Stormwater Requirements for New Construction

Stormwater Requirements for New Construction Resources
Stormwater Presentation (November 8, 2018)»

What is the process?

Determine Applicable Stormwater Management Requirements

There are two Post-Construction Stormwater standards currently in effect in San Luis Obispo County. The post-construction stormwater requirements summary chart summarizes the requirements and their applicability.  Staff can help determine which requirements apply to the project.

Within the Phase II Municipal Permit Area (the County’s Stormwater Management Area) the County applies the Central Coast Post-Construction Requirements. Projects located outside the Stormwater Management Area (in unincorporated areas of the county) that disturb more than 1.0 acre must meet the Post-Construction Standards in the California Construction General Permit.

The County’s Land Use View mapping application can help you determine whether your project is located within the stormwater management area. 

Incorporate Stormwater Management into Plans/Design

Permit applicants must submit either: 

Projects within the County’s Municipal Stormwater Management Area (MS4 Coverage Area) must adhere to the Central Coast Post Construction Requirements.

Projects that do not receive a waiver must incorporate site design and runoff reduction measures during the projects planning stage.  Projects subject to Performance Requirement 2 or above are required to submit a Stormwater Control Plan. Please use the Stormwater Control Plan template provided to facilitate timely review. Public Works staff will review the stormwater control plan during the plan check process utilizing the Post Construction Stormwater Requirements Checklist.

The San Luis Obispo County Low Impact Development Handbook provides guidance on designing stormwater management controls. Refer to the below FAQ for additional resources. The LID Plant Guidance for Bioretention provides guidance for appropriate plants and methods in LID areas.

Create a Post-Construction Plan

The Construction General Permit and the Central Coast Post-Construction Requirements mandate that applicants create an Operations and Maintenance Plan for any structural control measures that are installed to mitigate post-construction stormwater runoff.  

Projects outside the Stormwater Management Area that enroll in the Construction General Permit must also submit an Operations and Maintenance Plan as a component of the site’s Stormwater Pollution Prevention Plan. 
Projects within the County’s Stormwater Management Area must record an Operations and Maintenance Plan with the Department of Planning and Building. Please refer to 
post-construction stormwater management for additional information.

Stormwater Management During Construction

The Department of Planning & Building administers state and federal pollution prevention policies for stormwater runoff for all building permits, verifying that appropriate stormwater permits and plans are in place prior to the commencement of construction.  Please refer to Stormwater Management During Construction for additional information.

Stormwater Management Inspections and Certification

The system design engineer must inspect the stormwater system utilizing the County's SWCP Construction Inspection Checklist or equivalent to ensure the system is in substantial conformance with the approved plans.  In addition, the system design engineer must submit a certification prior to final of construction permits.

Who can use this service?

Anyone applying for a construction permit through the Planning and Building Department or an Encroachment Permit from Development Services.

Is there a charge for this service?

The cost for this service is factored into applicable construction permit fees and in some cases the actual cost via a checking and inspection agreement.

When and where is this service offered?

This service is available throughout the year during regular business hours except during scheduled holidays.

Frequently Asked Questions

Contact Public Works via web form, email, or call us at (805) 781-5252.