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Development Regulations within Flood Hazard Areas

Within unincorporated Kittitas County, Kittitas County Code Title 14.08 regulates the use and development of property within flood hazard areas. These regulations are a result of the County’s participation in the National Flood Insurance Program (NFIP). With the County’s participation, residents are able to purchase flood insurance which is a requirement of virtually every mortgage or home equity loan for property located within the floodplain. In exchange for offering insurance, the NFIP requires participating jurisdictions to regulate development within FEMA’s regulatory floodplains. All jurisdictions within Kittitas County participate in the NFIP, and each jurisdiction has its own development regulations.

The basic NFIP regulations can be found in 44 CFR: Emergency management and Assistance, Sections 59 and 60.

Washington State’s floodplain regulations can be found in RCW 86.16 Floodplain Management.

Kittitas County’s Flood Damage Prevention ordinance can be found in KCC 14.08.

Development defined

Development is defined as: Any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials located within the areas of special flood hazard (KCC 14.08.020).

Flood development permit

Prior to beginning any development, landowners must apply for a flood development permit from Kittitas County Public Works or their local jurisdiction.

Structures in the floodplain

Structures are allowed within the floodplain as long as they are constructed to meet the requirements of the NFIP. Within unincorporated Kittitas County, residential structures within the floodplain must be elevated 1-foot above the base flood elevation (BFE). The BFE is identified on the FIRM and is the level of the water during a 100-year flood. For example, if the elevation of your land is 1500 feet, and the BFE is 1502 feet, there will be two feet of water on the ground during the 100-year flood. Because structures must be constructed 1-foot above BFE, your structure’s lowest floor will need to be constructed 3-feet above the ground.

Non-residential structures within the floodplain must be either elevated 1-foot above the BFE or flood proofed to 1-foot above the BFE.

Basements are not allowed within the floodplain and crawl space depth is limited. Because solid walls can collapse from the pressure of rising flood waters, openings that allow the flood waters to flow through are required if the crawl space is enclosed. Utilities, such as HVAC systems, electric systems and hot water heaters must be installed above the BFE regardless of whether they are inside or outside of your home. Propane and other fuel tanks must be elevated above the BFE and/or anchored to prevent them from floating away. Structures must be properly anchored to their foundation to prevent shifting during a flood.

Below Grade Crawlspace Construction Requirements

Substantial improvement / substantial damage

Many structures within the floodplain were constructed prior to these regulations and are not constructed or elevated to today's standards. These structures are known as pre-FIRM. To prevent these structures from continued damage the NFIP has a substantial improvement rule. Substantial improvement is any reconstruction, rehabilitation, addition, remodel or other improvement to a structure that has a total cost which equals or exceeds 50% of the market value of the structure before the start of construction. For example, if you own a pre-FIRM home with a market value of $100,000 and you plan a remodel with a total cost of $75,000, your remodel qualifies as a substantial improvement. You will be required to bring your home up to current NFIP standards, which may include elevating your home above the BFE.

Substantial damage is any repair to a home that has a total cost which equals or exceeds 50% of the market value of the structure before it was damaged. Damage can be from any reason, including floods, fire, earthquakes or any other disaster. Homes that are substantially damaged are required to be brought up to current standards.


The floodway is the channel of a river and the adjacent land areas that must be reserved in order to discharge the base flood without increasing the water surface elevation. The floodway can be a dangerous place during a flood, due to the potential for high velocity debris filled water. For these reason, floodways within unincorporated Kittitas County receive special attention and have the following requirements:

  • KCC 14.08.300(2): Construction or reconstruction of residential structures is prohibited within designated floodways, except for:
    1.  Repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and
    2. Repairs, reconstruction or improvements to a structure, the cost of which does not exceed 50 percent of the market value of the structure either: (i) before the repair or reconstruction is started, or (ii) if the structure has been damaged, and is being restored, before the damage occurred. Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety codes which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions or to structures identified as historic places shall not be included in the 50 percent.
  • KCC 14.08.300(4): Filling in the floodway is prohibited except for residential maintenance. Residential maintenance is considered the importing of bark or top soil for flower beds and gardens. The quantity of material must be able to be hauled in a pick up truck and not require the use of a commercial dump truck. The total amount of material shall not exceed one load per calendar year.
  • All other development is prohibited within the floodway unless a certification by a licensed engineer is provided that demonstrates the proposed development will not cause any increase to the water level during the 100-year flood.

RVs in the Floodplain

The placement of RVs in the floodplain of unincorporated Kittitas County is regulated by KCC 14.08.295. Additional RV regulations are found in KCC 14.04.045.

RVs can become floating hazards during a flood. For this reason, during flood season (November 15th to Memorial Day), unattended RVs are not allowed within the floodplain. A RV is considered to be unattended when a notice is placed on the RV and observed there 72 hours later.

Throughout the year, RVs within the floodplain must be road ready at all times. The RV must be licensed, on its wheel or jacking system, have no permanent attachments or obstructions, and be connected using quick disconnect utilities.

Recreational Vehicles in the Floodplain