Abstract
The paper analyzes the problem of collective water management in Spain. The paper has two main objectives: first it provides a brief introduction on long established traditions for collective water management under Water User Associations (WUAs), some dating back to the twelfth century. It discusses the legislative and institutional frameworks that have favored collective water management. The second objective is an analysis at a more specific level, by focusing on the particular case of groundwater as a traditional common pool resource and the problem of mutually beneficial collective action (MBCA). It does so by applying the Institutional Development Framework and an in depth analysis of key factors leading to MBCA. A comparative case study approach is applied to three main aquifers in the central Mancha region. It points to the importance that WUAS can play in facilitating factors that encourage collective action. It also highlights the relevance of social capital as trust between WUAs and the administration, like Water Authorities. It concludes that while solutions like subsidies and payments can help mitigate aquifer overuse, these are not a long-term or sustainable option (economically or sustainably). Only sound institutional design of Water User organizations can favor self-governance and management by farmers.