Stormwater Deviation Permit

Bio Retention Area with grass and plants

In some parts of Wake County, homeowners can install a stormwater device to go over the normal impervious surface limit on their lot, up to an impervious area maximum of 30% of the lot.

This applies to:

The rural, non-critical zoning area of the Swift Creek Land Management Plan, which has a normal impervious limit of 12% without onsite stormwater;
Older subdivisions (built before 2006) that don't have a subdivision-wide stormwater plan and don't have a recorded "perpetuity statement," a rule stating impervious limits on each lot will be strictly enforced forever, or
Properties that want to replace traditional pavement areas with permeable pavement.

How do I begin the permitting process?

The stormwater deviation permitting process begins with the building permit. Make sure that your building permit application has a site plan and a table that lists all existing and proposed impervious features. Site plan requirements can be found here (Spanish version).

If your property is eligible for a stormwater deviation permit, Watershed Management staff will request a Stormwater Certification review, as a step in the building permit review. The Stormwater Certification review costs $50. After payment, staff will calculate the size of stormwater device needed to offset the proposed improvements which go over the normal impervious surface limit. Staff will discuss options for revising your building plan or pursuing a stormwater deviation.

What items do I need for submittal?

Required Document	Description
Single Family Residential Stormwater Deviation Submittal Checklist	Checklist with permitting instructions and certification
Stormwater Deviation Application	Application Form
Stormwater Management Plan – Stormwater Device Plan	Brief description of the scope of work Stormwater device plan and profile views detailing proposed elevations, slopes, vegetation, orifice sizing, weirs and other elements that meet minimum device standards Volume calculations of stormwater to be managed
Stormwater Management Plan – Site Plan	Amended site plan submitted to the building department with the following additional information Location, type and relevant dimensions and capacities of stormwater management structures and other devices Delineate area of impervious surface to be directed to the stormwater device. Show how the stormwater will reach device, pipe network or swale. Show discharge point from device to swale, rear of property, etc. Existing or proposed well, septic tank and drain field location(s) or sewer and water easements and proposed connection location(s).

Please submit these documents for a Stormwater Deviation permit through the Wake County permit portal. Instructions for setting up a permit portal account are available here.

Note:

A $400 review fee must be paid to initiate processing. This review fee also covers the permit issuance fee.
The stormwater planning process can occur in parallel with the on-site wastewater design; however, the stormwater devices may not be placed in well, septic or repair areas. The on-site approval shall preclude the stormwater plan approval.

Stormwater control measure options for residential lots

Small deviations can often be handled by the applicant or homeowner. Larger stormwater management devices should be designed by a qualified professional. Options include:

Rain Gardens
Cisterns (above-ground or underground tanks)
Rain barrels
Infiltration devices
Dry detention basins
Permeable pavement – requires an engineered design

Engineering design isn't required for most systems. Permeable pavement is the exception; it must comply with the state manual. For technical details, see section 4.3.2 of the Wake County Stormwater Design Manual.

How do I complete my permit after I have built the stormwater device?

After the building and stormwater improvements are constructed in accordance with the approved plan, the homeowner must obtain an as-built survey from a licensed land surveyor and submit two agreements related to the stormwater device.

Requirement	Description
Submit the final as-built survey to the stormwater deviation permit	Must include: If parcel is less than 5 acres, scales of 1" = 30', 40', 50', 60' or 100' are acceptable. A detailed impervious summary for the lot Location of impervious surfaces Location of stormwater devices Plan and profile views of the stormwater device(s) (an addendum documented by the designer may also be provided) Indicate impervious areas from which stormwater is collected (an addendum documented by the designer may also be provided) Conveyance system for routing stormwater from impervious area to device (an addendum documented by the designer may also be provided) Property setbacks, buffers, flood zones or any existing easements Location of wells, septic and repair areas
Approval of the as-built survey from Watershed Management	Approval by the plan reviewer to determine whether the survey follows the approved Stormwater Management Plan Approval by the stormwater inspector to determine whether the survey accurately depicts field conditions
Stormwater Agreement	Agreement that homeowner is aware that a stormwater device is on the property and needs to be maintained Must be notarized Must be recorded at the Wake County Register of Deeds
Operation and Maintenance Agreement	Agreement about how to maintain the stormwater device Must be appropriate for the installed stormwater device (prepared examples are available here) Must be notarized Must be recorded at the Wake County Register of Deeds

How do I submit the Annual Owner Stormwater Inspection report?

If your property has a stormwater feature, you must complete and submit the Homeowners Annual Inspection Checklist each year after construction is complete, for as long as the stormwater feature remains in place. Learn more about the inspection requirements.

Complete the checklist

Questions?

Please contact Watershed Management at 919-856-7436.

For additional guidance please review section 4.3.2 of the Stormwater Design Manual or set up a presubmittal consultation meeting at wake.gov/WMhelp

Apply for a permit!