Dryland Salinity and Hydrogeology Update & Local Salinity Trends · 2020. 6. 11. · Dryland...

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Dryland Salinity and Hydrogeology Update & Local Salinity Trends

Thursday 28th of March Coomandook

The hydrology information will have particular focus on the Coomandook, Cooke Plains, and

Meningie East localities

Coorong & Districts Soil Conservation Board

• Established under the Soil Conservation Act 1989 with the duty of preparing a District Plan by 1995

• The District Plan was released in 1995 and dryland salinity was seen as the highest priority issue in the Coorong & Districts

• Dryland salinity was the highest priority issue

Regional Implementation Strategy 1995

Following the completion of the South Australian Murray Darling Basin Soil Boards District Plans, dryland salinity was seen as the highest priority issue in the region. This prompted the formation of the Coorong & District LAP and made funding available to produce the first edition of the Local Action Plan and to start implementation.

1995 Soil Board recommendations to address Dryland Salinity

For recharge areas: • Establish Perennial Pastures • Increase crop and pasture water use • Establish fodder shrubs eg tagasate or saltbush • Establish trees • Reduce bare areas caused by wind erosion

For discharge areas: • Establish salt tolerant pastures • Maintain surface cover • Establish salt tolerant trees and shrubs • Fence salt affected areas

The potential area of dryland salinity in the Coorong Districts 1995

Extensive studies in the Coomandook / Cooke Plains area in the early to mid 90’s

Recommendations from these CSIRO and PIRSA Reports

Putting management practices in place within 10 years that will reduce recharge rates across the district by 50% of the 1994 levels will reduce the spread of dryland salinity

Coomandook Landcare Monitoring Network

25 piezometers established in April 1994 Information available on WaterConnect web site Monitoring has been sporadic Comes at a cost

Coorong District Local Action Plan

• The Local Action Plan Committee was formed in November 1995

• First edition of the LAP released in 1997 and focused on dryland salinity

• A second edition of the LAP was released in 2000 and looked at wider NRM issues but dryland salinity was still the highest priority

1997 & 2000 LAP recommendations to address Dryland Salinity

For recharge areas: • Perennial Pastures systems • Increase crop and pasture water use • Establish fodder shrubs eg tagasaste or saltbush • Establish trees

• Alley Farming added to Soil Board recommendations

• Phase cropping added to Soil Board recommendations

• Reduce bare areas caused by wind erosion

For discharge areas: • Establish salt tolerant pastures • Maintain surface cover • Establish salt tolerant trees and shrubs • Fence salt affected areas

Coorong District Local Action Plan

• First edition 1997

• Upgraded in 2000

• Fully re-written in 2011/12

• Public release on April 30th, 2012

2012 LAP - No new recommendations to address Dryland Salinity

For recharge areas: • Establish deep rooted Perennial Pastures

• Increase crop and pasture water use

• Establish fodder shrubs eg tagasaste or saltbush

• Establish trees

• Alley Farming

• Phase cropping

• Reduce bare areas caused by wind erosion

For discharge areas: • Establish salt tolerant pastures

• Maintain surface cover

• Establish salt tolerant trees and shrubs

• Fence salt affected areas

Increase crop and pasture water use

Fodder shrubs

Prevent recharge on bare areas

Revegetation

Shelter Belts

Protect Native Vegetation

Farm Forestry

Discharge Areas

• Puccinellia • Tall Wheat Grass • Saltbush • Distichlis • Balansa Clover, Rye Grass,

Saltwater Couch in mildly saline areas

Salinity Impacts on Public Infrastructure

Salinity Impacts on Farm Infrastructure

1. Rust in vehicles

2. Reduced fencing life

3. Rising groundwater

impact on farm buildings

1 2

3

Recent spread of dryland salinity

• Coomandook / Cooke Plains

• Meningie East

• Colebatch area West of Tintinara

Coomandook / Cooke Plains

Meningie East

SALTLAND REDEMPTION PROJECT SURVEY

Coomandook / Cooke

Plains Meningie East

What new acres have been

affected by dryland salinity

in the last 5 years? 1,610ha 225ha

How much land do you

think is at risk over the

next 5 years? 2,159ha 130ha

How much perennial

pasture do you plan to

establish in the next 5

years?

5,857ha 10,550ha

‘New’ Plants tried locally • Messina

• Salado Lucerne

• Frontier Balansa Clover

• NyPa Forage – Distichlis

Other uses of saline water tried locally • Aquaculture • Desalination for stock water

Messina (Melilotus siculus)

A new legume species to agriculture

Unprecedented waterlogging and salinity tolerance

Teakle et al., 2011

Influence of the Lakes on Groundwater From the Soil Board District Plan 1995

Unconfined Aquifer Water Table

Unconfined Aquifer Salinity

Unconfined Aquifer

Confined Aquifer

Keeping dryland salinity on the radar

• State Dryland Salinity Committee disbanded

• State Dryland Salinity Strategy not to be reviewed

• National Dryland Salinity Program ended

• Dryland salinity is not a priority in the Commonwealth’s Landcare funding program

• Regional NRM Boards are now responsible for dryland salinity

• Need for on-going external funding to address NRM priority issues

• Limited technical support

• Contracted piezometer monitoring