City of Santa Rosa > Departments > Water > Water Reuse System

Water Reuse System  

Santa Rosa Water operates a Water Reuse System which serves approximately 230,000 residents in Santa Rosa, Rohnert Park, Cotati, Sebastopol, and unincorporated portions of Sonoma County. The hub of the Water Reuse System is the Laguna Wastewater Treatment Plant, which recycles wastewater from homes and businesses throughout the region.

The Laguna Treatment Plant recycles approximately 7 billion gallons of wastewater each year. During dry to normal water years, nearly 100% of the tertiary treated recycled water is beneficially reused.  Santa Rosa’s advanced treated recycled water is produced in compliance with all applicable federal, state and local regulations, safeguarding public health and protecting the Laguna de Santa Rosa watershed.

Santa Rosa's Wastewater Treatment Plant 
4300 Llano Rd,
Santa Rosa CA 95407

Click for Directions to Plant (Google Maps)


 Air Photo of LTP

Water Reuse

Santa Rosa's Water Reuse System is comprised of the Laguna Treatment Plant, the Recycled Water Distribution System, and the Biosolids Distribution System. The water is cleaned and disposed or reused in a practical manner, providing the best use of our water resources.   

 Treatment Plant

 Treatment Plant

The Laguna Treatment Plant is a tertiary-level treatment facility that has a 17.5 million gallon average daily flow. The plant utilizes a 60 KV Power Substation, a 2.2 megawatt UltraViolet Disinfection system and a Co-generation facility with three 900 KW Waukesha lean-burn engines. The facility serves the cities of Santa Rosa, Sebastopol, Cotati, Rohnert Park and the Sonoma County South Park Sanitation District.  READ MORE

 Recycled Water Irrigation

Recycled Water

Water is cleaned at the Laguna Treatment Plant, and pumped through the recycled water distribution system. The system is comprised of 6,130 acres and utilizes 45 pump stations to deliver recycled water.




Biosolids provide nutrients to soil and help it maintain moisture. The Biosolids Compost Facility is an agitated, aerobic, naturally heated, biological process that produces approximately 12,000 cubic yards of compost annually. 


 Otter Natural Resources

Santa Rosa Water staff and the community take great pride in being good stewards of our watershed. The Natural Resource Program aims to balance the use of recycled water to grow food with the need to preserve and promote biodiversity in the Laguna.



Environmental Laboratory

Our recycled water is continually regulated, monitored and tested by the Laguna Environmental Complacence Laboratory, the Environmental Protection Agency, the Regional Water Quality Control Board, and the Department of Public Health. Read More



 Water Reuse Videos