Description: The objectives of the group are to identify and, where possible repair environmental degradation in the Bombay subcatchment of the Shoalhaven River, and to improve overall land management skills leading to more economically sustainable forms of landuse. Major projects include the rehabilitation of the riparian zone, by fencing the creeks. Other projects have included trialling the treatment of salinity and farm forestry. The Landcare group is now focused on managing riparian weeds across the catchment.
Planting Casuarinas for the Glossy Black Cockatoo Project
In May 2015 Bombay members planted 200 Allocasuarina littoralis seedlings, protected by Corflute tree guards, on “Ridgewood”, Tally Ho Road. The trees, stakes and guards were provided by Greening Australia ACT as part of the regional Glossy Black Cockatoo Project. This project encourages landowners to plant large numbers of suitable casuarina (she-oak) species, the seeds of which are the main food of the endangered Glossy Black Cockatoo. Casuarinas were once plentiful in the region but land clearing and forestry have reduced the birds’ food supply and thus their numbers.
Bombay Drought Recovery: Protecting Land, Water and Biodiversity
The project covered six sites on properties within the Bombay Creek and Little Bombay Creek sub-catchment. Works on Site 1 helped control erosion by rehabilitating a closed access road. Site 2 rehabilitated a salinity site by planting suitable native tubestock. Site 3 decommissioned a failed dam by backfilling and then planting appropriate pasture grasses. Sites 4, 5 and 6 assisted control of feral pig activity on three adjoining properties by monitoring, baiting/trapping, and maintaining fences.
Riparian Zone maintenance and extension on a tributary of Bombay Creek
This project aimed to stabilise a spillway flowing into Bombay Creek by widening to reduce flow velocity, and then to fence and replant a tributary of the Creek.
Riparian Zone Rehabilitation – Bombay Catchment, Part Shoalhaven River 1998 – 1999
The project aimed to regenerate riparian vegetation and wildlife habitat, to curtail creek and riverbank erosion and to improve water quality. This was achieved by fencing to exclude stock, provision of alternative water supplies, natural regeneration and seedling plantings, weed control, and installation of “rock sausages” for bank stabilisation. These works provided vegetated corridors along creeks and river connecting forested ranges to remnant bushland areas, reduced bank erosion, improved water quality and better stock and pasture management.
Methods for stabilising banks were site-specific and included: fencing creek banks to exclude stock; planting native trees and shrubs and allowing natural regeneration of native plants; moving river gravel to redirect flows away from eroding banks; constructing rock sausages on badly eroding bends to prevent further erosion and allow bank stabilisation; and constructing log weirs across creeks to prevent bed erosion and allow banks to be stabilised and revegetated.
Project savings were utilised for development of a coordinated weed management strategy for the protected riparian areas. The strategy included workshops providing information for landholders on mapping, treating and monitoring weeds on their own properties to ensure more effective weed control in the Bombay catchment.
Bombay Landcare Group Farm Forestry Demonstration Project
Farm forestry project in a degraded paddock adjacent to Bombay Creek. Paddock suffers from water logging, salinity, and contains severely compacted soils. The project aims to trial Cypress lusitanica as viable farm forestry timber in a region of medium rainfall and cold winter temperatures.
Riparian Zone Extension – Bombay and Little Bombay Creeks 1997 – 1998
The project was a continuation of the successful riparian management and rehabilitation project conducted on the Bombay and Little Bombay Creeks in the 1992/1993 financial year. The aim of the project was to fence off a further 2.5 km section of the creeks, build dams for alternative stock water, and plant riparian tree species in the fenced off areas. On completion of this stage, it was planned to seek further funding for major structural works to stabilise creek banks.
Bombay Salt Action project
Regeneration of salt scald at “Nunlef” (Jinglemoney Lane) through revegetation. Thirteen piezometers were placed throughout the Bombay area, including three at “Nunlef”. Water levels and electrical conductivities were monitored and analysed. Trees were planted and fenced, the sites have been continually monitored and results included in the regional database.
Lime and Lime Substitute Trial on Two Acid Bombay Soils 1994 – 1999
The objective of the project was to compare the effects of lime and several lime substitutes with and without superphosphate on the growth of lucerne and subterranean clover and on the pH of surface soil. Two sites were chosen, at each of which six treatments were applied: lime at 2.5t/ha, lime at 5t/ha, sewage ash at 5t/ha, N-Viro soil at 7.5t/ha, earth worm castings at 5t/ha and a control. Each treatment was replicated twice. The main plots were subdivided into two x 1m square plots, to one of which superphosphate was applied at 500 kg/ha.
Bombay Salinity Reclamation demonstration
The project aimed to demonstrate how an incipient salinity problem can be recognised and treated before developing into major salt scalding and erosion. This work was in the discharge area because the upper catchment (recharge) was timbered and the middle catchment sown to perennial pasture. Following topographical and electromagnetic induction (EM) surveys, six piezometers were installed to allow monitoring of water and salt levels. A discharge area was fenced, the salt scald itself seeded to salt tolerant grass and clover species, and mulched with straw. Trees and shrubs were planted in the surrounds. Surface drainage was improved by installing a road culvert.
Riparian Zone Management of Bombay Creek
The project involved a demonstration of streambank erosion management techniques. The aim was to develop and execute a plan which combined riparian zone management and streambank erosion control to combat the degradation of Bombay Creek. The project had three phases. Phase 1: Resource inventory and planning. Phase 2: Fencing off the creek. Phase 3: Tree planting and weed control.
Fertiliser Experiment 1992 – 1992
On two contrasting soils the aim of this non-funded project was to compare several recognised fertilizers with sewage ash and neomin, a crushed rock additive. Two replications of six treatments were applied. The treatments were: Groplus, superphosphate, sewage ash, Calphos, neomin and a control. Sub-clover was used as the test crop to avoid any problem due to nitrogen deficiency.