Salinity Scoping Study

Mid Macquarie Landcare partnered with Little River Landcare to deliver a Salinity Scoping Study for the Department of Climate Change, Energy, the Environment and Water.

Collaborations - LEP23-005-MidMac-06_LLC_001

The issue

There has been no coordinated extension about salinity in the Central West region for approximately 20 years and data capture of the extent of dryland salinity ceased as a governmental priority in 2000.

Following three wet years and a major shift in landuse to widescale cropping a considerable increase has occurred in the number and size of saline sites across the state from Victorian border to Narrabri in NSW, particularly in the cropping belt of slopes and plains. High risk geologies of Ordovician and Silurian Volcanics have shown to have large increases in the number and size of saline sites and a rise in groundwater and stream EC.

The Wellington / Dubbo area is known to have the second most mapped salinity in NSW. So, the Department of Climate Change, Energy, the Environment and Water engaged Mid Macquarie Landcare and Little River Landcare to deliver a Scoping Study looking at past and newly emerging saline sites in the Wellington/Little River region.

The aim of the Scoping Study was:

  • to determine the extent of saline sites in the local landscape and how they are currently being managed and
  • to test how the newly developed ArcSurvey123 app developed by Cibolabs performs as a mechanism for “citizen science” engage with the community, and provide training and extension about salinity.

The solution

TRAINING

Project coordinators, Danielle Littlewood (Mid Macquarie Landcare) and Phoebe Gulliver (Little River Landcare) undertook training in Field Maps and Survey123 site survey data collection applications with Cibo Labs, in addition to site survey training in the field with DCCEEW staff.

ENGAGEMENT

The study was promoted to the community via a combination of:

  • direct emails, 
  • social media,
  • local posters,
  • a media release and
  • targeted engagement based on known past sites.

Interested landholders submitted an Expression of Interest to their local Landcare group and a face-to-face site visit was booked for each property.

The impact

SITE INSPECTIONS

The demand for salinity advice was overwhelming, with “participating landholder places” being filled within 3 hours of Little River Landcare posting about the opportunity on Facebook.

A total of 20 site inspections were undertaken across the Mid Macquarie and Little River Landcare area, with a total of 32 saline sites recorded.

Each site visit was conducted with the landholder, the Landcare Project Coordinator and the DCCEEW Principal Salinity Officer.

The area and photos of the site were mapped. In addition at each site we recorded the current management, relevant HGL, site measurements such as soil/stream EC and pH, salinity symptoms and site observations.

RESULTS

  • New sites – There were 11 newly emerged saline sites that have not been known or recorded previously. The combination of local cropping increase and three wet years has driven this new landscape expression.
  • Vastly expanding sites over time – 12 sites that were known from past engagement had expanded considerably. One site which was mapped in 2000 has expanded from 10sq m to over 30ha. Most sites have at least doubled in size.
  • Well rehabilitated sites – 3 sites were inspected where long term salinity management programs have been undertaken since the early 1990’s and the sites are relatively stable, productive and fitting in well with overall farm management. This is despite the large increase in EC going through the site as a consequence of the wet conditions, One site on a regional fault line had salinities approaching sea water, but site was still stable due to excellent land management over time.
  • Poorly managed – 1 site inspected, which was originally a significant salinity demonstration site, had been degraded well beyond original salinity status due to a change in land ownership and resultant fence, tree and saline pasture removal.
  • Waterlogging only – 1 site was inspected and was a widespread waterlogging issue comprising common rush across extensive areas of paddocks. Although non saline, the area is a concern for grazing as the wet conditions have provided ideal growth conditions resulting almost 100% ground cover of 1m tall rush.

CONCLUSIONS

The Scoping Study found that there is a concerning increase in the extent of land being impacted by salinity (well beyond levels seen in the late 90's), but that in areas where extension resulted in land management changes and that management is being maintained, the impact of the saline outbreaks is being managed.

The use of the new Site Survey 123 app was a success and proved a useful data collection tool, engagement and training tool. Recommended tweaks based on the Landcare site experience were incorporated into the technology to improve its use for future projects.

As a result of this Scoping Study, a recommendation was put forward to the Basin Salinity Program that there needs to be ongoing quantitative data collection to underpin activities and programs targeted at salinity control across landscapes and waterways, as the salinity issue re-emerges, noting that delivery via existing Landcare networks was a successful model for effective, efficient engagement within the local community.

Author: Danielle Littlewood

Key facts

  • Saline sites are expanding at a concerning rate in the Central West
  • A citizen science based extension program could effectively address this issue using knowledge from past experience
  • Landcare is a proven effective delivery mechanism for this type of project

Project Partners