Local Transmission Main Mateo Flow Control Vault Improvements Project
Summary
SCH Number
2026040497
Public Agency
South Coast Water District
Document Title
Local Transmission Main Mateo Flow Control Vault Improvements Project
Document Type
NOE - Notice of Exemption
Received
Posted
4/10/2026
Document Description
The South Coast Water District proposes to relocate existing Joint Regional Water Supply System (JRWSS) air/vacuum relief (air/vac) valves that are currently located within an underground concrete vault at the Mateo Flow Control Vault, located within the public right-of-way at the intersection of Avenida Mateo and South El Camino Real in the City of San Clemente (Figure 1, Civil Site Plan). The proposed project would relocate the air/vac valves to above-ground locations adjacent to the existing vault, consistent with current JRWSS standards. Relocating the valves above ground would allow operations staff to access the facilities for inspection, maintenance, and replacement without entering the underground vault.
The existing underground vault and air/vac piping connections to the water transmission main would remain in place. The project would extend the existing air/vac piping from the transmission main through the vault wall and connect the piping to the new above-ground air/vac valves. In addition, the project includes rehabilitation and recoating of existing piping, valves, and fittings within the vault.
Construction activities would be temporary and would involve localized excavation and surface disturbance within previously disturbed roadway and utility areas associated with the existing transmission main, vault, and street improvements, and would not require removal or disturbance of trees or vegetation. Pavement and surface restoration would be completed in accordance with City of San Clemente standards. Any necessary traffic control measures would be implemented in coordination with the City of San Clemente in accordance with applicable standards.
Contact Information
Name
Dylan LaFrance, PE, JD
Agency Name
South Coast Water District
Job Title
Senior Engineer
Contact Types
Lead/Public Agency / Project Applicant
Phone
Email
Location
Cities
San Clemente
Counties
Orange
Regions
Citywide
Cross Streets
Avenida Mateo and South El Camino Real
State Highways
Interstate 5
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
CEQA Guidelines Section 15301(b) - Existing Facilities (Class 1)
Reasons for Exemption
The proposed project is categorically exempt under the “Class 1” categorical exemption (CE), Existing Facilities, as outlined in Section 15301 of the California Environmental Quality Act (CEQA) Guidelines. “Class 1” exemptions consist of operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing public or private structures, facilities, mechanical equipment, or topographical features, involving negligible or no expansion of existing or former use. The key consideration is whether the project involves an expansion of use. One of the examples included under Section 15301 of the CEQA Guidelines is as follows: “Existing facilities of both investor and publicly owned utilities used to provide electric power, natural gas, sewerage, or other public utility services.” The proposed project involves minor alterations to an existing public water utility facilities with no expansion of use.
County Clerk
Orange
Attachments
Notice of Exemption
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