Interlake Tunnel - Monterey and San Luis Obispo Counties, California
This page provides a brief overview of the history, timeline of events, EIR Development, contract documents and county presentations for the proposed Interlake Tunnel.
The primary purpose of the Interlake Tunnel was to redirect water from the Nacimiento Reservoir to the San Antonio Reservoir in efforts to reduce spillage at the Nacimiento Dam. Based on historical data, the Nacimiento River basin produces roughly three times the average flow of the San Antonio River basin. To increase the overall capacity of the system, the Interlake Tunnel could capture high Nacimiento River flows and reroute them to the San Antonio Reservoir.
The Monterey County Water Resources Agency (MCWRA) prioritized the completion of the Salinas Valley Water Project (SVWP) and the Salinas River Diversion Facility before the Interlake Tunnel Project.
The tunnel is designed to be approximately 11,000 feet long and used gravity flow dynamics that has an inflow situated at the Nacimiento Reservoir and an outflow built in the San Antonio Reservoir. The total project is estimated to cost $50 million and could be completed by 2022.
The Monterey County Water Resources Agency (MCWRA) expressed priority in a preliminary environmental review before moving beyond pre-construction tasks. Pre-construction costs are imaged here.
Timeline of Events
In June 2014, the Board of Supervisors of the Monterey County Water Resources Agency (MCWRA) authorized negotiation and execution of a funding agreement between Monterey County and the MCWRA for an amount not to exceed $500,000 for program management, engineering and environmental review of the Interlake Tunnel, said funds to be reimbursed to Monterey County if the Interlake Tunnel is approved and financed; and directed staff to return to the Board of Supervisors in July 2014 with a project status report and information on financial impact to the County in regards to funding the agreement. Presentation slides for this meeting are found here.
On August 25, 2014, the Board of the MCWRA hosted a public information session to provide an update for the Interlake Tunnel project. The agenda and presentation slides for this workshop are found here.
On November 19, 2014, the Board of the MCWRA hosted a public information session to provide an update for the Interlake Tunnel project. The agenda, including technical memoradum, and presentation slides for this workshop are found here.
On March 13, 2015, MCWRA published an UPDATED Informational Notice of pending RFP’s for engineering design. This notice contains the RFP schedule.
On April 16, 2015, a RFP pre-proposal meeting was held. The presentation can be found here.
On April 28, 2016, a Notice of Preparation/Initial Study (NOP/IS) was distributed, initiating a 45-day scoping period for the Environmental Impact Report. The NOP/IS can be found here.
On May 16 and 17, 2016, scoping meetings were held. The presentation can be found here.
- Water Resources Agency Agreement for Services
- Water Resources Agency Professional Services Agreement with Surveyors, Architects, Engineers or Design Professionals
- June 3, 2014
- August 25, 2014
- November 19, 2014
- February 26, 2015
- April 16, 2015
- July 14, 2016
- September 15, 2017
- September 15, 2017 Q&A
- May 10, 2018
- July 6, 2018
- Monterey County Water Resources Agency MCWRA: Interlake Tunnel Updated 2020.
- Monterey County Water Resources Agency (MCWRA)
- Salinas Valley Water Project (SVWP)
- Salinas River Diversion Facility (SRDF)
- Salinas River
- Nacimiento River
- Salinas Valley Seawater Intrusion
- Monterey County
- San Luis Obispo County
- San Clemente Dam
- San Antonio Dam
- Interlake Tunnel
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