Executive summary:
Reliable and effective monitoring of water use and availability is essential for the design and implementation of sustainable, equitable, and efficient water management policies; in particular as pressures on water resources grow as a result of climate change, population growth, and socio-economic development. Yet, in almost every area around the world, large gaps exist in infrastructure and capacity to monitor natural and human components of the water cycle. In this paper, we discuss and review the causes and consequences of water monitoring gaps. We show that deficiencies and gaps in the monitoring of water usage and availability arise for a variety of technical, socio-economic, and political reasons, ranging from chronic underfunding of monitoring infrastructures and agencies by governments to direct opposition to and attempts to circumvent data collection by water users. Resulting gaps in knowledge about water usage and availability increase the likelihood that water will be used or allocated in ways that unsustainable and inefficient, with the burden of water risks resulting from poor water management often falling disproportionately on the environment and marginalised user groups. To address these challenges, we argue that there is a fundamental need for governments, donors, and water managers to drastically increase the prioritisation – and financial investment – committed to both collecting water data and enforcing policies around water use. Agencies responsible for monitoring water use and availability must also explore and develop capacity to exploit new approaches to strengthen monitoring within their constrained budgets and capacity, including through use of digital technologies such as satellite remote sensing and IoT, citizen involvement in water data collection and management, and partnerships with private sector. Finally, there is a need for recognition that perfect monitoring will never be feasible or practical in the real world, and, as such, policy design should seek to explicitly embed and consider uncertainties in our ability to monitor water use and availability. This must include efforts to incentivise compliance with water use regulations by users, in particular in the agricultural sector, through a combination of rewards and penalties that are grounded in improved understanding of water user compliance behavior. Only with these innovations will technical advances in water management plans and policies be likely to succeed in their objectives, and societies be able to address growing water risks in the years to come.