1345.4 - SA Stats, Jan 2007  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 30/01/2007   
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Image: Environment


ENVIRONMENT


WATER IN SOUTH AUSTRALIA

During spring and early summer, water and rainfall is frequently discussed in the media in South Australia.

The main sources of water for South Australian households and businesses are local reservoirs (usually providing about 50%), the River Murray (normally providing just under one half) and groundwater (providing under 10%) (SA WATER, Annual Report 2004-05). Given that more than half of the water provided to South Australian households and businesses is from reservoirs, rainfall is of critical interest. In the Mt Lofty Ranges catchment areas of South Australia's main reservoirs, the winter (June, July and August) of 2006 was the driest on record, and the first 2 months of spring (September and October) were the driest since 1914 (Bureau of Meteorology, Archive of SA and Adelaide Monthly Climate Summaries). As at 30 November 2006, the main reservoirs were about 42% below capacity (SA WATER, Reservoir levels).

South Australian pastoral districts and agricultural districts are mainly reliant on rainfall for their water needs. During the winter and early spring of 2006, these districts generally experienced below to very much below average rainfalls (Bureau of Meteorology, Archive of SA and Adelaide Monthly Climate Summaries). The southern and south-eastern parts of the agricultural districts and the Eyre Peninsula were particularly affected by the dry conditions.


RAINFALL IN SOUTH AUSTRALIA

The Bureau of Meteorology described South Australia's 2006 spring weather (September, October and November) as 'extremely dry' with rainfall 'significantly below average'. Winter was described as 'very dry' with winter rainfall 'very much below average' over the Agricultural areas. In autumn (March, April and May) much of the State experienced 'average to below average' rainfall.

RAINFALL IN ADELAIDE

Adelaide commenced 2006 with above average rainfall for the summer months (January and February) and autumn season. However, Adelaide's 2006 winter was the driest on record. Other features of Adelaide's 2006 rainfall are summarised in Table 1.


GRAPH 1. RAINFALL, ADELAIDE, 2005 and 2006
Graph 1. Rainfall, Adelaide, 2005 and 2006
Source: Bureau of Meteorology, Archive of SA and Adelaide Monthly Climate Summaries


TABLE 1. FEATURES OF ADELAIDE'S RAINFALL, 2005 AND 2006

MONTH
2005
RAINFALL
2006
RAINFALL
AVERAGE RAINFALL
COMMENT FOR 2006

January
37.0
22.4
19.2
February
10.4
15.6
13.6
March
11.6
20.2
25.7
April
3.2
52.4
37.5
Wettest April since 1998
May
8.2
48.8
60.7
June
141.8
12.4
85.2
Driest since 1967
July
42.8
34.2
76.5
June/July period is second driest on record
August
90.8
10.2
69.8
Third driest on record
September
59.2
31.0
64.0
Driest June to September period since 1914
October
88.4
1.0
48.5
Equal driest on record
November
79.6
16.6
32.5
Driest November since 2003

SEASON
Summer
79.4
94.4
60.3
Wettest summer since 2002/03
Autumn
23.0
121.4
123.9
Wettest autumn since 2001
Winter
275.4
58.6
231.5
Driest on record
Spring
227.2
50.2
145.1
Driest first two months since 1914

Source: Bureau of Meteorology, Archive of SA and Adelaide Monthly Climate Summaries


RAINFALL IN PASTORAL AND AGRICULTURAL DISTRICTS


As with the Adelaide metropolitan area, the South Australian pastoral and agricultural districts suffered below average rainfall deficiencies during winter and spring of 2006. Table 2 summarises the 2006 monthly rainfall statistics for these areas.


TABLE 2. RAINFALL IN SOUTH AUSTRALIAN PASTORAL AND AGRICULTURAL DISTRICTS, JANUARY 2006 TO NOVEMBER 2006


MONTH
SA PASTORAL DISTRICTS
SA AGRICULTURAL DISTRICTS

January
Average to above average
Average to above average
February
Ranged from above to near average
Ranged from very much above to near average
March
Ranged from average to below average
Ranged from above average to very much above average
April
Average to above average
Average to above average
May
Ranged from below to very much below average
Below average
June
Below to very much below average
Below to very much below average
July
Above to very much above average
Below to very much below average
August
Below to very much below average
Mostly very much below average
September
Below to very much below average
Below to very much below average. Much of Eyre Peninsula recorded 'lowest on record rainfall'
October
Average to below average
Ranged from below to very much below average
November
Ranged from near average to very much below average
Ranged from average to very much below average

Source: Bureau of Meteorology, Archive of SA and Adelaide Monthly Climate Summaries


SOUTH AUSTRALIAN RESERVOIRS


RESERVOIR LEVELS

The 113.6 gigalitres (GL) of water held in South Australia's main reservoirs at 30 November 2006 was well below (by about 42%) their combined capacity of 197.4 GL. The two largest reservoirs, Mt Bold and South Para, were at 44% and 59% capacity, while Kangaroo Creek was at 32% capacity. At the same time in 2005, South Australia's main reservoirs were only 6% below capacity.

GRAPH 2. RESERVOIR LEVELS AS A PROPORTION BELOW CAPACITY,
South Australia, 30 November 2005 and 30 November 2006
Graph 2. Reservoir levels as a Proportion Below Capacity, SA, 30 November 2005 and 30 November 2006
Source: SA WATER, Reservoir levels


The main South Australian reservoirs supplying water to Adelaide are within the Mount Lofty Ranges region and the weather stations closest to the reservoirs are the Mt Crawford, Mt Barker and Parawa/Myponga weather stations. Rainfalls in the first four months of 2006 were generally above average. From May to November, 2006 monthly rainfalls recorded at these weather stations were generally below average, particularly for the months of August and October (Graph 3). When the entire period January 2006 to November 2006 (inclusive) is considered, all of these stations recorded below-average rainfall totals for the eleven month period; for Mt Barker the total rainfall was 72% of the average for this period, Mt Crawford was 65% and Parawa/Myponga was 78%.

GRAPH 3. DEVIATION FROM AVERAGE MONTHLY RAINFALL,
Main reservoir catchment areas, January 2006 to November 2006
Graph 3. Deviation from Average Monthly Rainfall, Main reservoir catchment areas, January 2006 to November 2006.
Source: Bureau of Meteorology, Daily Weather Observations for South Australia and
Bureau of Meteorology, Climate Averages for Australian Sites - Averages for South Australian Sites


WATER CONSUMPTION

DAILY WATER CONSUMPTION

The average water consumption in the Adelaide metropolitan area for November 2006 was 513 megalitres (ML) per day, which was 22% greater than for November 2005 (421 ML/day). The daily average water consumption for November is 506 ML/day. The total water consumption from July 2006 to November 2006 was 62,931 ML (or 411ML/day) compared with 51,532 ML (337ML/day) for the same period in 2005-06.
Source: SA WATER, Reservoir levels

Graph 4 shows the average daily water consumption per person in the Adelaide Metropolitan area decreasing. Water restrictions were introduced in 2003-04.

GRAPH 4. AVERAGE DAILY WATER CONSUMPTION,
Consumption per person, Adelaide Metropolitan Area , 2000-01 to 2005-06
Graph 4. Average Daily Water Consumption, Consumption per person, Adelaide Metropolitan Area, 2000-01 to 2005-06.
Source: SA WATER, Annual Reports, Operations Overview