A Systems Approach to Identifying Hazards in the Management of Stream Buffers for the Protection of Drinking Water Quality

Abstract

In drinking water catchments, exploiting ecosystem services provided by stream buffers has the potential to complement conventional engineering solutions such as water treatment and reduce the overall public health risks to consumers. These stream buffers interrupt the movement of contaminants and sediments from non-point source sources, such as agricultural land, to surface waters. Effectively managing stream buffers can be challenging due to the complexity and diversity of factors that can directly and indirectly impact efficacy. This study uses System Theoretic Process Analysis (STPA) and Early Warning Signal Analysis based on STPA (EWaSAP) methodology to systematically examine the sociotechnical structures for managing stream buffers in surface water catchments using a theoretical scenario representative of typical surface water supplies. The combination of STPA and EWaSAP provides a practical approach for developing requirements for stream buffers in drinking water catchments, focusing on hazard assessment and management measures. The evaluation considers the complex management arrangements for land uses within catchment areas. The performance and effectiveness of these actions can be tracked through the selected sensors and early warning measures. As a practical matter, this approach would help specify requirements for catchment management and drinking water source protection that can be systematically integrated into relevant management strategies.