About Flood Control

What does the District do?

The Purpose and Goals of the District

  • Regulation of floodplains and watershed development
  • Regulation of development in and along watercourses with drainage areas greater than 80 acres
  • Identification of flood hazards and associated problems
  • Construction of flood control structures and drainage related facilities
  • Maintenance and operation of completed structures and facilities
  • Operates a network of Stream and Rainfall Gauges (Rainfall Information)
  • County watercourse and drainage master planning
  • Education for Flood Prevention & Safety
  • Stormwater Management Program for pollutant discharge elimination

 

How is the District funded?

Under State of Arizona enabling legislation, flood control districts are political subdivisions, designated as special taxing districts, and are given the authority to levy a secondary property tax on parcels within the County. The tax rates are set by the Yavapai County Flood Control Board of Directors. Flood Control District projects are funded by a variety of Federal, State, District, County and City cost sharing partnerships.

Federal Regulatory Activities

The Flood Control District also implements the following Federal Emergency Management Agency Programs:

Frequently Asked Questions

What area does the Flood Control District regulate?

The Flood Control District is responsible for floodplain management in all unincorporated areas of Yavapai County as well as regulates FEMA floodplains in incorporated communities of Camp Verde, Clarkdale, Dewey-Humboldt, Jerome, and Wickenburg.

We do not regulate within the city boundaries of Prescott, Prescott Valley, Sedona, Chino Valley, and Cottonwood. 

 

What is the difference between Floodway and Flood Fringe?

There are two delineations within the boundary of the 100 year floodplain/Base Flood known as Floodway and Flood Fringe.

Floodways are designated and mapped through detailed engineering studies. Mapped Floodways includes the channel of a river/watercourse and adjacent land areas which in an unobstructed condition can discharge a 100-year flood/Base Flood without any increase in water surface elevations.

The area between the floodway boundary and limit of the 100 year floodplain is termed Flood Fringe. The Flood Fringe encompasses the portion of this floodplain that could be completely obstructed without increasing the water surface elevation of a 100 year flood event more than 1 foot at any point.

 

What can I do if I am experiencing flooding/drainage on my property?

Please refer to the Guide to Drainage Around the Home material to learn how to handle flooding and drainage on your property. To view click here

 

Why is my road flooding?

Where it rains, it can flood.

There are typically 3 types of roads used nearby water, low-water crossings, bridges, and roads with culverts.

Low water crossings are often used in arid topography where there are shallow channels and infrequent rain events. Low-water crossings are purposefully used in areas of minor or moderate flooding. Low-water crossing roads are often used because they are inexpensive as opposed to bridges. They require little maintenance.  They are structurally strong. They are a good alternative to culverts where there is a lot of woody shrubs or trees or unstable rocks; these can catch debris cause plugging during flooding and become ineffective.

The disadvantages of low water crossing are periodic traffic delays during heavy rain events or the need to reroute. If you live near a road that periodically floods during a rain event and do not have an alternative route to get home we advise developing a safety plan. Please visit the Yavapai County Office of Emergency Management website for alerts, preparedness, mitigation, and tips.  

Do not try to drive or walk through fast-moving water or flooded roads. Even 6” can move a vehicle. Do not drive around road barricades or other closures. “Turn Around Don’t Drown”. Please keep yourself safe from flood hazards. 

Some subdivisions are private roads and are commonly owned by all the separate lot owners who use them. Maintenance of these roads relies on the residents.  If you are not sure if a road is public or private, please contact the Yavapai County Public Works Department or contact your title company. It is also available on the Yavapai County interactive map just turn on the transportation layer and choose county-maintained roads.

To learn how to help minimize drainage or flooding on your property please read our Guide to Drainage Around the Home material.

 

 

Who is responsible for cleaning culverts?

Public Works Department maintains roadway culverts for county-maintained roads. Driveway culverts are the sole responsibility of the property owner.  Culverts within a subdivision could be privately owned or managed by Public Works. If you have questions about the culverts' ownership please contact the Public Works Department.  

 

Who is responsible for cleaning out drainage easements and ditches?

The responsibility of cleaning out drainages from debris, trash, or weeds depends on who owns that drainage. Often this information can be found on a subdivision plat. It may be managed by Flood Control in which case Public Works services those ditches on behalf of Flood Control. If there is no designated owner and it lies on your property then you are responsible for the maintenance of the ditch. 

 

Am I in a flood zone?

To learn if a property is in a flood zone or affected by watercourses please visit and fill out the Flood Hazard Status Report Request. You can also email Flood.Status@yavapaiaz.gov or call us at (928)771-3197 and a flood hazard status report can be emailed to you.

 

What do the Flood Zones mean?

Moderate to Low-Risk Areas

Flood Insurance is not mandatory but recommended. In these areas, the risk of being flooded is reduced, but not completely removed. One in three insurance claims come from moderate- to low-risk flood areas.

Shaded Zone X- Area of moderate flood hazard, usually the area between the limits of the 100‐year and 500‐year floods.

Zone X (Unshaded)-Area of minimal flood hazard Zone X is the area determined to be outside the 500‐year flood.

 

High-Risk Areas

High-risk flood areas begin with the letters A or V on FEMA flood maps. These areas face the highest risk of flooding. If you own a property in a high-risk zone and have a federally-backed mortgage, you are required to purchase flood insurance as a condition of that loan.

Zone A- Areas with a 1% annual chance of flooding and a 26% chance of flooding over the life of a 30‐year mortgage. Because detailed analyses are not performed for such areas; no depths or base flood elevations are shown within these zones.

Zone AE- The base floodplain where base flood elevations are provided. AE Zones are now used on new format FIRMs instead of A1‐A30 Zones.

Zone AH-Areas with a 1% annual chance of shallow flooding, usually in the form of a pond, with an average depth ranging from 1 to 3 feet. These areas have a 26% chance of flooding over the life of a 30‐year mortgage. Base flood elevations derived from detailed analyses are shown at selected intervals within these zones.

Zone AO- River or stream flood hazard areas, and areas with a 1% or greater chance of shallow flooding each year, usually in the form of sheet flow, with an average depth ranging from 1 to 3 feet. These areas have a 26% chance of flooding over the life of a 30‐year mortgage. Average flood depths derived from detailed analyses are shown within these zones.

Zone AR- Areas with a temporarily increased flood risk due to the building or restoration of a flood control system (such as a levee or a dam). Mandatory flood insurance purchase requirements will apply, but rates will not exceed the rates for unnumbered A zones if the structure is built or restored in compliance with Zone AR floodplain management regulations.

Zone A99- Areas with a 1% annual chance of flooding will be protected by a Federal flood control system where construction has reached specified legal requirements. No depths or base flood elevations are shown within these zones.

Undetermined Risk Areas

Flood Insurance is not mandatory but recommended.

Zone D- Areas with possible but undetermined flood hazards. No flood hazard analysis has been conducted. Flood insurance rates are commensurate with the uncertainty of the flood risk.

Important *Despite the flood zones, flood insurance is regulated via federally backed loans. A lender can require flood insurance even if you are not in a floodplain (ie: close to one or even part of the property is in one but not the home), that is at the lender's discretion The purchaser has the option to shop for loans. 

 

What is the 100-year flood?

The term 100 year flood is misleading, most think it is a flood event which occurs only once in a 100 year time span. Rather, it is a flood elevation that has a 1% chance of being equaled or exceeded each year. Thus, the 100 year flood could occur more than once in a relatively short period of time

The 100 year flood, which is the standard used by most Federal and State agencies, is used by the National Flood Insurance Program NFIP as the standard for floodplain management and to determine the need for flood insurance.

A structure located in a 100 year floodplain has a 26% chance of suffering flood damage during the term of a 30 year mortgage, and a greater chance of being damaged by a flood than by fire.

 

What is the 80-acre Drainage Policy?

On April 9, 1990, the Board of Directors for the Yavapai County Flood Control District adopted the following policy regarding watercourses with a tributary drainage area less than 80 acres:

“Violations or possible violation in a watercourse with a tributary drainage base area of less than 80 acres at the point of the violation or possible violation shall be considered as minor in nature since they do not pose a significant potential for loss of life and property and as such are not subject to enforcement actions by the District. The normal method of determining tributary drainage basins shall be delineation on a USGS 1″ = 2000′ scale topographic map. Not withstanding the above, the District Ordinance shall be strictly enforced within the District delineated areas of special flood hazard and within subdivisions and other developments where areas of special flood hazard were or will be delineated under District requirements as a condition of approval.”

In general terms, the policy means that the District will not require conformance with the District Ordinance when the tributary drainage area at the point of the potential violation is less than 80 acres. This policy does not relieve property owners from potential liability resulting from watercourse alterations. The 80 acre drainage policy does not apply to the review and approval of new subdivisions, use permits, zone changes and related items. For more specific information regarding this policy, contact the District office.

 

What is the Regulatory Elevation?

The Federal Emergency Management Agency requirement for building structures in flood hazard areas is that the floor of the lowest habitable enclosure must be elevated to or above the base flood elevation (BFE). The BFE is based on the floodplain delineation for the 100-year peak runoff event.

In order to minimize potential damage to residential structures in flood hazard areas the State and Flood Control District requires an additional foot of free board of above the BFE, which is referred as the Regulatory Flood Elevation.

To learn more about what to include in your permits for Flood Control visit https://www.yavapaiaz.gov/Resident-Services/Flood-Control/Permitting-Resources

 

Do I need a registered engineer to prepare my building permit plans?

An Arizona registered engineer is needed for residential structures Building Permit Checklist Requiring Civil Engineering(PDF, 423KB)) constructed in floodways, in flood fringe areas with depths of flow typically greater than 2 feet, approximate Zone A study area, areas impacted by watercourse with drainage areas greater than 80 acres, and for most commercial developments (Commercial Building Permit Requirement Checklist(PDF, 100KB)). For structures located in FEMA or Yavapai County flood hazard areas an Elevation of Floodplain Property Form(PDF, 157KB) will need to be completed by an Arizona Registered Land Surveyor. In most cases, the engineering requirements are site specific. Call the Flood Control District with the parcel number and an idea of where the structure will be located on the property for a more detailed answer.

 

What does Flood Control need for my permits?

Please see our Permits Resource page. For all other permitting inquiries please contact Yavapai County Development Services.

 

How far away from the watercourse does my house need to be?

The location of the structure in proximity to a wash is dependent on the size of the wash. A Hydrologist will review an application to determine if a location is acceptable during the building permit review. An Arizona Registered Civil Engineer may need to determine the appropriate setback or design appropriate erosion control measures. Feel free to reach out to us with further questions. 

 

Why do I need openings in my foundation?

An important objective of the National Flood Insurance Program NFIP is to protect buildings constructed in floodplains from damage caused by flood forces. Although the finished floor of a building may be well elevated above flood levels, if constructed on an enclosed extended foundation/stem wall with crawl space, these foundation walls are subject to flood forces which include hydrostatic pressure. If the foundation/stem wall is not specifically designed to withstand hydrostatic pressure, they can cause damage to the structure.

In order to prevent such damages the NFIP has implemented the requirement for openings in foundation/stem and other enclosure (garage, detached non habitat structures) walls. These openings allow automatic entry and exit of floodwaters. During a flood event flood waters will reach equal levels on BOTH sides to the wall, thus reducing the potential; for damage from hydrostatic pressure. Having proper flood openings may also reduce your cost of flood insurance.

Note: Depending on site conditions additional foundation requirements may apply. They are outlined in the following documents:

Quick guide to Flood Vents

•Summary of Requirements for Construction in Flood Hazard Areas Where Base Flood Elevations Have Been Established(PDF, 87KB)

•FEMA Technical Bulletin(PDF, 4MB)