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San Luis Obispo County, California

 > County of San Luis Obispo > Planning and Building > Grading and Drainage

Grading and Drainage


Read our Guide to Residential Grading  to learn about grading and why it can be a concern.  

When a proposed project requiring land use or building permit approval involves 50 or more cubic yards of earth moving, the permit application must include a Grading Plan. 

" As-Built Grading " means grading performed in the field without first obtaining the necessary construction permits allowing the intended grading work.

If the amount of site work qualifies as “grading” under the Grading Ordinance and involves site work on slopes that are 10 percent or steeper, or if any site work is proposed in a watercourse, then the grading is considered “major.”  Go to our Major Grading page.

Grading and Stormwater Management Revisions

San Luis Obispo is presently revising parts of the Land Use Ordinance, Coastal Zone Land Use Ordinance, Coastal Plan Policies, and North Coast Area Plan in order to comply with the National Pollutant Discharge Elimination System (NPDES) Phase Two Requirements.  Learn about the revisions and comment here.


Learn about Drainage Regulations  from the county's Land Use Ordinance, Title 22 of the County Code, and the Coastal Zone Land Use Ordinance, Title 23 of the County Code. Drainage Regulations  apply to land both within and outside of the Coastal Zone .

The Watershed Action Plan is the State Water Board's excepted Watershed Management Plan for 2,000 sq. miles of the Upper Salinas Watershed. The plan contains water management strategies and implements measures to improve water quality, erosion-sedimentation and habitat. To read more about this, visit the Upper Salinas-Las Tablas Resource Conservation District website. The links include related maps and a large document titled "Watershed Action Plan for the Upper Salinas-Las Tablas Area." The document and maps are intended for the general public who are interested in economic and land use issues within the watershed.

Stormwater Information

Learn about new stormwater requirements in effect March 6, 2014.

Help Prevent Stormwater Pollution   Adobe Acrobat icon  [161 KB] - This document provides 10 "easy to do" activities around the house to reduce stormwater pollution in our local creeks and water bodies.

After the Storm   Adobe Acrobat icon [511 KB] - This document provides information on the effects and problems associated with stormwater run-off and information on how to reduce these effects.

Low Impact Development    Adobe Acrobat icon [471 KB] - (A Sensible Approach to Land Development and Stormwater Management) - This document provides information on alternative (non conventional) site design techniques that can be used in development projects.

How Urbanization Effects the Watercycle    Adobe Acrobat icon [1692 KB] - This document provided information on how impervious surfaces associated with urban development can impact the water cycle.

This document answers the question "Does my project require a National Pollutant Discharge Elimination System (NPDES) permit including a Storm Water Pollution Prevention Program (SWPPP)?"  Storm Water Requirements for Grading Permits 

Post Construction:  Stormwater Management for Development and Redevelopment

The Adobe Acrobat icon   Erosion Control Handbook  [12512KB] provides guidelines for erosion reduction methods and measures. The Handbook also provides information on short and long term measures for sedimentation and erosion, guidelines for road construction and maintenance, and soil conservation measures. The handbook is intended for those who are not familiar with soil conservation and describes how what we do to the soil with agriculture and construction directly impacts our waterways.

Environmental Review

Most major grading permits are subject to the California Environmental Quality Act, often referred to as CEQA.  Additional submittals such as (but not limited to) archaeological reports, botanical reports, and geological studies may be necessary.  The required reports may be discussed during a pre-application meeting or in a letter requesting additional information after application.  Please Note:   A filing fee is charged by the County Clerk on behalf of the Department of Fish and Game for most projects that are not exempt from CEQA.