Gerald T. Orlob, a civil engineering professor emeritus at UC Davis whose contributions to computer modeling of water resource systems has significantly affected their management, has been elected to the prestigious National Academy of Engineering. Among the highest professional distinctions accorded engineers, election to the Washington, D.C.-based organization recognizes important contributions to engineering theory and practice. Orlob directed the development of widely used mathematical models for the planning, design and operation of water-resource systems. Various versions of these models are used now by government and consulting agencies to evaluate the environmental impacts of sewage treatment plant discharges, storm water run-off, agricultural drainage and the operation of major water-supply systems such as that in California. The models simulate conditions in water systems such as rivers, estuaries and reservoirs, and allow policy-makers to evaluate the implications of changing environmental conditions. "These tools are part of the tool kits decision-makers use to assess the consequences of certain actions and evaluate alternatives," says Orlob, who remains active as a researcher and consultant and continues to teach and advise graduate students on campus.