Articles | Volume 19, issue 2
Hydrol. Earth Syst. Sci., 19, 675–689, 2015
Hydrol. Earth Syst. Sci., 19, 675–689, 2015

Research article 03 Feb 2015

Research article | 03 Feb 2015

Protecting environmental flows through enhanced water licensing and water markets

T. Erfani1,2,*, O. Binions2,*, and J. J. Harou1,2 T. Erfani et al.
  • 1School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester, M13 9PL, UK
  • 2Department of Civil, Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT, UK
  • *These authors contributed equally to this work.

Abstract. To enable economically efficient future adaptation to water scarcity some countries are revising water management institutions such as water rights or licensing systems to more effectively protect ecosystems and their services. However, allocating more flow to the environment can mean less abstraction for economic production, or the inability to accommodate new entrants (diverters). Modern licensing arrangements should simultaneously enhance environmental flows and protect water abstractors who depend on water. Making new licensing regimes compatible with tradable water rights is an important component of water allocation reform. Regulated water markets can help decrease the societal cost of water scarcity whilst enforcing environmental and/or social protections. In this article we simulate water markets under a regime of fixed volumetric water abstraction licenses with fixed minimum flows or under a scalable water license regime (using water "shares") with dynamic environmental minimum flows. Shares allow adapting allocations to available water and dynamic environmental minimum flows vary as a function of ecological requirements. We investigate how a short-term spot market manifests within each licensing regime. We use a river-basin-scale hydroeconomic agent model that represents individual abstractors and can simulate a spot market under both licensing regimes. We apply this model to the Great Ouse River basin in eastern England with public water supply, agricultural, energy and industrial water-using agents. Results show the proposed shares with dynamic environmental flow licensing system protects river flows more effectively than the current static minimum flow requirements during a dry historical year, but that the total opportunity cost to water abstractors of the environmental gains is a 10–15% loss in economic benefits.

Short summary
This paper simulates river basin water markets under two licensing regimes: fixed volumetric allowances and scalable licensing with dynamic environmental minimum flow requirements. The model is applied to the Great Ouse River basin in eastern England, with each water user from four main sectors represented individually. The results suggest that the scalable licensing system is more effective in protecting environmental flows, at the opportunity cost of 10-15% of economic benefits to water users.