Integrating Hydrology and Ecosystem Functioning in Water Resource Management

The history of water resource management is marked by an engineering-centered paradigm that, in its focus on anthropogenic usefulness through the mechanistic control of flow regimes, has disregarded the fundamental requirements of biological components in aquatic systems. The resulting heritage of siloed water governance has led to widespread ecological degradation: lost hydrological connections, reduced habitat availability, and interrupted nutrient cycles. This paper integrates the current scientific knowledge of ecohydrological processes with the need to connect physical hydrological models with biological indicators of performance. It draws upon an analysis of feedback loops between flow, groundwater baseflow, and ecosystem processes to describe how the non-linear responses of biological communities to hydrological manipulation jeopardize long-term water system resilience. It offers an Integrated Eco-Governance Framework (IEGF) to address these pervasive problems beyond the static approach of allocation frameworks. IEGF builds on three new principles: (1) the introduction of dynamic functional flow regimes that mimic natural hydrologic variability, (2) the establishment of cooperative benefit-sharing arrangements for the co-management of water resources among multiple stakeholders, and (3) the incorporation of adaptive management through real-time, on-the-ground indicators of ecosystem integrity. IEGF aims to transform human relations with water from commodity use to a system management context that honors the functioning ecological system in which water exists. The inclusion of ecological integrity as a primary technical design parameter enables policymakers to balance human needs for water security with ecological demands for essential ecosystem services and resilience to hydrologic perturbations that result from both climate change and human impact.