The Online Watershed Library (OWL) is a service provided by the Center for Watershed Protection that allows ready access to Center publications and other resources (research papers, tools, and stormwater manuals, among others) that support best practices in watershed and stormwater management. OWL is a searchable, online database of basic information, stormwater and watershed manuals and plans, assessment tools, regulatory information, and other watershed-related resources. Users may also submit materials for inclusion in the OWL.

OWL was developed to be a time-saver for watershed and stormwater practitioners as it provides users access to a well-organized database of relevant and up-to-date information. Due to copyright protection, not all publications included in OWL are available for download and in such circumstances, a link to the publication is provided.