8.4: Water Issues

Water Consumption on the Central Coast

CentralCoast water supply system provides water for about 300,000 people in Gosford City and Wyong Shires. The average water use on the Central Coast is 70 megalitres per day.  Figure 1 shows that the mean daily water use on the Central Coast has steadily declined since 2001 owing to the impact of drought, various restrictions imposed by the Gosford/ Wyong Councils’ Water Authority, and by individual actions of consumers.

 
Figure 1:   Mean Daily Water Use on the Central Coast between 2001 and 2011 
 

Back in 1985, the average daily consumption of water divided by the estimated population connected to the water supply on the Central Coast was as high as 470 litres. By 2001 this had been reduced to 329 litres per person per day. Note that this figure is based on all categories of water use, including residential demands, government, commercial and industrial demands, as well as unaccounted-for water use.

The percentage of water consumption by customer category is set out in Figure 2. State and Local Government, commercial and industrial demand consumes approximately 22% of the annual supply. Residential demand is typically around 68%, with system leakage and unmetered use (known as unaccounted for water) representing the remaining 10% of annual supply.

Figure 2:  Water Consumption by Customer Category on the Central Coast
(Source: Preliminary working draft of WaterPlan 2050; A long-term water supply strategy for the Central Coast)

 The following is a brief description of each category of customer represented in the graph:

Government consumers

The Department of Housing, Department of Education and Gosford and Wyong Councils are major government consumers of water. The Department of Housing manages public housing on the Central Coast. The Department of Education manages schools and higher education facilities. Gosford and Wyong Councils are also major consumers supplying all Council facilities including Council Chambers and depots, libraries, child care centres, sporting complexes, surf life saving clubs, beaches and parks and gardens. Between them these Government consumers represent approximately 7% of the Central Coast’s water use.

Commercial consumers

Commercial consumers include organisations office buildings, shopping centres, and a wide variety of small businesses such as restaurants and food outlets. Because of regulations, newly established commercial buildings are more efficient users of water than older commercial buildings. Commercial consumers represent approximately 6% of the water use.

Industrial consumers

Industry uses approximately 9% of the Central Coast’s annual water consumption with the major users like Vales Point power station using approximately 4%.

System water losses

Gosford and Wyong Councils own and operate the Central Coast water supply system which is subject to leakage and other unaccounted for water (UAW) use. As with all water supply systems, the leakage can be through a mixture of cracked pipes, leaking joints and faulty hydrants and valves. UAW is also water used to flush mains, clean reservoirs and in some instances supply unmetered Council uses such as parks and garden watering. It also includes water used for fire fighting. By its nature, it is difficult to quantify the volume of water used annually. UAW typically accounts for approximately 10% of total water demand.

Residential consumers

When unrestricted (i.e. in the absence of limitations on consumption), approximately 70% of residential water use is indoors and 30% is used outdoors, principally for garden watering.

For much of the past decade, New South Wales was in the grip of one of the worst droughts in recorded history. By the beginning of 2007, dam storage levels on the Central Coast had fallen to less than 14%.  Because of this falling level of storage over recent years, the Gosford/Wyong Councils’ Water Authority responded with:

1. a program of imposed  water restrictions designed to reduce current water use
2. a campaign of customer education and support to reduce water use by the community
3. the implementation of key initiatives from WaterPlan 2050, including the construction of the Mard-Mangrove Link

Water Wise Rules
The program of graduated water restrictions on the Central Coast is based on the measured water storage levels, with increasingly severe restrictions being imposed as storage levels decline. Table 3 lists the regime of restrictions adopted on the Central Coast and the estimated reduction in water consumption intended by each level of restriction.
 

Table 1: Current Water Restriction Regime of the Gosford/Wyong Councils’ Water Authority
(Source: Preliminary working draft of WaterPlan 2050; A long-term water supply strategy for the Central Coast)

 

 

Restriction Level	Initiate Restriction when Mangrove Creek Dam Reduces to	Remove Restriction when Mangrove Creek Dam Rises to	Target Reduction during Restriction Level
	2012	2012	2012
Level 1	42%	44%	8%
Level 2	34%	36%	16%
Level 3	30%	32%	24%
Level 4	26%	28%	27%
Level 5	22%	24%	30%

 

Figure 3: Water Tank installed at Chittaway Public School (Source: Wyong Shire Council)

Water Wise Rules

Effective 14 May 2012, and after more than a decade, Central Coast Water Restrictions were been lifted and the region is now guided by permanent Water Wise Rules.

Under Water Wise Rules, there are no formal water restrictions on the NSW Central Coast.

However, people in the area are asked to follow a series of water conservation guidelines known as Water Wise Rules. Being Water Wise means:

Lawns and gardens

Watering with a sprinkler, irrigation systems and trigger nozzle hose is okay any day before 10am and after 4 pm to avoid heat of the day.

Vehicles and boats

All road vehicles (including cars, trucks, caravans and cars in car yards) may be washed with a bucket or a hose provided a trigger nozzle or pressure cleaner is used.

All boats (including all water craft and boat trailers) may be washed with a bucket or a hose provided a trigger nozzle or pressure cleaner is used.

Flushingof boat engines with a hose is permitted.

Hard surfaces

No hosing of paths and driveways.

Private pools and water activities

Topping up of existing pools using a hose from the town water supply is permitted.

Bowling greens, cricket pitches and golf greens

Watering including with sprinklers, irrigation systems and hand held hoses fitted with a trigger nozzle is permitted any day before 10am and after 4 pm to avoid heat of the day.

Nurseries and commercial gardens

Watering including with sprinklers, irrigation systems and hand held hoses fitted with a trigger nozzle is permitted any day before 10am and after 4 pm to avoid heat of the day.

Sporting fields, school ovals and grassed areas

Watering including with sprinklers, irrigation systems and hand held hoses fitted with a trigger nozzle is permitted any day before 10am and after 4 pm to avoid heat of the day.

Water cartage from town water supply

Permitted.

Auto flush urinals

Timer controlled operation  is not allowed.

Public beach showers, fish tables and boat ramp taps

Using these is fine.

Annual demand greater than 3,500 KL and hotels, motels, resorts, caravan parks and public pools

Preparation and implementation of an approved water management plan is necessary.

Voluntary daily water use target

This is 150 litres per person.

Note: No restrictions apply to the use of town water in the event of, or where there is a risk of an accident, fire, hazard to health, safety or environment.

Water Consumption

Compared to other parts of Australia, water consumption per capita has not been excessive on the Central Coast; Figure 4 compares the consumption per capita on the Central Coast in the year 2001, in 2007 with Level 4 restrictions, and as predicted for 2051, alongside the current per person consumption in a number of other cities. This consumption per capita is calculated by dividing the total system demand (residential, government, commercial, industrial demands and UAW) by the total serviced population.
 

* Per capita water consumption is calculated by dividing the total system demand (residential, government, commercial, industrial demands and UAW) by the total serviced population.

Figure 4: Comparison of Water Consumption per Capita*  
(Source: Preliminary working draft of Water Plan 2050; A long-term water supply strategy for the Central Coast)

The impact of the drought and water restrictions can be observed in Figure 5.

Figure 5: Average Daily Water Consumption Recorded Weekly between 2002 and 2007.
(Source: Data derived from the Internal Memo for the Gosford/Wyong Councils’ Water Authority Board, August 2007 )

The campaign of customer education and support implemented by the Gosford/Wyong Councils’ Water Authority has the objective of reducing current water consumption per capita significantly over the next few decades as indicated in Table 2.

Table 2:  Projected per Capita Water Consumption * on the Central Coast up until 2051
(Source: Preliminary working draft of WaterPlan 2050; A long-term water supply strategy for the Central Coast)

 

Year	1985	2001	2011	2021	2031	2041	2051
Per Capita Water Use (Litres per person per day)	470	329	311	296	288	285	282

* Per capita water consumption is calculated by dividing the total system demand (residential, government, commercial, industrial demands and UAW) by the total serviced population.

The kinds of measures that will be required to achieve these reductions in per capita consumption are listed in the Table 3.

  

Figure 6: Water Wise Gardening (Source: Gosford City Council, 2007).

Table 3:  Summary of Demand Management Measures
(Source: Preliminary working draft of WaterPlan 2050; A long-term water supply strategy for the Central Coast)

 However, even with these measures, the total water consumption will rise because the population of the Central Coast is expected to increase substantially over the same period.  Total water supply will need to expand to keep pace with this population growth (Table 4). Plans are in place to expand supply to meed this expanded total demand.

Table 4: Predicted Total water Demand on the Central Coast up until 2051
(Source: Preliminary working draft of WaterPlan 2050: A long-term water supply strategy for the Central Coast)

 The residential component of water use is of particular concern to the Water Authority in its efforts to meet these targets. Residential households consume 68% of the water used on the Central Coast. This water use by households is made up of several components both within the house and outside the house (Table 6).

Table 5: Categories of Water Use by Residential Consumers on the Central Coast (Source: Gosford/Wyong Council's Water Authority).  

 

Residential use before restrictions	Residential Consumption (%)
Internal Usage
Toilets	16.9%
Baths	2.2%
Showers	23.7%
Taps	5.0%
Dishwashing	2.2%
Laundry	19.8%
Internal Leakage	2.2%
Total Internal	72.0%
External Usage
Garden Watering	21.0%
Swimming Pools	4.2%
Outdoor other (e.g. Car Washing)	1.7%
External Leakage	1.1%
Total External	28.0%
Total Residential	100%

  
   

Figure 7:  Swimming pool (Source: Wyong Shire Council)

Figure 8: Pool cover (Source: Wyong Shire Council)

Measures that Gosford and Wyong Councils have taken to educate and support householders in reducing their use of water have already had a major impact. Installation of household water tanks, repairing leaking taps, installing and using water saving devices like dual-flush toilets and 'water saver' shower heads, and the adoption of  water-wise gardening practices are just some of the steps that householders have taken to reduce their demand upon the water supply system (and  reduce their own water bills).

According to the 2006 Performance Report of the National Water Commission, average annual residential water use by Central Coast households was one of the lowest in Australia during 2005/06 compared to the country’s other major urban water utilities (Table 7).  

Table 6: A Comparison of Annual Residential Water Use per Household in different Australian Water Authorities in 2005-06
(Source: National Performance Report of the National Water Commission)

 

Water Authority	Average annual water use per household (litres/household/year)
GCC	180,000
City West (Melbourne)	183,000
Brisbane	185,000
Melbourne(3 providers)	191,000
Gold Coast	200,000
Sydney	203,000
Hunter	204,000
SA Metropolitan	233,000
ACT	261,000
PerthMetropolitan	268,000
GoulburnValley	315,000
Northern Territory	443,000

The immediate goal of the restrictions, education, and customer support measures adopted by Gosford and Wyong Councils is to see average household water use on the Central Coast reduced below 150 litres per person per day. A key part of the Central Coast WaterPlan 2050 is to encourage people to continue their water conservation efforts for the long-term, to achieve a sustainable reduction in demand even without imposed water restrictions.

 

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