Conjunctive management of surface and groundwater in transboundary watercourses: a first assessment J. Lautze (IWMI) B. Holmatov (Twente) D. Saruchera (IUCN) K. Villholth (IWMI)

Introduction Recognition of shared surface water bodies led to establishment of RBOs Transboundary aquifers receiving growing recognition However, institutional frameworks remain separate, despite the interlinkages Institutions for conjunctive management have not received extensive focus

Objectives To understand how transboundary institutions have addressed conjunctive management To assess status and strength of conjunctive water management in transboundary water treaties How to enhance conjunctive water management in transboundary treaties

Methodology Reviewed transboundary treaties to understand their scope and content based on water sources – surface, ground and conjunctive Used formally codified examples of water sharing, found in transboundary treaties Database used: Giordano et al 2014, TFDD, FAOLEX, International Water Law Project, Online searches 266 treaties mined and analysed

Data Analyses 9 quantitative analyses assessing the variance in: -focus of treaties (sw, gw, both) - evolution of conjunctive management treaties (year of establishment) - geographic scale of treaties - treaty focus: water use or water institutions - water allocation - water quality - frequency and nature of basin organizations - Presence of data exchange clauses - Presence of monitoring clauses One qualitative analysis -review of truly conjunctive treaties to understand what sets them apart

Results 80% (209) of treaties focus on surface water 2% (5) of treaties are groundwater oriented 19% (52) of treaties are conjunctive oriented On conjunctive treaties: 39 Light groundwater–heavy surface water coverage 8 Heavy groundwater–heavy surface water coverage 3 Light groundwater–light surface water coverage 2 Heavy groundwater–light surface water coverage

Quantitative Results Water allocation Water quality Data exchange Surface water treaties – 55% Groundwater treaties – 80% Conjunctive treaties – 73% Water quality Surface water treaties – 40% Conjunctive treaties – 80% Data exchange Surface water treaties – 43% Groundwater treaties – 100% Conjunctive treaties – 92%

Qualitative Results From 8 truly conjunctive treaties 2 distinct characteristics of conjunctive treaties emerge: 1) grant similar legal protection to both surface and ground water 2) focus is on the problem-shed, not watershed

Summary A discernible body of conjunctive treaties, more than in groundwater Emphasis of conjunctive treaties is on: data exchange monitoring organizational development Limited focus on specific water uses except for the environment Conjunctive treaties respond to issues (problem shed) rather than watersheds

Lessons for SADC Scale of conjunctive water management treaties is not straightforward. Limited growth of robust conjunctive treaties is likely due to knowledge gaps. Investment in filling this knowledge gap is urgent. Those who genuinely want to implement conjunctive management lack guidance. An opportunity to inform more effective management exist. Simply incorporating groundwater into existing RBOs may not work.

Areas for Further Study When is conjunctive water management necessary? What set of criteria can determine this? Development of global legal guidance on transboundary conjunctive management

Thank You!! Full Paper: Water Policy (2018) 20 (1): 1-20. https://doi.org/10.2166/wp.2018.033 Mail: J.Lautze@cigar.org