Floodplain Information

Floodplain Development Permit Requirements

Any activity performed in the floodplain must have a floodplain development permit. This includes grading, filling, residential construction and commercial construction. To obtain a permit you must complete an application. Applications can be picked up at the Department of Building and Safety, or online using the form below. Complete and return the form to the Department of Building and Safety along with 3 sets of plans for the project. The plans must clearly show existing and proposed contours at the site with all elevations submitted in NAVD 1988 datum. You must also submit approvals of all other required permits such as the NOI or 404 permit with the floodplain permit.


Local Flood Hazard

Low lying areas in the City of Lincoln are subject to periodic flooding from Salt Creek and its tributaries. The most severe flooding has occurred in late spring and early summer as a result of snow melt, heavy thunderstorm rainfall, ice jams, or combinations of the above.

Flooding in the City of Lincoln is caused by 11 main sources: Salt Creek, Oak Creek, Middle Creek, Antelope Creek, Beal Slough, Haines Branch, Cardwell Branch, Elk Creek, Lynn Creek, Deadman's run, and Little Salt Creek. Flooding along Salt Creek and Oak Creek is of long duration with ample warning time prior to the peak. Little Salt Creek, Middle Creek, and Haines Branch have smaller drainage basins with a shorter flood duration and less warning time prior to the peak. Flooding along Antelope Creek, Beal Slough, Cardwell Branch, Elk Creek, Lynn Creek, Stevens Creek, and Deadman's Run is of short duration with little warning time prior to the peak.

Since 1900, 100 floods have been recorded along Salt Creek and Its tributaries in and near the City of Lincoln. Of those 17 were classified as major, 30 as moderate, and 49 as minor. The Salt Creek flood in May of 1950 resulted from a thunderstorm that dumped 11 inches of rainfall in a 6 hour period over the Salt Creek drainage basin. Nearly 20,000 acres were flooded and 9 people died. In Lincoln 600 homes, 80 commercial establishments, railroad yards, and other properties were flooded. Basin damages were estimated at 2.9 million dollars. If a repeat flood event of this magnitude were to occur it could result in greater damages and greater loss of life.

Local Flood Safety

Mitigation pays. It includes any activities that prevent an emergency, reduce the chance of an emergency happening, or lessen the damaging effects of unavoidable emergencies. Investing in mitigation steps now such as constructing barriers such as levees and purchasing flood insurance will help reduce the amount of structural damage to your home and financial loss from building and crop damage should a flood or flash flood occur.

Before a Flood

Find out if you live in a flood-prone area from your local emergency management office or Red Cross chapter. Ask whether your property is above or below the flood stage water level and learn about the history of flooding for your region. Learn flood warning signs and your community alert signals. Request information on preparing for floods and flash floods. If you live in a frequently flooded area, stockpile emergency building materials. These include plywood, plastic sheeting, lumber nails, hammer and saw, pry bar, shovels, and sandbags. Have check valves installed in building sewer traps to prevent flood waters from backing up in sewer drains. As a last resort, use large corks or stoppers to plug showers, tubs, or basins. Plan and practice an evacuation route. Contact the local emergency management office or local American Red Cross chapter for a copy of the community flood evacuation plan. This plan should include information on the safest routes to shelters. Individuals living in flash flood areas should have several alternative routes. Have disaster supplies on hand.

  • Flashlights and extra batteries
  • Portable, battery-operated radio and extra batteries
  • First aid kit and manual
  • Emergency food and water
  • Non-electric can opener
  • Essential medicines
  • Cash and credit cards
  • Sturdy shoes

Develop an Emergency Communication Plan

In case family members are separated from one another during floods or flash floods (a real possibility during the day when adults are at work and children are at school), have a plan for getting back together. Ask an out-of-state relative or friend to serve as the "family contact." After a disaster, it's often easier to call long distance. Make sure everyone in the family knows the name, address, and phone number of the contact person. Make sure that all family members know how to respond after a flood or flash flood. Teach all family members how and when to turn off gas, electricity, and water. Teach children how and when to call 9-1-1, police, fire department, and which radio station to tune to for emergency information. Learn about the National Flood Insurance Program. Ask your insurance agent about flood insurance. Homeowners policies do not cover flood damage.

During a Flood Watch

Listen to a battery-operated radio for the latest storm information. Fill bathtubs, sinks, and jugs with clean water in case water becomes contaminated. Bring outdoor belongings, such as patio furniture, indoors. Move valuable household possessions to the upper floors or to safe ground if time permits. If you are instructed to do so by local authorities, turn off all utilities at the main switch and close the main gas valve.Be prepared to evacuate.

During a Flood

If indoors: Turn on battery-operated radio or television to get the latest emergency information. Get your preassembled emergency supplies. If told to leave, do so immediately.

If outdoors: Climb to high ground and stay there. Avoid walking through any flood waters. If it is moving swiftly, even water 6inches deep can sweep you off your feet.

If in a car: If you come to a flooded area, turn around and go another way. If your car stalls, abandon it immediately and climb to higher ground. Many deaths have resulted from attempts to move stalled vehicles.

During An Evacuation

If advised to evacuate, do so immediately. Evacuation is much simpler and safer before flood waters become too deep for ordinary vehicles to drive through. Listen to a batter-operated radio for evacuation instructions. Follow recommended evacuation routes--shortcuts may be blocked. Leave early enough to avoid being marooned by flooded roads.

After A Flood

Flood dangers do not end when the water begins to recede. Listen to a radio or television and don't return home until authorities indicate it is safe to do so. Remember to help your neighbors who may require special assistance--infants, elderly people, and people with disabilities. Inspect foundations for cracks or other damage. Stay out of buildings if flood waters remain around the building. When entering buildings, use extreme caution. Wear sturdy shoes and use battery-powered lanterns or flashlights when examining buildings. Examine walls, floors, doors, and windows to make sure that the building is not in danger of collapsing. Watch out for animals, especially poisonous snakes, that may have come into your home with the flood waters. Use a stick to poke through debris. Watch for loose plaster and ceilings that could fall. Take pictures of the damage--both to the house and its contents for insurance claims.

Look for:

  • Fire hazards
  • Broken or leaking gas lines
  • Flooded electrical circuits
  • Submerged furnaces or electrical appliances
  • Flammable or explosive materials coming from upstream
  • Throw away food--including canned goods--that has come in contact with flood waters.
  • Pump out flooded basements gradually (about one-third of the water per day) to avoid structural damage.
  • Service damaged septic tanks, cesspools, pits, and leaching systems as soon as possible. Damaged sewage systems are health hazards.

Inspecting Utilities In a Damaged Home

Check for gas leaks. If you smell gas or hear blowing or hissing noise, open a window and quickly leave the building. Turn off the gas at the outside main valve if you can and call the gas company from a neighbor's home. If you turn off the gas for any reason, it must be turned back on by a professional. Look for electrical system damage--If you see sparks or broken or frayed wires, or if you smell hot insulation, turn off the electricity at the main fuse box or circuit breaker. If you have to step in water to get to the fuse box or circuit breaker, call an electrician for advice. Check for sewage and water lines damage--If you suspect sewage lines are damaged avoid using the toilets and call a plumber. If water pipes are damaged, contact the water company and avoid the water from the tap. You can obtain safe water by melting ice cubes.

Flood Warning System

The most likely times when floods will occur are in the rainy months from April to August. Residents should tune their radios and TVs to local stations for weather advisories. The following stations will broadcast local weather warnings:

Radio

  • KFOR 1240 AM
  • KFRX 106.3 FM
  • KRKR 95.1 FM
  • KLMS 1480 AM

Television

  • KLKN Channel 8
  • KOLN 10/11

The Lincoln-Lancaster County Department of Emergency Management stays in direct contact with the National Weather Service. In case of a flood threat they have a network of warning gages and 39 spotters monitoring current local conditions. If a flood threat is detected they will interrupt local cable to deliver the warning message. In case of an evacuation warning, local police and fire personnel will help facilitate the process. Even with the warning system it is still good to know your evacuation route, and remember that if you feel unsafe at any time you should evacuate and go to higher ground.

Drainage System Maintenance

Dumping in the streams, ponds, and the drainage system in Lincoln is strictly prohibited according to Section 24.38.060 of the Lincoln Municipal Code. Trash, leaves, dirt, and any liquid other than water are included under this section and should under no circumstances be dumped in sewers, streams or lakes. Improper dumping can be harmful because all of the storm water drains and streams eventually run together into streams and lakes such as Holmes Lake. Any pollutants or other items dumped into the systems will contaminate the system and may plug up the storm sewer systems which could result in flooding. This effect can be seen at Holmes Lake by looking at the water quality and amount of sediment that has collected in the lake. On some of the inlets to the storms drains you will find an anti-dumping logo glued or stamped into the concrete. These are to serve as a reminder to protect our natural resources and to protect yourself from flooding due to drain blockage. If you have questions call the Health Department or the Public Works and Utilities Department.

Flood Insurance

In 1968, Congress created the National Flood Insurance Program (NFIP) in response to the rising cost of taxpayer funded disaster relief for flood victims and the increasing amount of damage caused by floods. The NFIP makes Federally-backed flood insurance available in communities that agree to adopt and enforce floodplain management ordinances to reduce future flood damage. National Flood Insurance is available in more than 19,000 communities across the United States and its territories. The NFIP is managed by the Federal Emergency Management Agency Federal Insurance and Mitigation Administration and Mitigation Directorate. The Federal Insurance and Mitigation Administration manages the insurance component of the NFIP, and works closely with FEMA's Mitigation Directorate, which oversees the floodplain management and mapping components of the Program. The NFIP, through partnerships with communities, the insurance industry, and the lending industry, helps reduce flood damage by nearly $800 million a year. Further, buildings constructed in compliance with NFIP building standards suffer approximately 80 percent less damage annually than those not built in compliance. And, every $3 paid in flood insurance claims saves $1 in disaster assistance payments. The NFIP is self-supporting for the average historical loss year, which means that operating expenses and flood insurance claims are not paid for by the taxpayer, but through premiums collected for flood insurance policies.

Top 10 Facts Every Consumer Needs to Know About The National Flood Insurance Program (NFIP)

  1. Everyone lives in a flood zone. You don't need to live near water to be flooded. Floods are caused by storms, melting snow, hurricanes, and water backup due to inadequate or overloaded drainage systems, dam or levee failure, etc.
  2. Flood damage is not covered by homeowners policies. You can protect your home, business, and belongings with flood insurance from the National Flood Insurance Program. You can insure your home with flood insurance for up to $250,000 for the building and $100,000 for your contents.
  3. You can buy flood insurance no matter what your flood risk is. It doesn't matter whether your flood risk is high, medium, or low, you can buy flood insurance as long as your community participates in the National Flood Insurance Program. And, it's a good idea to buy even in low or moderate risk areas: almost 25 percent of all flood insurance claims come from low- to moderate-risk areas.
  4. There is a low-cost policy for homes in low- to moderate-risk areas. The Preferred Risk Policy is available for just over $100 a year. You can buy up to $250,000 of coverage for your home and $60,000 of coverage for your contents.
  5. Flood insurance is affordable. The average flood insurance policy costs a little more than $300 a year for about $100,000 of coverage. In comparison, a disaster home loan can cost you more than $300 a month for $50,000 over 20 years.
  6. Flood insurance is easy to get. You can buy NFIP flood insurance from private insurance companies and agents; call yours today! You may be able to purchase flood insurance with a credit card.
  7. Contents coverage is separate, so renters can insure their belongings too. Up to $100,000 contents coverage is available for homeowners and renters. Whether you rent or own your home or business, make sure to ask your insurance agent about contents coverage. It is not automatically included with the building coverage.
  8. Up to a total of $1 million of flood insurance coverage is available for non-residential buildings and contents. Up to $500,000 of coverage is available for non-residential buildings. Up to $500,000 of coverage is available for the contents of on-residential buildings.
  9. There is usually a 30-day waiting period before the coverage goes into effect. Plan ahead so you're not caught without flood insurance when a flood threatens your home or business.
  10. Federal disaster assistance is not the answer. Federal disaster assistance is only available if the President declares a disaster. More than 90 percent of all disasters in the United States are not Presidentially declared. Flood insurance pays even if a disaster is not declared.

Property Protection Measures

Avoiding Flood Damage: a Checklist for Homeowners

Federal Emergency Management Agency

Are you looking for ways to protect your home from flooding? There are many things you can do, depending on the flood hazard in your area, the characteristics of your property, and the zoning and building codes in your community. Some methods are fairly simple and inexpensive; others will require a professional contractor.

This homeowner's checklist will help you become familiar with what you can do. For more information about the costs and benefits of each method, talk to a professional builder, architect or contractor. You should also ask your building department about building permit requirements.

Do you know your flood risk?

Call your local emergency management office, building department or floodplain management office for information about flooding. Ask to see a flood map of your community. There may be a projected flood elevation for your neighborhood. This information will help you determine how much water is likely to come in.

Do you have enough flood insurance?

Even if you have taken steps to protect your home from flooding, you still need flood insurance if you live in a floodplain. Homeowners' policies do not comer flood damage, so you will probably need to purchase a separate policy under the National Flood Insurance Program(NFIP).

It takes 30 days for a flood policy to take effect. This is why you need to purchase flood insurance before flooding occurs. If your insurance agent is unable to write a flood policy, call 1-800-638-6620 for information.

Is the main electric switch box located above potential flood waters?

The main electric panel board (electric fuses or circuit breakers) should be at least 12" above the projected flood elevation for your home. The panel board height is regulated by code. All electrical work should be done by a licensed electrician.

Are electric outlets and switches located above potential flood waters?

Consider elevation all electric outlets, switches, light sockets, baseboard heaters and wiring at least 12" above the projected flood elevation for your home.

You may also want to elevate the electric service lines (at the point they enter your home) at least 12" above the projected flood elevation.

In areas that could get wet, connect all receptacles to a ground fault interrupter (GFI) circuit to avoid the risk of shock or electrocution.

Have electrical wiring done by a licensed electrician.

Are the washer and dryer above potential flood waters?

For protection against shallow flood waters, the washer and dryer can sometimes be elevated on masonry or pressure-treated lumber at least 12" above the projected flood elevation. Other options are moving the washer and dryer to a higher floor, or building a floodwall around the appliances.

Are the furnace and water heater above potential flood waters?

The furnace and water heater can be placed on masonry blocks or concrete at least 12" above the projected flood elevation, moved to inside a floodwall or moved to a higher floor. (You have more options for protecting a new furnace. Ask your utility about rebates for new energy efficient furnaces. The rebate plus the savings in fuel costs could make the purchase feasible.)

Furnaces that operate horizontally can be suspended from ceiling joists if the joists are strong enough to hold the weight. Installing a draft-down furnace in the attic may be an option if allowed by local codes. Some heating vents can be located above the projected flood elevation.

Outside air conditioning compressors, heat pumps or package units (single units that include a furnace and air conditioner) can be placed on a base of masonry concrete or pressure treated lumber.

All work must conform to state and local building codes.

Is the fuel tank anchored securely?

A fuel tank can tip over or float in a flood, causing fuel to spill or catch fire. Cleaning up a house that has been inundated with flood waters containing fuel oil can be extremely difficult and costly.

Fuel tanks should be securely anchored to the floor. Make sure vents and fill line openings are above projected flood levels.

Propane tanks are the property of the propane company. You'll need written permission to anchor them. Ask whether the company can do it first.

Be sure all work conforms to state and local building codes.

Does the floor drain have a float plug?

Install a floating floor drain plug at the current drain location. If the floor drain pipe backs up, the float will rise and plug the drain.

Does the sewer system have a backflow valve?

If flood waters enter the sewer system, sewage can back up and enter your home. To prevent this, have a licensed plumber install an interior or exterior backflow valve. Check with your building department for permit requirements.

You may have other options for avoiding flood damage depending on your needs and financial resources. These include building drainage systems around the property, sealing openings such as low windows, building levees, constructing exterior floodwalls around basement doors and window wells, improving exterior walls, elevating buildings above projected flood levels and relocating buildings away from floodplains.

For more information talk to a professional builder, architect or contractor. Ask your building department about building permit requirements.

Natural and Beneficial Fuctions of the Floodplain

Surface waters, their floodplains, and their watersheds must be viewed as parts of one ecological system. This system exists in a state of dynamic equilibrium. If one of the parts of the system is disturbed, the entire system will readjust toward a new equilibrium. This is true of coastal, river, and lake systems. The geological and biological effects of the system's readjustments toward its new equilibrium are often felt far from the original site of the disturbance and can last for decades. For this reason, if for no other, floodplain development and modification should be viewed with caution and with careful assessment of the potential adverse impacts on natural values.

Floodplains in their natural or relatively undisturbed state provide three broad sets of natural and beneficial resources and hence resource values:

  1. Water resources values including natural moderation of floods, water quality maintenance, and groundwater recharge.
  2. Living resources values including large and diverse populations of plants, and animals.
  3. Cultural resource values including historical archeological, scientific, recreational, and esthetic sites in addition to sites generally highly productive for agriculture, aquaculture, and forestry where these uses are compatible with natural values.

Water Resources Values

Natural Flood Storage and Conveyance

The characteristics of the floodplain and of flooding are closely interdependent. Floods shape floodplain topography and soils and influence ecology. In turn, the physical characteristics of the floodplains shape flood flows. Except in narrow, steep valleys and areas of coastal bluffs, floodplains provide a broad area to spread out and temporarily store flood waters. This reduces flood peaks and velocities. and the potential for erosion. In their natural vegetated state, floodplains slow the rate at which incoming overland flow reaches the main water body. They also accommodate the natural phenomena of stream meander and beach drifting.

Water Quality Maintenance

Floodplains serve important function in protecting the physical, biological, and chemical integrity of water. Water that runs off quickly over the surface, as on a barren floodplain, is capable of carrying with it large amounts of sediment and debris to the main water body. A vegetated floodplain, however, slows the surface runoff, causing it to drop most of its sediment load on the floodplain. Vegetation also filters incoming flood waters. Much of the sediment origination on the land drops out as well as some of the scoured from the channel band and bed. This filtering process may add rich nutrients to the floodplain soil. However, excess nutrients entering the stream in runoff can accelerate eutrophication in downstream lakes and reservoirs.

Groundwater Recharge

The natural floodplain has surface conditions favoring local ponding and flood detention, plus subsurface conditions favoring infiltration and storage. The slowing of runoff across the floodplain allows additional time for the runoff to infiltrate and recharge available groundwater aquifers, when there is unused storage capacity. The slowing of runoff provides the additional absorption, and aerobic and anaerobic biological action. This value extends into nonflood periods as groundwater discharge acts to naturally regulate the flow in a river or the level of a pond. In other words, during periods of abundant water, the water can enter the groundwater system whenever there is available capacity rather than contribute to seasonal flood peaks; during low flow periods, the water flows from higher ground-water system into lower surfaces waters, so that the frequency and duration of extremely low flows is reduced.

Living Resources and Habitat Values

The Nation's coastal and riverine floodplains support large and diverse populations of plants and animals. In addition they provide habitat and critical sources of energy and nutrients for organisms in adjacent and downstream terrestrial and aquatic ecosystems. The wide variety of plants and animals supported directly and indirectly by floodplains constitutes an extremely valuable, renewable resource important to economic welfare, enjoyment, and physical well being.

The floodplain is biologically important because it is the place where land and water meet and the elements of both terrestrial and aquatic ecosystems mix. The detritus provided by headwater woodlands frequently provides the major source of nutrients and energy that sustain production in woodland streams. Nutrients and energy that enter these upstream areas find their way far downstream into larger rivers and lake via the aquatic food chain. Shading of the stream by floodplain vegetation moderates water temperatures; roots and fallen trees provide in stream habitat, and near stream vegetation filters runoff, removing harmful sediments and buffering pollutants, to further enhance in stream environments.

Cultural Resources Values

Floodplains contain cultural resources important to the Nation and to individual localities. Native American settlements and early cities located along the coasts and rivers in order to have access to water supply, waste disposal, water transportation, and transshipment. Consequently, floodplains include most of the Nation's earliest archeological and historical sites. In addition to their historical richness, floodplains may contain invaluable resources for scientific research. For example, where floodplains contain unique ecological habitats, they make excellent areas for scientific study. The bedrock geology of the area may be exposed in the floodplain. Floodplains may provide open space community resources. In urban communities they may provide green belt areas to break urban development monotony, absorb noise, clean the air, and lower temperatures. Floodplain parks can also serve as nature study centers and laboratories for outdoor learning experiences.

Because of their scenic value and locational and other characteristics, some of which are unique, floodplains are attractive for recreation. Water-oriented sports, boating, and swimming can be based in a natural floodplain park which also may be suitable for hiking and camping. Floodplain wildlife resources can be managed for observation as well as for recreational hunting and fishing. Finally natural floodplains are valued as constituents of the "wilderness experience" important in the American culture.