A Systems Approach to Modeling and Impact Assessment in an Urbanizing Watershed

Abstract

Conflicts over water resources reflect multiple viewpoints regarding the value of preserving quality of life, protecting environmental integrity, and the need for continued urban expansion and economic growth. This has led to an increased understanding of the need for systemic and participatory approaches that address resource management from a holistic perspective. Analysis of alternative futures combined with spatially explicit watershed modeling provides a way to scope resource management problems and increase understanding of how current policies, regulations, and practices could play out in the future and impact both watershed-level hydrologic response and water quality. I propose a framework for developing a water quality decision support system (DSS) that embeds the DSS within a larger context of systemic development planning. Under this framework, the natural system is replaced with a series of analytical models and tools are provided for developing and evaluating scenarios.

In this study, a participatory modeling approach is employed to develop such a panning decision support system to assist in managing water quality in an urbanizing watershed in the central Texas Hill Country. The Cypress Creek Project Decision Support System (CCP-DSS) incorporates watershed models with high-quality local data and additional analytical modules allowing for assessment of alternative management strategies. Using the CCP-DSS, I utilize an alternative futures approach to evaluate potential impacts and interactions of continuing urban development, declining aquifer levels, and climate change on water resources in the study area.

This study also quantifies the impact that participation in DSS development had on stakeholders’ perceptions of model legitimacy, buy-in, and consensus regarding priorities for effective management. The need for systemic approaches to water resources planning in central Texas is clear, given the complex nature of the problem. This study demonstrates the utility of a systemic, participatory approach for informing planning and management decisions in an urbanizing watershed.