Regional Surface Water Supply Project


The RSWSP is a collaborative effort that will provide water from the Tuolumne River via an existing set of perforated pipelines installed in gravel about 8-feet below the bottom of the river bed (located just west of the Geer Road Bridge), a new intake structure and raw water pump station and pipeline. The raw water from the pipelines will be treated at a new water treatment plant to drinking water standards, and delivered to SRWA service areas for municipal and industrial uses. Construction of the local facilities required in each City to integrate this new supply source into their system will be the responsibility of each City. TID will also use the raw water facilities to deliver irrigation water to agricultural users.

The SRWA’s Regional Surface Water Supply Project will deliver a long-term, sustainable water source that will allow for integrated use of groundwater and surface water, and diversify the water supply portfolios for both Ceres and Turlock.

The wet well element of the raw water pump station was constructed using a traditional, Design-Bid-Build contracting method. The construction of the wet well began in 2018 and was completed in early 2020.

The remainder of the Project will be constructed using a Design-Build model. As the name implies, this type of contract is used when both design and construction take place simultaneously throughout the length of the contract. Design-Build projects are typically completed sooner and more efficiently with fewer construction change orders.

The Project will be made up of multiple components including a regional water treatment facility, raw water pipeline, and treated water transmission mains for both Ceres and Turlock.

The schematic below depicts the water treatment process at the Regional Water Treatment Plant. Water is drawn from the Tuolumne River through perforated pipes in the riverbed and pumped to the Regional Water Treatment Plant. Large particles in the water are removed via the flocculation and sedimentation processes. The water is disinfected using ozone gas and then filtered to remove smaller particles remaining in the water. After treatment, water is stored onsite in a concrete tank where chlorine is added for disinfection before the water is pumped to the Cities of Ceres and Turlock for use.

Process Flow Graphic
Process Flow Graphic

Project Benefits

The benefits for residents, businesses, agriculture, and government agencies include:

  • Diverse water supply portfolios
  • Reliable integrated surface water and groundwater systems
  • Drought resilient water supplies
  • Reliable water quality
  • Groundwater aquifer replenishment (as a result of reduced urban groundwater pumping)
  • Benefits to the agricultural community associated with reduced urban groundwater pumping, and the delivery of “offset” water to Turlock Irrigation District (from recycled or other water sources) during dry periods
  • Increased flows in the Upper Tuolumne River to benefit salmon and other aquatic species
  • Potential to provide treated surface water supply to disadvantaged communities and other regional partners
  • Decrease in hardness and mineral content in both delivered drinking water and in wastewater effluent discharges

Media Coverage

Project Schedule

Environmental Process – 2016-2019
Project Design 2018 – 2021
Project Construction – 2021-2023

SRWA Stanislaus Regional Water Authority Project Schedule

Social Media

Follow the Stanislaus Regional Water Authority on Facebook, Twitter and Instagram.

twitter icon Twitter

facebook icon Facebook

instagram icon Instagram

Social Media Policy

SRWA has the right to delete any inappropriate content from its social media pages, including but not limited to: profanity, irrelevant content, redundant content, hateful content, malicious content, uncivil or disrespectful content, attacks or complaints against an individual, financial solicitations, endorsements of a political candidate or party.