Development, Permits & Elevation Certificates
Development, Permits and the Elevation Certificate
A floodplain development permit is required for ALL development within the floodplain. For projects that otherwise require a permit such as a new home or adding a substantial amount of fill to a site, this is a part of the permit review. Activities in the SFHA (Special Flood Hazard Area) that may not otherwise require a permit, such as limited grading, fill or the construction of a small detached shed, do require a floodplain development permit. Floodplain development permits, like most other City permits, are issued at the Permit & Information Center, which is located at 99 West 10th Avenue.
Note: Any development to a wetland, even outside of the SFHA, may require state and federal approval.
Land Use Code
Development under our Land Use Code for floodplain purposes is defined as any man-made change to improved real estate, including but not limited to:
Elevation CertificatesElevation Certificates are required for all new construction and substantial improvements. Substantial improvements are defined as any reconstruction, rehabilitation, addition or other improvement to a structure, the total cost of which equals or exceeds fifty percent of the market value of the structure before the start of construction of the improvement.
Commercial structures which are not used as dwellings or for overnight stays, such as hospitals, can be flood-proofed instead of elevated. Flood-proofed structures are designed to be substantially impermeable to the passage of floodwaters and to withstand the forces floodwaters can exert onto the structure.
Flood-proofed structures are certified using a Floodproofing Certificate instead of an Elevation Certificate. Please note that for insurance purposes flood-proofed structures are rated as if they are protected to a height one foot lower than they are actually protected.
To minimize potential damage caused by flooding, construction within the floodplain, aka the Special Flood Hazard Area (SFHA), is regulated by local, state and federal regulations. Elevation of structures is a key component of these requirements. Required elevations are identified during the permit review process, and are noted on the approved set of plans. Two Elevation Certificate forms will be attached to the plans during plan review and must be completed by a licensed land surveyor, engineer or architect who is authorized by law to certify elevation information.
Elevation Certificate forms can be obtained here.
BuildingBuilders should work closely with their surveyor to identify and mark on-site the minimum required elevations of the building floor, ducting, heat pumps, electrical and other building equipment. This should be done prior to foundation work. The surveyor should return during early construction to verify the height of the crawlspace, vents, duct work and the finished floor.
When the structure is completed, the surveyor must confirm the height of mechanical equipment (like heat pumps) and the height of the adjacent grade. Inspectors will ask for a preliminary Elevation Certificate when the lowest floor is in place.
For typical construction, the verification will occur at the Underfloor Framing inspection when the height of the floor can be identified. Of course, that is too late if you find the foundation was constructed too low. Check early and request that your surveyor provide an elevation reference point before forms are set.
At the completion of a project, the inspector will pick up the completed Elevation Certificate and verify some of the basic information such as the diagram used, and the number, size and type of flood vents. If the paperwork is not in order, the building will not receive final inspection approval.
Some easily missed items are:
- All mechanical equipment (this includes ducting) must be elevated to one foot above the base flood elevation even if it is in an attached garage or outside the structure.
- The bottom of required vents cannot be more than one foot above adjacent grade.
- Crawlspaces below grade on all sides are prohibited (fill can be added to raise the crawlspace height to comply but must meet other required clearances).