New buildings in the floodplain must be protected from flood damage. Douglas County's building code requires that new structures must be elevated at least one foot above the base flood elevation  (or a minimum of 2’ elevation in the Urban Growth Area of the City of Lawrence). No new construction or filling is allowed in the floodway, unless it can be demonstrated through hydrologic analysis that it will not increase in the base flood elevation.  Development includes any man-made change to the land or buildings, including, but not limited to:

• the construction of structures or additions to structures,
• the placement of mobile homes or accessory structures,
• the renovation, repair or improvement of the interior and/or exterior of existing structures,
• the conversion of garages, carports, storage rooms, porches, patios and similar spaces into living space,
• the addition or replacement of any machinery and equipment (HVAC units, propane tanks, etc.) servicing the building,
• mining, dredging, filling, grading, paving, excavating, drilling,
• the storage of materials or equipment.

Structures are required to be dry floodproofed and have the lowest floor elevated at least 1’ above the Base Flood Elevation (or a minimum of 2’ elevation in the Urban Growth Area of Lawrence). The minimum elevation applies to HVAC, water heaters, heat pumps, and similar machinery and equipment.

Wet floodproofing is permitted for Ag buildings and other non-habitable structures.

Always call the Douglas County Zoning & Codes Department at 785.331.1343 before you build, alter, re-grade or fill on your property.  If you see building or filling without the County's approval, please notify us.  A permit is required to ensure that projects do not cause problems on other properties and meet local, State and Federal requirements.

If new construction or renovations are in the floodplain, a flood development permit  is required prior to the issue of the building permit.

Please see Douglas County Floodplain Management Regulations 12-328 for construction in floodplains.

Additional helpful information:

• FEMA Technical Bulletin 1 - Openings in Foundation Walls and Walls with Enclosures
• FEMA Technical Bulletin 2 - Flood Resistant Materials:  Flood damage resistant materials requirements for buildings located in the special flood hazard district
• FEMA Dry Floodproofing - Dry floodproofing structures
• FEMA Technical Bulletin 7 - Wet Floodproof: Wet floodproofing requirements for structures located in the special flood hazard areas
• FEMA Non-Residential Floodproofing - Requirements and certification for buildings located in special flood hazard areas
• Other FEMA Publications

 

Allowable Rise - The Allowable Rise in a floodplain is simply the amount of rise in floodwater that FEMA or a local municipality will allow as caused by man-made structures, placement of fill material, etc.  The allowable rise is used as the basis for delimiting a floodway.

Base Flood Elevation (BFE) -  Defined by FEMA as the height of the base (100-year) flood in relation to a specified datum, usually the National Geodetic Vertical Datum of 1929 or North American Vertical Datum of 1988. Generally speaking, this is the elevation of the 100-year floodwaters relative to "mean sea level". BFE is not depth of flooding. To determine depth of flooding, you would need to subtract the lowest elevation of a particular property from the BFE. For example, if the property's foundation was at an elevation of 125 feet and the BFE was 131 feet, then one might infer that the 100-year depth of flooding would be approximately 6 feet.

Base Flood Approximation (BFA) - Flood mapping that shows the approximate outline of the base floodplain. An approximate study does not produce a base flood elevation.

Bench Marks - Monuments on the ground that show the elevation of the spot above sea level.

Building (Structure) - A walled and roofed structure that is principally above ground.  The term includes manufactured homes, mobile homes and gas or liquid storage tanks.

Conveyance - Conveyance is a term commonly referring to the amount of area water needs to maintain its flow.  Specific to floodplains, conveyance is the area that flood flows require to pass the peak flood flow rate.  If, say, conveyance is increased by digging a larger channel for flood flows to pass through, it would likely result in lowered flood elevations and/or lowered water velocities.

Conditional Letter of Map Amendment - CLOMA.  A statement from FEMA that if a project is constructed as planned, a letter of map amendment can be issued later.

Conditional Letter of Map Revision - CLOMR.  A statement that if a project is constructed as planned, a letter of map revision can be issued later.

Federal Emergency Management Agency - FEMA.  FEMA manages the National Flood Insurance Program (NFIP). In 2003, FEMA became part of the U.S. Department of Homeland Security. 

Flood Insurance Rate Map- FIRM.  The FIRM is where to look for flood information on a property or region.  The FIRM is a map provided by the National Flood Insurance Program (NFIP) showing floodplain boundaries and sometimes floodway boundaries, depending on the level of study that an area has received.   Some of the older FIRM’s do not have floodway mapping, and separate Floodway maps provided by the NFIP must be obtained.

Floodplain - The floodplain line represents the extents to which flood waters would encroach in a specified flood event.  Most commonly, the 100-year flood event is shown on flood map-ping done by FEMA and local municipalities.  Also, the 500-year flood event is typically shown on flood mapping done in more populated areas.

Floodway - The floodway is a theoretical line which represents the limits to which the flood-plain could be constrained (filled in, blocked, etc.) before a specified allowable rise in flood elevation occurs.  Commonly, the allowable rise ranges from 6- to 12- inches. 

Flood Fringe - The flood fringe is the area between the floodplain line and the floodway line.  As discussed above, the floodway represents the limits to which the floodplain could be filled in.  Accordingly, the flood fringe is the area of the floodplain that can be filled with the assurance that the allowable rise in flood elevation will not be exceeded.

Flood Insurance Rate Map - FIRM.  An official map of a community, on which the Federal Insurance Administration has delineated both the Special Flood Hazard areas and the risk premium zones applicable to the community.

Flood.  A general and temporary condition of partial or complete inundation of normally dry land areas.

Flood Fringe.  The portion of the floodplain lying on either side of the floodway.

Flood Hazard Mitigation.  All actions that can be taken to reduce property damage and the threat to life and public health from flooding.

Flood Mitigation Assistance.  A grant program funded by the National Flood Insurance Program.

Floodplain.  Any land area susceptible to being inundated by flood waters from any source.

Floodproofing. Protective measures added to or incorporated in a building that is not elevated above the base flood elevation to prevent or minimize flood damage.  "Dry floodproofing" measures are designed to keep water from entering a building.  "Wet floodproofing" measures minimizes damage to a structure and its contents from water that is allowed into a building.

Floodway.  The stream channel and that portion of the adjacent floodplain which must remain open to permit passage of the base flood.

Geographic Information System - GIS.  Computer based map system that allow the user to keep a map updated easily and to correlate geographic information with other data, such as tax records on properties.

Letter of Map Amendment - LOMA.  The LOMA process is administered by FEMA and can be utilized to amend/revise a Flood Insurance Rate Map (FIRM).  The LOMA is very similar to a LOMR-F, and is used to show that due to the existence of high ground or fill material, an area or structure should be removed from the floodplain.  The LOMA has certain restrictions applied to the timing of placement of fill.  In short, a LOMA can only be used if fill was placed prior to the date of the first FIRM identifying the floodplain to be amended. 

Letter of Map Revision - LOMR.  The LOMR process is administered by FEMA and can be utilized to revise a Flood Insurance Rate Map (FIRM).  The LOMR is typically used to show more complex changes to the floodplain than simply the placement of fill, as with the LOMR-F.  The LOMR can be used to show corrections to floodplain and floodway mapping, changes in regional hydrology (determination of flood flows), addition of bridges or structures within a waterway, etc.

Letter of Map Revision based on Fill - LOMR-F.  The LOMR-F process is administered by FEMA and can be utilized to revise a Flood Insurance Rate Map (FIRM).  The LOMR-F is used to show that due to the placement of fill, an area or structure has been raised out of the floodplain.

Market Value.  The price a willing buyer and seller agree upon.

National Flood Insurance Program - NFIP.  The NFIP is the federal agency which oversees the nation’s database of Flood Insurance Rate Maps (FIRM), in addition to serving many other flood related functions.

Non-structural Flood Protection Measures.  Administrative tools for controlling flooding and flood damage, including regulations on development, building codes, property acquisition and structure relocation, and modification of existing buildings.

No-Rise Certification.  A certification by an engineer that a project will not cause a set increase in flood heights.

Ponding. Runoff that collects in depressions and cannot drain out, creating a temporary pond.

Post-FIRM Building.  For insurance rating purpose, a post-FIRM building was constructed or substantially improved after December 31, 1974, or after the effective date of the initial Flood Insurance Rate Map of a community, whichever is later. A post-FIRM building is required to meet the National Flood Insurance Program's minimum Regular Program flood protection standards.

Pre-FIRM Building.  For insurance rating purposes, a pre-FIRM building was constructed or substantially improved on or before December 31, 1974, or before the effective date of the initial Flood INsurance Rate Map of the community, whichever is later.  Most pre-FIRM buildings were constructed without taking the flood hazard into account.

Probability.  A statistical term having to do with the size of a flood and the odds of that size of flood occurring in any year.

Regular Program.  Also called the Regular Phase. The phase of community participation in the National Flood Insurance Program that begins on the date of the Flood Insurance Rate Map or when the community adopts an ordinance that meets the minimum requirements of the NFIP and adopts the technical data provided with the FIRM, whichever is later.  Nearly all communities participating in NFIP are in the Regular Program.

Runoff.  Rainfall and snowmelt that reaches a stream.

Special Flood Hazard Area  -SFHA.  Land areas that are at high risk for flooding.

Stormwater Management. Efforts to reduce the impact of increased runoff that results from new development.

Substantial Damage.  Damage of any origin sustained by a structure whereby the cost of the re-storing the structure to its undamaged condition would equal or exceed 50% of the market value of the structure before the damage occurred.

Substantial Improvement.  Any reconstruction, rehabilitation, addition or other improvement to a structure, the total cost of which equals or exceeds 50% of the market value of the structure before the start of construction of the improvement.  The definition of "substantial improvement" includes buildings that have been repaired after suffering substantial damage. [Special exceptions apply minimum code requirements and listed properties on an historic register.]

Watershed. An area that drains into a lake, stream or other body of water.

Wet Floodproofing. Protecting a building from flood damage by using flood-resistant materials below the flood level and elevating things subject to flood damage above the flood level.

Zones.  Special Flood Hazard Areas are designated by zones.

Flood Zones

Zone	Type	Definition
Five types of A	A	SFHA where no base flood elevation is provided. This link, Managing Floodplain Development in Approximate Zone A Areas - A Guide for Obtaining and Developing Base (100 yr) Flood Elevations,  will help engineers, land surveyors and architects determine a base flood elevation when no study was performed for the flood area.
	A#	Numbered A Zones (e.g., A7 or A14), SFHA where the FIRM shows a base flood elevation in relation to NGVD.
	AE	SFHA where base flood elevations are provided. AE Zone delineations are now used on new FIRMs instead of A# Zones.
	AH	Areas of 1 percent annual chance shallow flooding with constant water-surface elevation (usually areas of ponding) where average depths are between 1 and 3 feet.
	AO	SFHA with sheet flow, ponding, or shallow flooding. Base flood depths (feet above grade) are provided.
Zone B		Area of moderate flood hazard, usually depicted on Flood Insurance Rate Maps as between the limits of the base and 500-year floods. B Zones are also used to designate base floodplains of little hazard, such as those with average depths of less than 1 foot.
Zone C		Area of minimal flood hazard, usually depicted on Flood Insurance Rate Maps as above the 500-year flood level. B and C Zones may have flooding that does not meet the criteria to be mapped as a Special Flood Hazard Area, especially ponding and local drainage problems.
Zone D		Area of undetermined but possible flood hazard.
Zone V		The Special Flood Hazard Area subject to coastal high hazard flooding. There are three types of V Zones:  V, V#, and VE, and they correspond to the A Zone designations.
Zone X		Newer Flood Insurance Rate Maps show Zones B and C (see above) as Zone X.

 

 

ADDITIONAL RESOURCES:

• Floodsmart.gov GLOSSARY
• FEMA Definitions/Glossary (pdf)

 

 

 

 

Douglas County has developed an interactive mapping system that allows users to access preliminary floodplain information online and locate their property to see if their is floodplain on the property and if there was a change since it was last delineated.

Converting floodplain maps to a digital format is one more step towards FEMA’s goal to acquire better more accurate mapping. It does not address all the flaws in existing maps. However, it will make the maps easier to change in the future and reduce the costs of printing new maps in the long term. Processing Douglas County's floodplain maps to a digital format for distribution in electronic media and made available on the internet will increase availability to more people than ever before.

To use the GIS map viewer, you will need to access the website, Douglas County's floodplain maps  .  Follow the user's guide and it will instruct you on how to use the GIS mapping system.

Before/During/After Rain Events

Before it rains:

• The Douglas County Public Works Department conducts an annual road and ditch maintenance program, which includes the periodic inspection of major drainage channels, roadside ditches and large culverts to reduce/remove water flow stoppage.
• Always check with the Douglas County Zoning & Codes Department before you build on, fill, alter to regrade your property.  A permit may be needed to ensure  that such projects do not cause problems on other properties.
• Every piece of trash can contribute to flooding.  Grass clippings and branches can accumulate and plug channels.  If your property is next to a ditch, creek, storage basin or other waterway, please be aware and keep the banks clear of brush and debris.
• Do not clump or throw anything into drainage ditches, creeks, basins or other waterways. Such dumping causes pollution and is a violation of Federal, State and Local codes. See Douglas County Zoning Regulations 12-304-6.10.03(b)
• Remove trash, fallen branches, and other debris from ditches and drain inlets to help prevent blockages.
• Additional measures to protect a property from flood damage may include retrofitting structures, grading, and such emergency measures as moving furniture and sandbagging.
• Put together a supply kit including battery operated flashlights and radios, first aid and medications, rain gear and warm clothing, sleeping bags or bedding materials, several days worth of canned and non-perishable food, bottled water and other personal items you must have for health and safety.
• Create a family emergency/evacuation plan.  Make sure everyone knows where to go in the event of flooding.  Make a list of those places you could go--friends or families homes, shelters of other safe public buildings on higher ground. Each family member should have a written list of the locations and phone numbers in preference order.
• Elevate your water heater, furnace and electrical panel to minimize damage if they are in flood-prone areas of your home.
• If necessary, construct barriers to stop floodwater from entering the building and seal walls in basements with waterproofing compound.
• Check with your insurance agent on whether or not flood insurance is available for your home. Consult a professional when making flood insurance decisions.
• Have a full tank of gas in your car.  It will be your quick getaway if the time comes for you to evacuate.
• Another resource for notifications, warnings and preparedness is the Douglas County Emergency Management department.  The Douglas County Emergency Management Plan is written in consideration of the relevant hazards identified in the Douglas County Hazard Analysis and to address the four phases of emergency management. The purpose of the plan is to define, to the extent appropriate, the policies, roles and responsibilities for a local integrated emergency management system within the constraints of existing resources and operational capabilities. The Douglas County Emergency Management Plan contains both a broad conceptual framework (describing the policy and approach to emergency operations for use by local officials) and specific information and direction for managers.
• These direct links can help you keep keep tabs of the river levels near you.

Wakarusa River at Clinton Lake

Kansas River at Lawrence

Wakarusa River Near Lawrence

• Many times flooding along the Kansas & Wakarusa Rivers, or their tributaries, can be predicted days in advance, allowing ample time for warning for preparation or evacuation. However, there is a potential for flash flooding to occur from storms after the ground has become saturated or when there is heavy rainfall within a short duration of time.

 

During a flood watch or warning:

• Listen to the radio or television for information.  If you notice unusual flooding or a rapid rise in water in creeks or streams, notify Douglas County Emergency Management at 785.832.5259. Contact your Township Board or the Douglas County Public Works Department if roads are flooded and barricades need to be placed. Tune your radio to KLZR-FM 105.9-for local and National Weather Service Updates. Local radio and TV stations will also interrupt programs to advise you on weather alert situations.
• Be aware that flash flooding can occur.  If there is any possibility of a flash flood, move immediately to higher ground.  Do not wait for instructions to move.
• Be aware of stream, drainage channels, and other areas known to flood suddenly.  Flash floods can occur in these areas with or without typical warnings such as rain clouds or heavy rain.
• If you must evacuate, secure your home.  If you have time, bring in outdoor furniture. Move essentials items to an upper floor.
• Turn off utilities at the main switch or valves.  Disconnect electrical appliances. Do not touch electrical equipment if you are wet or standing in water.
• If you must leave your home, remember these tips:
  • Do not walk through moving water. Six inches of moving water can make you fall.  If you have to talk in water, walk through the area that is not moving.  Use a stick or long pole to check the firmness of the ground in front of you.
  • Do not drive into flooded areas.  If floodwaters rise around your car, abandon the car and move to higher ground, when water is not moving or not more than a few inches deep.  You and the vehicle can be swept away quickly.  If your car is trapped in rapidly moving water, stay in the vehicle. If the water is rising inside the vehicle, seek refuge on the roof.
  • Do not camp or park your car along streams, rivers, creeks or other bodies of water.

FLOOD WARNING SYSTEM

Stay alert to weather conditions and forecasts for severe thunderstorms or flash flooding.  If a road is covered by water, turn around and find another, safer path to your destination!

 

Flood Watch	Flooding is possible
Flash Flood Watch	Flooding is possible with little or no warning.
Flood Warning	Flooding is imminent (it may take several hours/days to occur)
Flash Flood Warning	Flash flooding is imminent and precautions should be taken.

 

After the flood:

Your home has been flooded. Although floodwaters may be down in some areas, many dangers still exist. Here are some things to remember in the days ahead:

• Use local alerts and warning systems to get information and expert informed advice as soon as available.
• Avoid moving water.
• Stay away from damaged areas unless your assistance has been specifically requested by police, fire, or relief organization.
• Emergency workers will be assisting people in flooded areas. You can help them by staying off the roads and out of the way.
• Always play it safe. Additional flooding or flash floods can still occur. Listen for local warnings and information. If your car stalls in rapidly rising waters, get out immediately and climb to higher ground.
• Wait for authorities to advise that it is safe to return to your home.
• Roads may still be closed because they have been damaged or are covered by water. Barricades have been placed for your protection. If you come upon a barricade or a flooded road, please find another route.
• If you must walk or drive in areas that have been flooded.
  • Walk on firm ground. Moving water only 6 inches deep can sweep you off your feet. Standing water may be electrically charged from underground or downed power lines.
  • Flooding may have caused familiar places to change. Floodwaters often erode roads and walkways. Flood debris may hide animals and broken bottles, and can be very slippery. Avoid walking or driving through it.
• Be aware of areas where floodwaters have receded. Roads may have weakened and could collapse under the weight of motor vehicles.
• Stay out of any building if it is surrounded by floodwaters.
• Use extreme caution when entering buildings; there may be hidden damage, particularly in foundations.

Staying Healthy

A flood can cause physical hazards and emotional stress. You need to look after yourself and your family as you focus on cleanup and repair.

• Avoid floodwaters; water may be contaminated by oil, gasoline or raw sewage.
• Service damaged septic tanks, cesspools, pits and leaching systems as soon as possible. Damaged sewer systems are serious health hazards.
• Listen for news reports to learn whether the community’s water supply is safe to drink
• Clean and disinfect everything that got wet. Mud left from floodwaters can contain sewage and chemicals.
• Rest often and eat well.
• Keep a manageable schedule. Make a list and do jobs one at a time.
• Discuss your concerns with others and seek help. Contact Red Cross for information on emotional support available in your area.
• Douglas County Emergency Management Plan is written in consideration of the relevant hazards identified in the Douglas County Hazard Analysis and to address the four phases of emergency management. The purpose of the plan is to define, to the extent appropriate, the policies, roles and responsibilities for a local integrated emergency management system within the constraints of existing resources and operational capabilities. The Douglas County Emergency Management Plan contains both a broad conceptual framework (describing the policy and approach to emergency operations for use by local officials) and specific information and direction for managers.

Cleaning Up and Repairing Your Home

• Turn off the electricity at the main breaker or fuse box. That way, you can decide when your home is dry enough to turn it back on.
• Get a copy of the book Repairing Your Flooded Home which is available free from the American Red Cross or your state or local emergency manager. It will tell you:
  • How to enter your home safely.
  • How to protect your home and belongings from further damage.
  • How to record damage to support insurance claims and requests for assistance.
  • How to check for gas or water leaks and how to have service restored.
  • How to clean up appliances, furniture, floors and other belongs.

• The Red Cross can provide you with a cleanup kit: mop, broom, bucket, and cleaning supplies.
• Contact your insurance agent to discuss your claim.
• Listen to your radio for information on assistance that may be provided by the state or federal government or other organizations.
• If you hire cleanup or repair contractors, check references and be sure they are qualified to do the job. Be wary of people who drive through neighborhoods offering help in cleaning up or repairing your home.

Safety Tips in Spanish
 

Douglas County Zoning & Codes Department

Mailing Address:

• 3755 E 25th Street
• Lawrence, KS  66046
• Phone Number: 785-331-1343
• Fax Number: 785-842-1201

Office Hours:

Monday - Friday:  8:00 am to 5:00 pm

Email:

zoning@douglascountyks.org

Floodplain Information

To request information about floodplain on your property, please complete this form, "Request for Floodplain Information".

 

Information about how and what you need to know to obtain flood insurance.

What is an Elevation Certificate?

 

ADDITIONAL RESOURCES:

• Elevation Certificate Reference Guide
• Managing Floodplain Development in Approximate Zone A Areas-A Guide for Obtaining and Developing Base (1% or 100 year) Flood Elevations
• Additional information on Elevation Certificate (Elevation Certificate Made Easy)