plants. Over the past decade, the Council has been making improvements to our stormwater infrastructure such as installing vegetated swales, constructed wetlands, sediment traps, trash racks and filter strips on stormwater drains to try and reduce the problem. Education campaigns have also been run to raise public awareness of how the community can help.