Water use in Tumut Shire, Australia

Indicator: Water use

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What the results tell us for Tumut

Data for water use in 1997–98 and 1998–99 suggest that water use has decreased (Table 1). Very low per capita water consumption (115kl per capita per year) is a function of the Shire being within a high rainfall zone, with consequent low reliance on reticulated water for maintenance of gardens. This is further supported by data from the Stressed Rivers Assessment Reports (DLWC, 1999) which indicates that low extractions from unregulated streams across the Shire, with the exception of the Adelong River (Table 2).

Approximately 66% of Tumut Shire falls within unregulated subcatchments. Not all subcatchments listed in Table 2 lie wholly within the Shire. Subcatchments are of differing size, in terms of area and volume of water flowing through them.

Table 1. Water use in Tumut Shire
Year	Domestic	Commercial	Industrial	Institutional	Public	Unaccounted	Dryland rural	Irrigated rural	Total use
Bore
1997–98	0	0	10	0	0	0	nd	499	499
1998–99	0	0	10	0	0	0	nd	499	499
1999–2000	0	0	0	0	0	0	nd	nd	nd
Surface water
1997–98	0	0	0	0	0	0	nd	nd	nd
1998–99	0	0	0	0	0	0	nd	nd	nd
1999–2000	0	0	0	0	0	0	nd	nd	nd
Reticulated
1997–98	1300	106	260	30	62	151	0	0	1909
1998–99	997	104	638	61	11	nd	0	0	1811
1999–2000	nd	nd		nd	nd	nd	nd	nd	nd

Note: all water use is reported in this table in megalitres; nd=no data.

Table 2. Water extraction in Tumut Shire in unregulated subcatchments
Subcatchment names	Area of Subcatchment (hectares)	% of Subcatchment in the Shire	River Flow (ML/day) - 50 & 80 Percentile Flow Rate		Average Water Extraction - 50 & 80 Percentile Flow as %
Subcatchment names	Area of Subcatchment (hectares)	% of Subcatchment in the Shire	50%	80%	50%	80%
Adelong	29 697	100	nd	nd	40-49.9	80-89.9
Hillas	49 188	100	21	7	10-19.9	30-39.9
Tarcutta	6 428	100	88	38	10-19.9	30-39.9
Goobarragandra	74 300	99.8	255	147	0-9.9	0-9.9
Goodradigbee	109 574	0.2	207	49	0-9.9	0-9.9
Tantangara	46 693	11.2	nd	nd	0-9.9	0-9.9
Bombowlee/Brungle/ Adjungbilly	53 326	99.7	nd	nd	nd	nd
Gilmore/Sandy	30 403	100	nd	nd	nd	nd

Note: there were no data about the number of water extraction licences of the licensed irrigation areas in the Shire; nd=no data.

About the data

Data on the number of water extraction licences, licensed irrigation area, river flow and average water extraction rates in unregulated streams have been collected by the NSW Department of Land and Water Conservation (DLWC) and reported in the Stressed Rivers Assessment Report for the Murrumbidgee catchment: The report was published by the DLWC, in Sydney, 1999. Details about the data sources and assessment process are contained in each of these reports. A brief summary about some of the data follows:

River flow - Flow percentiles are reported for the month of maximum demand. The flows were estimated using information available through DLWC's flow gauging network. For those rivers which don't have local gauging stations on them, a range of hydrologic predictive techniques was used to derive flow estimates.

Average water extraction rates - Estimates of peak monthly water extractions were made using the surface water returns lodged by licence holders. The dataset is incomplete as not all water usage cards are returned to DLWC. Volumes of extraction have been adjusted to account for this.

The Stressed Rivers Assessment Reports provide data on unregulated catchments only. DLWC has defined unregulated streams as "those which do not have major rural dams, primarily for irrigation supply downstream and therefore most water users rely on natural flows for their water supplies" (DLWC, 1999:1). Flows in unregulated streams however, can be and are still affected by town water supply, hydro-electric dams, weirs and other water diversions.

Data have also been collected and maintained by Council.

Description: What does 'water use' measure?

These data are used:

per-capita and total volume of surface and bore water used by each sector (domestic, commercial, industrial, dryland rural and irrigated rural)
number and recharge rates of known bores

Why do we report this indicator?

Water is taken from streams and groundwater for a large number of purposes such as domestic use, agricultural use and industrial uses.

The amount of water used is of concern to State of the Environment reporting because the impact on streamflow can be significant, placing pressure on aquatic ecosystems and limiting the amount of water available for downstream users. The need to ensure adequate flow for aquatic ecosystems is the reason that environmental flow regulations have been enacted in most jurisdictions.

Total water consumption tends to increase as human population increases. This can require the construction of extra water supply reservoirs to meet the increased demand for water, thus placing further pressure on the natural environment. Where this is not possible, it is necessary to investigate alternative sources of water, reduce per capita consumption of water, or to introduce water restrictions, typically the case in the summer months in some areas.

The amount of water used for various sectors should be expressed not only as the relevant totals for each sector, but also as a proportion of the total population (for domestic water use), and as an average volume used for each hectare irrigated for water used to support irrigated agriculture.