Omochumne Hartnell Water District (OHWD) Off Season Irrigation Groundwater Monitoring Study

Cosumnes Coalition is collaborating with OHWD, Larry Walker and Associates, UC Water, iWEST/Sac State, The Nature Conservancy, the Water Forum, and the Sacramento County Water Agency to monitor groundwater movement in real time during OHWD's groundwater recharge efforts, as well as perform chemical analysis, in 2018/2019. 


Watershed Assessment

The Cosumnes Coalition completed the 2016 Cosumnes River Watershed Update and Stewardship Plan (2016 Plan), which builds on the extensive conservation and stewardship investment made by a variety of agencies and organizations in the upper and lower watersheds, linking upper and lower watershed approaches in one document.  Click here to open the 2016 Plan.


Water Quality Monitoring Program

The ARC Cosumnes River Monitoring Program is CEDEN compliant and approved by Water Resources.  The Program is made possible by the Cosumnes Coalition contributors and Citizen Scientist volunteers, whose generous donations and dedicated efforts make it possible to gather and analyze water quality data, identify trends, and monitor project outcomes.  The Program was transitioned from Trout Unlimited to ARC in 2017, to support project implementation.

Clickhere for 2015 Monitoring Report

Clickhere for 2016 Monitoring Report

Click here for 2017 Monitoring Report


Cosumnes Coalition

Cosumnes Coalition Partners and Collaborators work together to obtain and share current scientific information to guide restoration, reconciliation and stewardship efforts.  A comprehensive science program includes consideration of water quality, hydrology, groundwater (geohydrology), water supply, land use, cultural resources, economy, connectivity, and ecosystems.  Understanding of each element and how they interact is necessary to support adaptive management decisions, leading to a healthy watershed that can support both humans and native ecosystems.

Salmon Escapement Monitoring

The Fishery Foundation has monitored Cosumnes salmon escapement and out migration for over a decade, creating an important record that may be correlated with weather and passage barrier removal.  USFWS has provided important support of Fishery Foundation monitoring in 2018.


Oneto Denier Flood Plain Restoration

Photo Courtesy of

The Nature Conservancy

Cosumnes 1, 2 and 3:  UC Davis Center for Watershed Science and the Cosumnes Preserve Partners

UC Davis (and more recently UC Merced and UC Water) have worked with the Cosumnes Preserve Partners  for many years to study hydrogeomorphic conditions and aquatic biology of the Lower Cosumnes River.  The work has included: upper watershed hydrologic modeling; lower watershed groundwater hydrology; geomorphology of the floodplain; biogeochemistry and nutrient cycling in aquatic and floodplain habitats; ecology of fish and aquatic invertebrate communities, riparian bird surveys; and analysis of the reestablishment of riparian forests, among other topics.  More information may be found at:

watershed.ucdavis.edu/project/crg1

watershed.ucdavis.edu/project/crg2

watershed.ucdavis.edu/project/crg3

Cosumnes Preserve Partners' history, assessments and plan may be found at:

www.cosumnes.org