Introduction: Nutrient Pollution
There are many sources of nutrient pollution in the Russian River, but RRWPC has focused on the Laguna de Santa Rosa, largest tributary to Mark West Creek. (14-miles long and draining 254-square mile watershed encompassing most of the Santa Rosa Plain). Those two water bodies form the largest tributary to the Russian River, joining at the Mirabel confluence. The watercourse and associated wetlands form a major floodplain during winter storms, capable of storing over 80,000 acre-feet of storm water.
The Laguna has numerous water quality impairments, including phosphorus overloads. For the last few years, Regional Board staff worked to develop load allocations for phosphorus polluters including designation of allocation limits to the various contributors. The effects of those loadings can be seen with the prolific growth of Ludwigia, massive algae blooms in Laguna and Russian River of all shapes, sizes, and colors, especially in hot weather when stream flows are very low. The Laguna’s dissolved oxygen problems stem from the over abundance of nutrients. Drought is also playing role in exacerbating this situation.
Santa Rosa’s wastewater discharge permit allows ‘no net discharge’ of phosphorus. The local regulatory agency recently determined that the Laguna and lower Mark West Creek had no remaining assimilative capacity for that nutrient. A strategy was developed by the City of Santa Rosa and the Regional Board to identify nutrient credit trades where environmental clean ups of phosphorus in nearby areas can offset any phosphorus the City may contribute in their discharge.
RRWPC’s major concern has been the contribution of phosphorus by nutrient rich wastewater irrigation runoff, especially in the Rohnert Park area. Thus far, the Regional Board has minimized our concerns, yet it is our major goal to stop runoff from over-irrigated landscapes that discharge nutrient rich runoff into our Impaired Laguna. We support stream setbacks, drip irrigation, and other means to assure that the irrigation goes nowhere but directly on the landscape in agronomic amounts.
Nutrient Reduction Program
NPDES Waste Discharge Permits: Santa Rosa
- RRWPC Addendum #2: Waste Discharge Requirements and Master Reclamation Permit for the City of Santa Rosa, 11-21-2013
- RRWPC ADDENDUM: Waste Discharge Requirements and Master Reclamation Permit for the City of SR Subregional Water Reclamation System, Sonoma County, July 22, 2013
- RRWPC Comments on Waste Discharge Requirements and Master Reclamation Permit for the City of SR Subregional Water Reclamation System, Sonoma County, July 22, 2013
- RRWPC Comments on Waste Discharge Requirements and Master Reclamation Permit for the City of SR Subregional Water Reclamation System, Sonoma County, December 3, 2012
Nutrient Offset Program
- Sonoma County Gazette, April 2013: Nutrient Reduction Programs Currently Center Stage
- RRWPC Letter to Regional Board: Nutrients: July 26, 2012