Lake Murray to Sweetwater Reservoir Pipeline 3 Relining Project


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An excavator breaks up a section of old pipe

Hot Off the Press

The project reached a major milestone recently with 50 percent of the project's liners installed - that's more than two miles of steel liners! CBS 8's Shawn Styles visited Portals 10 and 12 and compiled this story, explaining the work that is occurring above and below the ground in La Mesa and Spring Valley. 

Portal 18 work in Sweetwater Summit Regional Park is now underway. Click here for a map of the temporary trail detours and closures. 

Work is continuing at a strong pace and the project is on schedule to be complete this summer. Please scroll down to the map section for an interactive map as well as individual maps of each portal. For questions about the project, please call (877) 682-9283, ext. 7005, or check the project's Frequently Asked Questions resource.


The Water Authority began work in September 2017 to reline a regional wholesale water pipeline, which will extend its service life by 75 years or more. The pipeline traverses the western portion of San Diego County from the Riverside County border to Sweetwater Reservoir. The section of pipeline to be relined extends from Lake Murray in the north to Sweetwater Reservoir in the south. It serves the Helix Water District and Sweetwater Authority and traverses portions of Baltimore Drive and Spring Street in La Mesa and the unincorporated communities of Spring Valley and La Presa. A total of 4.3 miles of pipeline will be relined. Construction completion is scheduled for summer 2018.

Schedule and work hours:

  • Fall 2017 through Summer 2018
  • Monday through Saturday, 7 a.m. to 7 p.m.
  • Some nighttime work will occur

For an overview of the relining process, watch this video:

Water-Authority-Pipeline-Relining-Process from San Diego County Water Authority on Vimeo.

About This Project

The project will rehabilitate approximately 22,800 feet of 66-inch and 69-inch diameter pipe. Construction crews will conduct most of the work underground, inside the pipe. They will access the pipe by excavating, establishing, and entering the pipeline through access sites, or portals. Portals 4, 6, 7, 9, and 11 have been repurposed to serve primarily as pipeline access and staging areas for construction equipment and materials. Most construction activities will occur at the remaining portals, which will be spaced approximately 525 to 2,500 feet apart. Existing pipeline access structures will also be rehabilitated as part of the project. The portals will be 25-foot-by-60-foot excavated areas.

Much of the construction work associated with the project will be located within public street rights-of-way, where the existing pipeline is located. Lane closures will occur in roadways along portions of the alignment during construction. Work at a limited number of locations may be conducted during nighttime hours to minimize impacts to the community. Where portals are located in the vicinity of residences, large wooden sound walls will be temporarily placed to ease noise impacts to residents.


Upon completion of this project, the Water Authority will have rehabilitated approximately over half of the existing 82.5 miles of Pre-Stressed Concrete Cylinder Pipe (PCCP). For information on PCCP and the Water Authority’s relining program, please visit

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Project design began COMPLETE
Project design ended COMPLETE
Construction began September 2017
Construction anticipated to end Summer 2018

*All dates are approximate and subject to change.

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Click the map to go to an interactive map to view work locations.


Portal map
Portal map
(View Larger)

Pipeline relining is conducted in several phases.  Primary construction activities will occur at access portals, which will be spaced approximately 525 to 2,500 feet apart.  The portals are developed by removing 40 feet of existing pipe to gain access to the interior of the pipeline and install relining materials.  Not all portals are active at the same time.  Work will shift from one portal to another depending on which phase is under way.

 Much of the construction work associated with the project will be located within public street rights-of-way in the city of La Mesa, underneath Baltimore Drive (south of the Laport Street-El Paso Street intersection), Nebo Drive (to University Avenue), and Spring Street.  Work will extend to some unincorporated areas south of the city. Some portals within the unincorporated portion of the alignment will be located outside of roadways in undeveloped areas.

Click the portal numbers below to open a pdf map of the location for that portal.

                South of Blue Lake Drive and west of Baltimore Drive

Portal 1            Near Baltimore Drive and El Paso Street

Portal 2            Near Baltimore Drive and Bertro Drive

Portal 3            Baltimore Drive between Lake Murray Boulevard and Aztec Drive

Portal 4            Between Alvarado Road and Interstate 8 (portal has been repurposed)

Portal 5            Between Alvarado Road and Baltimore Drive

Portal 6            North of Baltimore Drive and El Cajon Boulevard (portal has been repurposed)

Portal 7            Southwest of Baltimore Drive and El Cajon Boulevard (will go unused)

Portal 8            Between El Cajon Boulevard and University Avenue

Portal 9            Near University Avenue and Spring Street (portal has been repurposed)

Portal 10          Near Spring Street and Finley Avenue

Portal 11          Near Spring Street Trolley Station (portal has been repurposed)

Portal 12          Between Fairway Drive and Polaris Drive

Portal 13          Between Golf Drive and Bentley Place

Portal 14          Between Hartzel Drive and Valley View Lane

Portal 15          Near Vista del Oro Way

Portal 16          Near Helix Street and Margaret Court

Portal 17          Between Arran Avenue and Lakeview Avenue

Portal 18          South of Sweetwater Dam near Sweetwater Summit Regional Park



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The portal area is graded and prepared for excavation.

Overview of portal area with sound walls and fencing installed.

Pipe is excavated and broken in preparation for removal.

Large diameter pipe is delivered to the site on large flatbed trucks.

Welders fuse the pipe together inside the trench.

Each segment of pipe is welded together, forming the new pipeline.

Large trucks mix the grout onsite in preparation for securing the new pipe to the existing pipe.

Grout is delivered into the trench using a scaffolding system.

A final section of pipe is put into place.

The entire pipe is encased in concrete and rebar prior to refilling the portal.

Interior of the pipe after the mortar lining is completed; it is now ready for disinfection and water flow.


Pipeline Relining Overview Video

This video below provides an overview of the San Diego County Water Authority’s Pipeline Relining Program.

News Stories About Pipeline Relining Projects

This video summarizes a recently completed project near Mission Trails Regional Park.

News Stories About Urgent Carbon Fiber Repair Projects

This news story describes an Urgent Carbon Fiber Repair Project conducted in Fallbrook, California.



Click lower right corner of graphic for full screen mode.


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Community Presentations & Events
The Water Authority is committed to keeping residents, elected officials, other government and water agencies, businesses, schools, community groups and organizations in the project areas informed about the project. Water Authority staff shared project information at open house and business events and will be providing additional information or presentations to stakeholders as the project moves forward.
December 22, 2017: La Mesa Farmers Market
October 24, 2017: La Mesa Lions
October 13, 2017: La Mesa Farmers Market
September 27, 2017: La Mesa Chamber of Commerce Breakfast
September 26, 2017: East County Chamber of Commerce
August 8, 2017: City of La Mesa City Council Meeting
May 9, 2017: City of La Mesa City Council Meeting
April 27, 2017: La Mesa Chamber of Commerce Spring Fling Business Expo
February 1, 2017: Helix Water District Board of Directors Meeting
October 11, 2016: Spring Valley Community Planning Group


Project Communications & Open House Events:
Construction Notice - Mailer (South of SR-94)
Portal 8 Construction Notice - Doorhanger
Construction Notice - Mailer
Construction Notice - Doorhanger
Open House Postcard
September 14, 2017: Portal 3 Tent Event
September 7, 2017: Portals 1 & 2 Tent Event

December 15, 2016: Spring Valley Library
December 14, 2016: Nan Couts Cottage @ La Mesa Community Center

On Tuesday, May 16, 2017, neighbors may have noticed Water Authority and other passenger vehicles visiting Water Authority structures and planned project sites. The vehicles spent approximately 10 minutes at each location. This was part of a pre-bid site visit for potential contractors interested in bidding and working on the project. This was NOT the beginning of construction work, which is scheduled to begin this fall.

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The project belongs to a class of projects which have been determined by the State Secretary for Resources not to have a significant effect on the environment and are, therefore, declared to be categorically exempt from the provisions of CEQA; specifically from the requirement for the preparation of environmental documents. The project fits the definition of Class 1 Existing Facilities (CEQA §15301), which is the repair, maintenance, and minor alteration of existing public structures, facilities, mechanical equipment and topographic features involving no or negligible expansion of existing use.


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For more information, please call the 24-hour toll-free project information line at (877) 682-9283, ext. 7005 or email A representative from the project team will return your call within one business day.


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