Skip to main content

Natural Areas

The Ecological Response Model for the Cache la Poudre River through Fort Collins

The Ecological Response Model (ERM) was initiated by the City of Fort Collins Natural Areas Department in collaboration with a team of nine scientists to better understand past, present and potential future conditions of the Poudre River through Fort Collins. This effort supports a community-driven quest to manage for an ecologically healthy and resilient Poudre River.

This integrated model was designed to improve our overall understanding of the Poudre River ecosystem and the many factors that influence it and to model the status and trends of its key resources. The ERM can serve as a decision support tool and will contribute to more informed dialogue about the river through both the broad trends presented in the results and in the discipline specific analyses completed within the model. It can help quantify conditions necessary to realize the integrated vision of clean water; vibrant plant and animal communities; and, a river that provides for the economy and the community's lifestyle.



An extensive volume of data was included in the various analyses run for the ERM. The primary input were the hydrology scenarios. For detailed information on data used for the component analyses please refer to Section III of the Report and the associated Appendices. After background analyses for each of the subnodes, probability tables were created in order to build a probability influence diagram. Final results are presented in the Report in bar graphs and the values are presented in the Appendix as well as here.


This project may be further understood by following these case studies. The case studies follow a single question through the model: What is the likely condition for a particular ecological indicator under a particular flow scenario? Thus the case studies are designed to provide a succinct demonstration of calculations related to a single input, river reach, and ecological indicator.