Models contribute vitally to ecosystem conservation and restoration decisionmaking. Restoration project planning in the U.S. Army Corps of Engineers (USACE) may proceed rapidly from project conception to feasibility-level design through a series of sequential decisions, which iteratively articulate the federal interest, quantify the benefits and costs of competing management actions, and reduce uncertainty in project outcomes. In this process, numerical tools are applied to purposes as diverse as enhancing understanding of complex ecological processes, comparing alternative management actions, and building trust and buy-in among stakeholders. Owing to the relatively short planning horizon (typically three years) and high complexity of USACE projects (typically large-scale or watershed-scale actions), there is a perception that ecological models cannot be developed during project planning. This technical note addresses this misconception through three mechanisms. First, the ecological model development process is presented along with examples of modeling misconceptions observed in other agencies and management contexts. Second, common uses of ecological models are explicitly mapped to the USACE planning processes, timelines, and milestones. Third, an example of ecological model development and review is presented for an ongoing USACE watershed restoration study in Proctor Creek, Atlanta, Georgia. From these three lines of evidence, we conclude that ecological model development is not only possible in USACE studies, it is integral and complementary to the goals of the agency's planning process. ECOLOGICAL MODEL DEVELOPMENT: Ecological models have a long history of informing both basic research (e.g., Lotka-Volterra models of predator-prey dynamics) and applied conservation and management (e.g., sustainable harvest and endangered species population viability). Unlike modeling in some disciplines, ecological modeling's objective is not always predicting the absolute behavior of a system (i.e., the "truth"), but often increasing understanding of complex system dynamics or comparing the relative merits of management alternatives (Starfield 1997). These broad uses often imply that models are developed for projectspecific needs, and numerous authors have emphasized the critical importance of tailoring models to a given set of needs, questions, hypotheses, and purposes (e.g.,

Ecological models are used throughout the US Army Corps of Engineers (USACE) to inform decisions related to ecosystem restoration, water operations, environmental impact assessment, environmental mitigation, and other topics. Ecological models are typically developed in phases of conceptualization, quantification, evaluation, application, and communication. Evaluation is a process for assessing the technical quality, reliability, and ecological basis of a model and includes techniques such as calibration, verification, validation, and review. In this technical note (TN), we describe an approach for evaluating system quality, which generally includes the computational integrity, numerical accuracy, and programming of a model or modeling system. Methods are presented for avoiding computational errors during development, detecting errors through model testing, and updating models based on review and use. A formal structure is proposed for model test plans and subsequently demonstrated for a hypothetical habitat suitability model. Overall, this TN provides ecological modeling practitioners with a rapid guide for evaluating system quality.