18 paul dalby activity d waterallocationplanning

7/26/2019 18 Paul Dalby ACTIVITY D WaterAllocationPlanning

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Objectives

Learn the Principles of Water Allocation Planning

Background

Regional Profile of the South East region of South Australia

Figure 1. The South East Region of South Australia

Population 64,000

Economy $2.7B per annum, 3.9% of SAs Gross State Product (GSP)1,

Primary Industries Agriculture, forestry and the fishing industry accounting for 20% ofall direct employment compared with a figure of 5% for SA.

1 http://www.waterforgood.sa.gov.au/wp-content/uploads/2011/03/south-east-regional-profile.pdf

6th AWS Chapter 18 Page 1 of 9


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Tourism

600,000 visitors a year

Environmental values Ramsar-listed Bool and Hacks Lagoons and part of the Coorongand Lower Lakes Wetlands

World Heritage-listed Naracoorte Caves

Environmentalcondition

Wetlands once characterised the landscape in the South East, Drainage and land clearance has seen their reduction from 44%

of the South East to less than 6% of their original extent. 10% of these remaining wetlands are intact 77% of remnant wetlands are groundwater dependant

Community values 90% of the regional population identified water as the most

important natural resource in the South East.

Water resources Very few surface water streams or rivers Water is primarily sourced from the ground water system; an

upper unconfined aquifer commonly named the TertiaryLimestone Aquifer and a deeper confined aquifer referred to asthe Tertiary Confined Sand Aquifer.

Approximately 90 per cent of the total groundwater resourceallocated to support economic activity in the South East issourced from the unconfined aquifer.

Drainage 2,515 km of drainage channel

Removes surface water, controlling saline groundwater levelsand improving regional agricultural productivity

Dehydrated remaining wetlands



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Figure 2. The drawdown in water table for the SE region of South Australia between 2004 and

2009.



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Figure 3. Modelled Wetland Vegetation Classes (WVC) were assigned to each of 72 focus

wetlands based on their known plant communities. The WVC models specify a vertical elevation

range for each WVC so the depth and vertical sequence of vegetation in the wetlands could be

predicted. As groundwater levels decline wetlands are progressively lost until 1.5m when no

wetlands remain.

Economy

Employment2

2Source: ABS 2006 Census



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Production

3

Forestry: 128,000 of softwood and 60,000 of blue gum4. The forest industry contributes

28% to the gross regional product ($750,000) coming from the South East annually5

Forestry: The region harvests in excess of 2 million cubic metres of softwood log each

year (This is around 16% of Australias total). The right to harvest the next three forward

rotations of these forests has recently been sold by the state government to a private

buyer.

Wine: 16,000 hectares of vineyard plantings (for wine) worth $365 M wholesale.

Dairy: 330 million litres of milk produced, farm gate value of $115 M

Livestock: production value $370 M

Field crops: production value $200 M

Potatoes: 130,000 tonnes per annum; Value added $125M, 300 full time jobs

Natural Resources Management Act 2004 (Commercial Forestry)6

Amendments were made to the State Government of South Australias Natural Resources

Management Act 2004, to ensure that the use of water by forestry was accounted for.

Under the Act, a new forest water licensing and permit systems recognise the unique

nature of forest water impacts and have been designed to integrate with existing water

licences and permits under the NRM Act.

3http://www.rdalimestonecoast.org.au/index.php/regional/

4http://www.pir.sa.gov.au/forestry/home/forestry_in_south_australia

5

http://www.rdalimestonecoast.org.au/uploads/Information_Update_Forestry_1.pdf6 http://www.waterforgood.sa.gov.au/rivers-reservoirs-aquifers/water-resources-and-forests/nrm-

commercial-forests-bill/



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Task

1. Describe the consequences of doing nothing.

2. Set a new Consumptive Pool (a level of water extraction that is sustainable, inclusive of a

level of uncertainty) that includes forestry water use.

3. Issue new licenses to forestry for their water use.

4. Reduce all allocations so that the total equals the new Consumptive Pool amount.

5. What will be the implications of the new Water Allocation Plan on the regional hydrology,

ecology and economy?6. Can you think of other ways to achieve a sustainable level of water use that is less

disruptive?



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Consumptive Pool

Use the following table to estimate a new Consumptive Pool. Consider the need to take intoaccount the errors in estimating the recharge, and the likely future impact of climate change.

Process 80%

Estimated

Volume (GL)

100%

Estimated

Volume (GL)

120%

Estimated

Volume (GL)

Inflows Recharge 1,004 1,256 1,507

Surface water inflows 14 15 18

Rainfall on surface water

bodies

247 309 371

Total inflows = 1,265 1,580 1,896

Outflows Evaporation from surface

water bodies481 601 721

Discharge from

groundwater springs78 97 116

Discharge from surface

water creeks79 99 119

Total outflows = 638 797 956

Net Recharge Inflowsoutflows = 627 783 940

Allocation Allocate 50% 313.5 391.5 470

Allocate 75% 470.25 587.25 705Allocate 90% 564.3 704.7 846

Disclaimer: These are not official figures of recharge and should be used only for the purposes of

training.



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Existing Users

Under a Natural Resources Management Plan, existing users must get a license based on their

current level of use.

The current licenses are shown in Table 2.

Table 2. Existing Water Licenses for the Unconfined Aquifer in the South East

Volume (GL)Groundwater extraction for irrigation licenses 680

Stock and domestic use licenses 24

TOTAL CONSUMPTIVE POOL 704

Disclaimer: These are not official figures of extraction and should be used only for the purposes of

training.

Under the new Natural Resources Act (Forestry) 2010, the use of water by forestry must be

accounted for in the Water Allocation Plan. The current level of water use in the region is shown inTable 3.

Table 3. Current Water Use for Different Users of the Unconfined Aquifer in the South East

Volume (GL)

Groundwater extraction for irrigation 268

Stock and domestic use 17

Interception of recharge by plantation forestry 199

Direct extraction from plantation forestry 106

CURRENT WATER USE 590

Disclaimer: These are not official figures of water use and should be used only for the purposes of

training.

18 paul dalby activity d waterallocationplanning

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