Reconnecting irrigation with the river and ecological function of the catchment CSIRO Sustainable Agriculture Flagship Keith L. Bristow CSIRO Land and Water Townsville, Queensland, Australia

Natural capital - Social/cultural capital - Produced capital It is not about balance – but choices and decisions No ultimate trade-off between the economy and environment Environment Society Economy ($) Built Infrastructure Ecological Infrastructure Complex inter-connected systems

(Area  770 million ha; Population  22 million) “SUPPLY” DEMAND Pressure for protection and ‘sustainable’ use Pressure for repair and ‘sustainable’ use Great Barrier Reef Tropic of Capricorn Brisbane Broome Carnarvon Perth Melbourne Adelaide Darwin Victoria NSW Queensland Northern Territory South Australia Western Australia Tasmania Sydney Townsville Karratha Kununurra Katherine MDB Australia - the big picture 6 7

The MDB ‘Excess demands’ on the environment got the MDB into trouble… Opportunity to re-balance the system… But… Still want to drive the system harder and faster!!

The environment Does not function as a ‘business’! Catchments (ecosystems) reflect water flows – quantity, quality, timing, duration…and a myriad of other processes Complex systems characterised by feedback, non- linearities, lags, trigger and tipping points…. Cautious about applying business/engineering principles; efficiency, growth, factor four improvements, trade offs… Need to maintain or reconnect irrigation with the river and ecological function of the catchment Need better understanding of and investment in the ecological infrastructure (elements, systems, services and the inter-connectivity between these)

Water in the north is already being used - Decisions are about reallocating water to different uses and understanding the implications Groundwater is critical to base flow and maintenance of ecological functions and processes Water quality is as important as quantity; especially in meeting ecological needs Efficiency is not the answer to everything - Need to meet multiple objectives; water, salt, nutrient … All irrigation needs an associated salt management plan Key take home messages from northern Australia

Must set and meet water table targets (both quantity and quality) and adjust management practices to meet targets Water management is an individual and collective responsibility Need policies and management systems that make sense for northern tropical environments (event driven systems) Short term economic gains are easy – it is the long-term sustainability that is the real challenge Key take home messages from northern Australia

Complex interconnected systems InlandCoast RIVER Turbid waters Water spreading Root zone Salt & nutrient balance Salinity Sodicity Rising GW soil type impacts ET Salt water intrusion Irrigation GW depletion Irrigation unsaturated zone Bores ET Rain Leakage to sea Drainage quantity/quality Recharge pits Recharge Recycling Monitoring well runoff SW / GW Interactions Sea Geohydrology and geochemistry impacts Wetlands Upwelling Bores Dependent on the river system Have changed the water and salt balance massively Must set and meet water table targets (quantity and quality) Individual and collective responsibility – MUST EXPORT SALT

Traditional large scale irrigated area ‘Mosaic’ structure Advantages Disadvantages ? Irrigation mosaics / agro-ecology

Profile Catchment Farm enterprise Field State / Region Mechanistic Quantitative Functional Qualitative Scale dependent processes Specialisation Integration Biophysical Socio-economic Country

Whole of system approach - System Harmonisation Definition: A strategy to improve cross-organisational communication and system-wide management to improve production and environmental outcomes in a whole of catchment context (Khan et al., 2008) Integrate science, policy, planning, management and communities... Working at the interfaces …environmental-social- economic…groundwater-surface water… land-ocean… Collaborative and transdisciplinary approaches An ongoing conversation…delivering continual innovation and improvement…

Significant opportunities for improved farm production A and D are representative points on the efficiency frontier for the best technologies at a point in time (▬) C and F are specific points on new efficiency frontiers for new technologies (---) Point B represents a position below the current efficiency frontier use (Keating and Carberry, 2010)

The MDB Need a better long-term ‘engagement’ strategy Australian’s are investing considerable money in the MDB… All are aware tough decisions are involved… Must deliver an environmentally resilient and regenerative system for future generations…

Past technologies A and D are representative points on the efficiency frontier for the best technologies at a point in time (▬) C and F are specific points on new efficiency frontiers for new technologies (---) Point B represents a position below the current efficiency frontier use (Keating and Carberry, 2010)

Investment framework - Production vs investment ($) Pathway 1: Improve the agronomic performance of growers Pathway 2: Encourage growers to adopt risk management practices Pathway 3: Increase efficiencies of resource use Pathway 4: Create new production frontiers Pathway 5: Maintain current production potential Based on John Dillon, An Analysis of Response in Crop and Livestock Production (2nd edition), Pergamon Press, Oxford

Involves integrating academic researchers with non- academic participants to research a common goal and create new knowledge, theory and practices (Strong disciplinary skills working collaboratively with a wide range of stakeholders on complex problems towards a common goal) Transdisciplinary approaches

The environment Biodiversity Ecosystem services Resilience

Irrigation efficiency – a flawed concept Need to be specific about how water used in irrigation The consumed fraction (essentially ET), comprising: -beneficial consumption (for the purpose intended or other beneficial use such as environmental purposes); -non-beneficial consumption such as weeds or resulting from capillary rise during a fallow period); The non-consumed fraction, comprising: -recoverable flows (water flowing to drains and back into the river system for possible diversion downstream, and percolation to freshwater aquifers); -non-recoverable flows (percolations to saline aquifers, outflow to drains that have no downstream diversions or direct outflow to the ocean)

Key drivers ‘Empty’ to ‘full’ world… More with less!! Environment, water, food, energy...population… Complex inter-connected systems Peak oil, peak water, peak… Economic growth model… Competition (‘vested interest’) vs collaboration …….