Self Guided Salinity TourWagga Wagga City Council, the Murrumbidgee Catchment Management Authority and the Wagga Wagga Urban Landcare Group are frequently called on to lead guided tours of urban salinity sites. A self-guided tour booklet illustrating the multi-pronged approach including engineering, revegetation, leakage reduction and community education is available from Council. See the web-based Salt Tour Guide. An overview from this guide is provided here.
1. Wagga Wagga Civic Centre on the floodplain
The Civic Centre was completed in 1999 at a cost of $20 million. The past council building was demolished and the new building is located on the same site. The Historic Council Chambers still stand on the site and now houses the Museum of the Riverina.
Much of Wagga Wagga is situated in a large drainage basin on heavy clay soils with a small catchment discharge point. This prevents groundwater leaving easily. Groundwater levels increase behind this restriction and build up until hey reach the surface causing water logging and salinity.
2. De-watering bores pump station - engineering solution
Location Corner Moorong St and Edward St near low rail fence before Boral Brick’s show room.
Nine deep bores have been installed in the Calvary Hospital area to lower the water table through groundwater pumping. Groundwater salinity levels are closely monitored as it is pumped to the river. Council has a 5 year license from the Dept of Land & Water Conservation to put groundwater into the river. A condition is that groundwater stays below 2 dS/m. What you can see is groundwater flowing into an in-ground tank, via the storm water drain and a pump control station showing litres pumped per second and groundwater salinity level. A de-watering bore interpretation sign provides further information.
3. Emblen Park - demonstration site
Location Island in Hardy Ave at intersection of Hardy Ave & Emblen St
The park was converted from lawn to a salt tolerant plant demonstration site. A de-watering bore is also located here with groundwater pumped to the green tank for watering the park. Community co-operation and consultation was needed to success fully convert the park What you will see is the Calvary Hospital nature strip planting on the way to Emblen Park. A concrete access hole cover is over de-watering bore near cream coloured control box. A de-watering bore control box shows groundwater depth in metres and groundwater salinity level in deciSiemens. Three piezometer covers are evident. Piezometers are drilled to different depths to monitor de-watering bore pumping effects on watertable level.
4. Hardy Ave - alternative streetscape
Location Western end of Hardy Ave below Emblen Park.
A reduction in recharge on nature strips is achieved by planting shrubs and groundcovers to use water and reduce over watering. One aim is to maintain nature strip plant cover in a salty damp environment. Community co-operation and consultation when changing public areas is required. Council nature strip policy may be changed depending on what is learned from this site. What you will see is nature strip mulched and areas paved and replanted with low shrubs and groundcovers.
5. Calvary Hospital area - salt signs
Location Cullen Rd and Meurant Ave.
A de-watering bore green metal control box is located at corner of Cullen Rd and Sullivan Ave. There are some signs of salinity on homes and many homes with no outward signs of salinity. Some homeowners deal with salt in a variety of ways – such as cladding, rendering, and drainage. The watertable began to fall once pumping commenced. A de-watering bore is located in an island at the corner of Emblen Ave and Meurant Ave.
6. Showground - salinity first identified
Location Corner Urana St and Docker St
Wagga Wagga’s groundwater and salinity situation was first identified after trotting track earthworks. Revegetation of the area with existing grasses was unsuccessful due to damp and salt the Showground Society, DLWC and Council worked to manage showground groundwater. The cost of conserving these 2 hectares of land in the Showground was about $300,000 including investigation work, land committed to basin, building evaporation basin, pipe and sub-surface drain installation and ongoing monitoring. What you will see is revegetated inner ovals of the showground trotting track and the use of salt tolerant grasses.
7. Evaporation basin - engineering solution
Location Corner Urana St and Pearson Rd
The issues considered at this site are the safe disposal of saline groundwater as water is no longer able to drain showground water into stormwater system that goes to the river. Disposal of salt that is left after water evaporates from basin is conducted. It may be suitable for industrial use. The evaporation basin has been constructed to prevent leakage into the watertable by finding suitable clay on site and compacting the surface. What you will see is a small earthen dam - evaporation basin. There is an evaporation basin interpretation sign and small trees and shrubs planted along road side of basin.
8. Charles Sturt Uni Sth Campus - discharge area
Location Fernleigh Road
Issues apparent at this site include groundwater and salinity impacts on the sports oval, loss of soil soil structure, and death of vegetation. The salinity impacts on the Juvenile Justice Centre include poor grass cover on the playing fields, and structural deterioration evident on buildings & fencing. There is potential sub-division and housing development on this site now that it has been sold by the state government to local developers. What you will see are salt affected sports oval, road and building damage, erosion of salt affected soil, salt tolerant plants growing on salt affected areas and piezometers to measure groundwater height and salt readings.
9. Leavenworth Dr - vegetation solution
Location - The slopes of Willans Hill above Mt Austin High School
This site shows a major recharge tree planting Leavenworth Drive with interpretation sign. What you will see are interpretation signs, fenced off trees & shrubs. The issues at this site illustrate the difficulty of locating suitable spaces for tree planting sites in urban area, the need for community consultation before planting as once open space is changed to forest. Students from the adjacent school and neighbours have been invited to help plant the site to encourage ownership. Whether the site is a recharge or discharge site affects why, what & where is planted in a catchment. The Environmental Protection Authority funded this planting as part of the Carbon Sink program ($94 000).
10. Willans Hill on Red Hill Rd - recharge area
Location: South end of Missouri Ave
Issues here illustrate how are the geology & soils affect groundwater flow. Tree planting on Willans Hill - a recharge area – has occurred over the years. Watering home gardens affects recharge rates. Housing blocks cut into hills can affect soil water movement & have damp problems unrelated to the regional groundwater system. How do we develop on recharge areas to minimise affects in discharge areas? What you will see at this site are trees planted on hill top and Jubilee Park. Willans Hill divides the catchments of Wagga Wagga and Lake Albert. Tree cover or lack there of is seen on surrounding hills and there is continued expansion of newly developed suburbs.
11. Waterwise Garden, Botanic Gardens - community education
Community education is changing watering habits. A practical demonstration at a home garden scale is developed here. This demonstration garden was one of the first actions taken once salinity identified in the early 1990s. What you will see are interpretation signs, take home information, lawn watering methods and numerous waterwise plants.
We hope you enjoy Wagga Wagga’s salinity tour!