Factors affecting seasonal forecast use in Arizona water management: a case study of the 1997-98 El Niño

The 1997-98 El Nio was exceptional, not only because of its magnitude, but also because of the visibility and use of its forecasts. The 3 to 9 mo advance warning of a wet winter with potential flooding in the US Southwest, easily accessible by water management agencies, was unprecedented. Insights about use of this information in operational water management decision processes were developed through a series of semi-structured in-depth interviews with key personnel from a broad array of agencies responsible for emergency management and water supply, with jurisdictions ranging from urban to rural and local to regional. Interviews investigated where information was acquired, how it was interpreted and how it was incorporated into specific decisions and actions. In addition, technical and institutional barriers to forecast use are explored. Study findings emphasize (1) the need for special handling of tailored forecast products on a regional scale, (2) the need for systematic regional forecast evaluation and (3) the potential for climate information to directly affect water management decisions through integrating climate forecasts into water supply outlooks where appropriate.