Sewer & Water Improvements in SLO

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Current Projects

We are currently installing monitoring wells throughout the City on South Higuera Street from Los Osos Valley Road to High Street to help track the condition of the City’s groundwater.

Future Work

We anticipate starting sewer line replacement work on Chorro, Islay, Santa Rosa, and Leff Streets as well as California Boulevard later this fall.

We're upgrading vital groundwork to enhance the reliability, capacity, and safety of our water and sewer systems in San Luis Obispo.

These projects are not just about replacing aging pipes; they're investments in a resilient, efficient, and sustainable future for our community. Here's how we're improving key services for our residents, businesses, and public spaces:

Timeline & Objectives
What to Expect During Construction
Contact Us

Construction for each area is expected to take 4-6 months.

Upcoming Projects

The 2026 Sewer & Water Projects are primarily focused on replacing aging sewer pipes and waterlines in certain areas of San Luis Obispo (see the map below) to ensure reliable, efficient service for the community, but they also present opportunities to support key City goals such as sustainability, capacity enhancements, and minimizing future maintenance costs.

Islay Sewer Replacement
California Waterline Replacement

[Map]

Quick Facts: Sewer & Water Infrastructure Replacement

These projects upgrade underground sewer and water pipes to improve reliability, capacity, and safety.
Work involves excavating trenches along roadways to replace aging underground lines.
Projects focus on utilities only and usually do not include full street resurfacing.
Construction zones may have open trenches, dirt piles, and heavy equipment like excavators and loaders.
Steel plates may temporarily cover trenches when work is paused.
Traffic control measures such as cones, barriers, and signage help guide vehicles and pedestrians safely.
Lane reductions, limited access, and temporary loss of on-street parking may occur.
Trenches are backfilled and repaved, typically restoring only the narrow strip of pavement above the excavation.
Only sections of the street directly affected by the work receive new pavement.
Project timelines vary based on weather, site conditions, and unexpected utility conflicts.

Islay Sewer Replacement

The Islay Sewer Replacement Improvements will replace and upgrade aging pipelines that have reached the end of their service life. These improvements will help prevent backups, reduce flooding risks during storms, and improve overall system capacity.

Project Highlights

Replacement of 2,741 linear feet of sewer mains
Upsizing select sewer pipes from 8-inch to 12-inch diameter for added capacity
Replacement of 363 linear feet of storm drain pipes
Upgrading an 8-inch storm drain pipe to 12-inch diameter to handle larger storm flows

More About the Work

The sewer portion of the project includes installing new sewer mains and increasing the diameter of certain segments to reduce the risk of backups and overflows.
The storm drain improvements involve replacing failing pipes and upsizing key sections to improve stormwater flow and reduce the likelihood of capacity-related failures during heavy rain events.

Expected Timeline

Start: Fall 2026
End: Early 2027

California Waterline Replacement

The California Waterline Replacement Improvements aim to replace a key pipeline that carries large volumes of the City's water that has been in service since the 1960s. Upgrading this aging pipeline now will help prevent costly emergency repairs, minimizes service interruptions for customers, and allow maintenance crews to focus more on preventive work that extends the life of the entire water system.

Project Highlights

Replacement of 1,660 linear feet of water transmission main
Upgrading a critical 16-inch cast iron pipeline (installed in the 1960s) to a 16-inch ductile iron pipeline

More About the Work

The existing 16-inch cast iron water transmission main is an important connector in the City’s water distribution network. Because of its age and material, it is more prone to failures, which can result in unexpected outages and costly repairs. Replacing it with a new ductile iron pipeline will strengthen the system, improve reliability, and support more efficient long-term maintenance planning.

Expected Timeline

Start: Fall 2026
End: Early 2027

Browse our FAQs

FAQ Box

How are sewer and waterline projects being funded?

The City's sewer and waterline projects are being funded through the sewer and water funds generated from user fees, which are earmarked specifically for the maintenance, repair, and enhancement of the sewer and water infrastructure.
How are sewer and waterline projects done safely?

All City projects follow strict safety guidelines for both workers and the community. Appropriate traffic control measures, construction barriers, and warning signs will be in place to ensure everyone’s safety.
How do sewer and waterline projects ensure environmental compliance?

The City is committed to following all environmental regulations to minimize impacts on local ecosystems. We always take steps to prevent soil erosion, ensure stormwater protections are secured throughout project sites, and properly dispose of waste materials.
How long does it take to replace a sewer line?

Sewer replacements of aging vitrified clay sewer pipes are larger projects and are expected to take a few months. For each sewer replacement project, we will provide an estimated timeline with key milestones upon project initiation.
What should I do if I experience a problem with my water or sewer service during projects?

If you encounter any issues, please contact the Utilities Department at (805) 781-7215 for assistance. If the issue is an emergency condition, please call 911 immediately.
Why are sewer and waterline replacement projects necessary?

As sewer and water lines age, repairing them is no longer the best solution nor is it cost-effective. Replacing them will help improve the overall infrastructure, prevent frequent failures, and ensure a more reliable system for residents.
Will driveways or streets be blocked during sewer or waterline projects?

Temporary street closures or detours may be necessary. The City and contractors will notify residents of any street closures or changes to access in advance. Driveway access may also be limited during certain phases, but we will make every effort to minimize inconvenience.
Will sewer and waterline projects result in costs to residents?

In most cases, the cost of sewer and water line replacement is covered by the project. However, if the replacement requires work on your private property, there may be additional charges, and you will be notified in advance.
Will water or sewer service be interrupted during sewer or waterline projects?

Yes, there will be temporary interruptions during specific phases of each project. Residents will be notified in advance of any planned outages, and the City will work to minimize the duration of any disruptions.

More FAQs

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