HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL NRM North Tasmanian Agricultural Research Forum Mark Hocking Presentation part of the Natural Resources and Ecosystems Services Groundwater and salinity projects - from 2006 today HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL Understanding Groundwater Flow Systems and processes causing salinity in the Northern & Southern Midlands (two projects) AIM: To develop an understanding of the Groundwater Flow Systems (GFS) and processes causing, or likely to cause, salinity within the Midlands FUNDING: LOCATION: NAP region parts of Northern Midlands + parts of Southern Midlands and parts of the Clarence municipalities (12 months) - completed 2006 National Action Plan HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL METHOD: for Northern & Southern Midlands GFS projects Groundwater drilling Hydrogeological characterisation of landscape (GFS units) GFS mapping Developing conceptual models of groundwater flow RESULTS / OUTCOMES / CONCLUSIONS: Conceptual diagrams of salinity processes upon all GFS, Prioritised GFS units across the region for salinity risk, The majority of salinity processes are associated with shallow groundwater, A map layer and tools which can be used for educating salinity processes and the likely distribution across the Midlands. (Understanding GFS continued) HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL Farm Scale Salinity Management Planning AIM: To link the paddock scale land use with paddock and catchment scale water balances and salinity processes FUNDING: LOCATION: Back Creek Catchment (12 months) - completed Improving the understanding of the processes contributing to salinity at the property and catchment level METHOD: Groundwater drilling, Plant water use (APSIM & CAT) & groundwater modelling (Modflow), Soils mapping, Salinity & EM mapping, Landuse change scenario modelling, Farm scale SMPs. National Action Plan HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL RESULTS / OUTCOMES / CONCLUSIONS (Farm Scale SMP continued) The majority of salinity is attributed to groundwater level, Groundwater processes (in the Back Creek catchment) are controlled by local processes, not upward head pressures from the regional aquifer, Salinity on each property is generally caused by on-property landuse, EM surveys are very sensitive to soil moisture & ironstone, little interpretation made, Enhancement/cleaning of surface drains is the most effective measure to reduce surface ponding and shallow groundwater levels in the catchment, Tree plantations (3 rows wide) can lower the watertable up to 200 metres away, Wet harvest crops (eg. broccoli, potatoes, etc.) have a significant impact on the property waterbalance, but negligible on the catchment scale, Catchment groundwater response time is years, farm response time is 2 years Numerous other results / outcomes / conclusions HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL Regional Salinity Data Audit AIMs: Provide a baseline salinity trend for the region Provide direction for monitoring to address RCTs FUNDING: LOCATION: NAP region (12 months) - completed 2008 METHOD:Collating all salinity monitoring data, Attribution of information, spatially & site details Develop salinity monitoring database for NAP region Identify salinity trends and sub catchments National Action Plan HYDRO GEO ENVIRONMENTAL SERVICES HOCKING ET AL (RSDA continued) RESULTS / OUTCOMES / CONCLUSIONS The DPIW surface network needs maturing before trends could be made, Most of the 432 salinity monitoring bores have been established to understand salinity process rather than trends (limiting interpretation of trends), Large investment in infrastructure is required to adequately monitor salinity trend in NAP region Despite the data limitations, the following land & water catchments were identified with increasing trends; Coal-Pittwater & South Esk (saltloads) Macquarie, Little Swanport & Pipers (>5cm groundwater) Jordan & Boobyalla-Tomahawk (