About the Pike River Region

The Pike River area incorporates two distinct regions, that of the Pike River Irrigation District and the Pike Mundic Floodplain. The Pike River Irrigation District between Paringa and Lyrup and incorporating Mid Pike, Upper Pike and Lyrup Heights on the Pike River, occupies an area of around 2400 hectares of irrigated land. The Pike Mundic floodplain sits between the Pike River Irrigation district and the River Murray (adjacent to Lock 5) incorporating approximately 4,000ha of floodplain generally ranging in width from 4 to 7km.

European settlement of the River Murray Valley began around the 1840’s, with occupation licences granted in the 1850’s. Up till this time the valley had been largely unmodified by the Aboriginal habitation of the area. The vegetation associations comprising primarily of mallee woodland on the highland areas (more than 25m AHD) and river red gum and black box associations on the floodplain (less than 25m AHD) were intact. Following settlement, land clearance for paddle steamers, the grazing of stock and the construction of Lock 5 in the early 1920’s resulted in changes across the Pike Mundic floodplain. From time to time the water in the Pike River became too

salty for stock to drink and graziers were forced to seek freshwater from alternate sources. This problem was partially alleviated by the construction of banks across Mundic Creek, which provided greater flow into the Pike River.

Irrigation development began in the Pike River Area in the early 1940’s following the increase in the security of water supplied by the Lock & Weir system. However it was not until the 1960’s when private irrigation became established that irrigation development increased significantly in the Pike River area.

The historical development of the Pike area has placed stresses upon the land and water resources of the Pike River in the form of a decline in the health of the  vegetation, biodiversity loss, groundwater mounding, increased salt loads to the River and rising water tables beneath the floodplain itself.

e) Concern over the level of impact occurring in the Pike River area resulted in the Renmark to the Border Local Action Planning Association (RBLAP) helping to establish the Pike River Land Management Group (PRLMG), a non-incorporated community based committee supported by RBLAP. Through the PRLMG, Natural Heritage Trust funding was sought and consultants were engaged in about 1993 to undertake a range of assessments and develop a preliminary Land and Water Management Plan (LWMP). The preliminary Land and Water Management Plan outlined a range of strategies to address issues associated with salt and the environment. These incorporated Salt interception, Education & Change, Disposal, Drainage hazard management, Sustainable future development, Revegetation, Pike and Murray connectivity, and Stormwater strategies. Action in line with these strategies has shown the Pike region to be extremely proactive with over 90% of irrigators participating in efficiency monitoring projects and 85% completing an irrigation management course. Thirteen irrigators have also participated in the Diviner 2000 soil moisture monitoring trials and thirty-one own soil moisture monitoring equipment. Growers have also requested the installation of 86 floating flags across the district, which have been used to monitor perched water tables.

In 2004 the Department of Water Land and Biodiversity Conservation (“DWLBC”) released the Guidelines for Land & Water Management Plans in the SA Murray Darling Basin. These guidelines were developed in recognition of the fact that many LWMPs had been written without a clear framework or guidelines and therefore overall plans lacked a consistent approach. To speed up revision of LWMP the DWLBC identified four Case Study Areas. The Pike Irrigation Area was one such area.

The PRLMG commissioned a consulting company named Australian Water Environments to upgrade the Pike River LWMP in line with the new guidelines. The LWMP document (completed in November 2006) will be used as an investment prospectus to attract funding for the rehabilitation and protection of the area from further degradation.

The upgrade of the LWMP was timely in light of changes in Government policy to address the salinity impact on the River Murray and floodplain management issues driven by the Basin Salinity Management Strategy.

• Effective from the 30th of June 2003 irrigators are required to offset any increases in salinity to the River Murray Prescribed Watercourse. To reflect that some areas will  have a higher salinity impact than others, zones have been created to assist in implementation of the policy. As the Pike River Irrigation Area is within a high salinity impact zone it is very difficult to offset salinity impacts. Without a viable way to offset  salinity no further water can be traded in to increase irrigation development. The LWMP may be able to address this issue through effective strategies including, but not limited to, salt interception schemes.

The complexity of the issues in the Pike River area requires a cooperative approach by stakeholders to address issues affecting the long-term sustainability of irrigation in the region and the long-term sustainability of the natural resources, primarily the Pike Mundic floodplain.

To obtain maximum benefits for each of the stakeholders involved the case study integrates projects such as on-farm drainage management, planning and design of salt interception, DWLBC and South Australian Murray-Darling Basin Natural Resources Management Board (SA MDB NRMB) salinity and water use planning & policy, integrated floodplain management and environmental flows policy and programs, annual reporting, and of course land and water management planning.

Stakeholders involved in the Pike River Case Study includes representatives, when required, from DWLBC, the SA MDB NRMB, and the RBLAP which includes the complete membership of the PRLMG.