Coos Watershed Real-time Hydrological and Meteorological Monitoring 2021-2023

The Coos Watershed, located on the Southern Oregon Coast, is the home of an important population of the ESA listed coastal coho salmon. The ESA Recovery plan for the Oregon Coast coho salmon (NOAA 2016) cites the need for increased quantity and quality of freshwater and estuarine rearing habitat. Historically, the need for hydrological and meteorological data was identified in the IMST’s Recovery of Wild Salmonids in Western Oregon Lowlands (2002), and in OWEB’s Monitoring Strategy for the Oregon Plan for Salmon and Watersheds (2003). NOAA’s A Strategic Plan for Enhanced Coastal Observational System and Predictive Hydrodynamic Model for Improved Management of the Coos Bay Estuary, Oregon (2005) ranked continuing gaging station operations as the highest priority. More recently, Oregons 2017 Integrated Water Resources Strategy (OWRD 2017) recommends that the state

continue to maintain the stream gage network, collaborate with other groups, and promote continuous monitoring of changing climates. The lack of long-term hydrological data has driven the Coos Watershed Association (CoosWA) to meet this need.



OWEB funds, along with other matching funds, have been used for staff to operate, and maintain six real-time stream gaging stations. Hydrological data have been analyzed and summarized by water year and reported quarterly and annually on the CoosWA website. Discharge data will be further complied into the long-term data set, flow duration estimates will re-calculated with the updated data. Meteorological data will be summarized by water year. Instantaneous data is available in real-time on our website.



Since 2002, CoosWA has partnered with OWEB, OWRD, ODEQ, NOAA, U of O, CB/NB Water Board, SSNERR, CTCLUSI, Coquille Indian Tribe, BLM and the Coos Basin Partnership (CBP) to support a Water Resources Program that will develop a data set large enough to perform meaningful statistical analysis for monitoring, assessment, research, project effectiveness, and restoration project needs.

The objectives of this project are to continue to collect stream discharge data at six existing sites with the goal of establishing a long term data set which will be used for baseline data and statistical analysis of status and trends. Monitoring stream flows can be used to establish and/or protect water rights for salmonids. Stream flow data can also be used to design salmonid restoration projects. Wood placement projects need to be designed to withstand expected peak flows. We have recently used our stream flow data to model fish passage at a fish impediment (East Fork Millicoma Oxbow Reconnection Project). High quality stream flow data can help to design fish friendlier tide gates and successful tidal restoration projects.

Another objective is to continue collecting our water quality information at our existing hydrological monitoring network. We will continue to collect turbidity and stream temperature at our existing sites. This information can be used to assess the suitability of water quality for salmonids. Collection of continuous water quality parameters at existing gaging stations can be used for water quality load duration calculations that can be used to identify water quality concerns. Collecting water quality information can be used to monitor salmonid restoration project effectiveness, particularly road improvements, and validate/calibrate our work with the Geomorphic Road Analysis Inventory Package (GRAIP). Water quality data can also be used to prioritize areas that are in need salmonid habitat restoration.