Frequently Asked Questions
Below you will find information that might help you understand how to find things or learn about information you might need to know about your city or town.
Grading & Retaining Walls
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Grading & Retaining Walls
Typically, yes, however, the grading design must first be reviewed by the Town. The level of design review generally depends upon the amount of grading proposed and the slope of the property. Based on these factors, the grading design may require approval of the Zoning Administrator, Design Review Board, or Planning Commission with a recommendation to the Town Council and the Town Engineer or their designee. Once the grading design has been approved, the grading plan can be stamped by the Planning Department, and the applicant will then submit the grading plans to the Contra Costa County Conservation and Development Department to apply for the construction grading permit and technical review of the plans, once their review is completed, they will then issue the permits and conduct inspections. Please note that in some cases, at the discretion of the Town Engineer, the Town may conduct the separate technical review of the grading plans and issue permits and conduct inspections. In all cases, the Town Engineering Department will review the plans and/or conduct inspections for C3/NPDES requirements, at additional fee costs for compliance with Federal, State and Local regulations.
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Grading & Retaining Walls
A grading permit is required for any earth movement of more than 50 cubic yards, a cut or fill greater than 3-feet deep and for other conditions as specified in Moraga Municipal Code (MMC Section 14.04.031). MMC Section 14.04.032 lists exemptions to grading permits.
There are three procedures for grading permit approval depending on the slope and quantity of soil displacement. Grading permits may be approved administratively by the Design Review Administrator for slopes less than 20% and for grading of less than 200 cubic yards.
Design Review Board approval is required for grading permits for slopes of 20% or more and where the average predevelopment slope in the area of disturbance is less than 25% and for grading of more than 200 cubic yards.
All grading operations, including landslide repair or slope stabilization, on predevelopment average slopes greater than or equal to 25% require review by the Planning Commission with a recommendation to the Town Council.
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Grading & Retaining Walls
Grading plans need to show the existing topography with a 2-foot contour interval and the proposed alteration in the contours. The total amount of cut or excavated earth and fill soil shall be tallied on the plan. By connecting all the points where the proposed contours diverge from the existing contours, the "area of disturbance" can be shown. The average slope of the area of disturbance needs to be calculated on the plan.
If the project involves grading on any slope steeper than 20%, then a Hillside Development Permit is required and the applicant must submit a report from a qualified geotechnical engineer. The cost of peer review by an independent geotechnical consultant under contract with the Town of Moraga shall be paid for any projects where building is planned in the area of grading or the grading is in close proximity to buildings.
If any grading is occurring during the winter, then a storm water pollution prevention plan (SWPPP) and erosion control plan shall be reviewed by the Town Engineer for consistency with the regulations in MMC Section 14.48.
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Grading & Retaining Walls
The slope density ordinance for the Town of Moraga states that no person may grade, clear, construct upon or alter hillside land without a hillside development permit (MMC Section 8.136.040). Hillside land is defined as any slope of 20% or greater. A 20% slope is equivalent to a 1:5 vertical to horizontal ratio or 11.3 degree angle.
Various factors listed in MMC Section 8.136.050 are considered in reviewing a Hillside Development Permit (HDP), including slope stability analysis, soil characteristics and drainage, among others. Geotechnical reports are usually required from applicants and are subject to peer review by the Town’s Geotechnical consultant. The cost of the peer review is paid by the applicant.
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Grading & Retaining Walls
Exterior retaining walls shall be limited to five feet in height, unless it is visible from off site, in which it shall be no higher than 3 feet. (Design Guidelines ID11.2) The horizontal depth of the terraces between stacked retaining walls should be a minimum of twice the height of the larger adjacent wall (Design Guidelines ID11.4). Retaining walls should be built a minimum of three feet from a property line (Design Guidelines ID11.5). An application to the Design Review Board is required if any exceptions to the above guidelines are requested.
For more information, please refer to the Town of Moraga Design Guidelines document.
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Grading & Retaining Walls
A Hauling Permit is required if more than 500 cubic yards of material will be transported to or from a site (MMC Section 14.04.040-C). The hauling permit is reviewed and approved by the Town Council. Grading projects should try to balance the cut and fill on the property and minimize off-hauling of soil. For more information, please refer to the Public Works Department.
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Grading & Retaining Walls
If the vegetative cover has been removed from a property for construction or grading, then erosion control measures must be installed by October 1st prior to the winter storm season. The storm water pollution prevention plan (SWPPP) shall be submitted for review and approval by the Town Engineer. Builders and grading contractors are responsible to insure that all sediments remain on the project site.
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Grading & Retaining Walls
Generally, the Town prefers natural appearing slopes. When grading is done to create padded lots, the Town’s Design Guidelines require a minimum 10-foot near level clearance along one side of a home for access to the rear yard and a minimum of 6 feet near level clearance on any 3 sides of a building or structure. (Design Guidelines SFR1.10) A 25-foot by 40-foot level yard area is also required on padded lots and this area cannot be within the required front yard.
For more information, please refer to the Town of Moraga Design Guidelines document.
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Grading & Retaining Walls
Anyone making an excavation within the public right-of-way, which generally includes 7 to 12 feet of property between your front property line and the curb or edge of pavement, should contact Underground Service Alert (USA) at 800-642-2444 at least two days before you dig to identify the location of existing underground utility lines, such as gas lines, cable TV and fiber optic telecommunications lines.