Flooding
Floodplain Management
Living and Building by Streams
Floods
Floods are natural events that occur in response to heavy rains and snow melt. Under flood conditions, waters rise, often overflow stream banks, and spill onto adjoining low-lying land.
Historically, streamside landowners have responded to floods by making straighter, deeper stream channels to carry the water downstream as fast as possible. However, this approach actually can cause more damage in the long run, since it increases stream power and causes severe erosion and damage to nearby structures.
Rather than fighting against a stream, it is more practical to work with the natural landscape to avoid damages by reducing the speed and volume of flood waters.
What is a Floodplain?
Floodplains are low-lying lands next to rivers and streams. When left undisturbed in a natural state, floodplains store water and dissipate floods without adverse impacts on humans, buildings, roads and other infrastructure. Without floodplain access, which serves the essential purposes of slowing floodwaters and storing sediment, stream banks are subjected to the full power of flood flows, leading to extensive damage and erosion.
Functions of Healthy Floodplains
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Flood waters can spread over a large area in floodplains that have not been encroached upon. This reduces flood velocities and provides flood storage to reduce peak flows downstream.
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Water quality is improved in areas where natural floodplain cover acts as a filter to remove impurities from runoff and overbank flows.
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Natural floodplains moderate water temperature, reducing the possibility of adverse impacts on aquatic plants and animals.
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Floodplains can act as recharge areas for groundwater, and reduce the frequency and duration of low flows of surface water.
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Floodplains provide habitat for diverse species of flora and fauna, some of which cannot live anywhere else. They are particularly important as mating and feeding areas.
Factors that Affect a Healthy Floodplain and Increase Flood Damage
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The removal of stabilizing vegetation around stream banks and rivers. -
Erecting structures that deflect or inhibit the flow of floodwaters. This modifies flow paths and can spread flooding problems and erosion.
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Constructing bridges, culverts, buildings, and other structures that encroach on the floodplain. These developments reduce the storage area available for floodwaters.
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Building drainage systems that feed stormwater quickly into the receiving body.
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Straightening meandering watercourses to hasten drainage. This transfers flooding problems downstream and also alters habitat.
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Filling and dumping in floodplains. Floodwaters can transport this debris, which may interfere with the movement of the floodwater causing increased flood elevations.
Encroachment & Loss of Floodplains
Historically, floodplains were the first lands developed. Whether for transportation, farming, power production, or simply for the use and enjoyment of living by a stream, streamside property is still highly desirable for developers. However, it is a fact of life that floods occur along streams and rivers; floods are a natural and unavoidable. On the other hand, loss of life, property, personal items, and our homes is an avoidable situation.
The Cost of Building on the Floodplain
Average annual flood losses in the United States are currently estimated at $6 billion. This is a four-fold increase over the past century, and is a doubling in terms of dollars of damage per capita. The general trend is for flood losses to increase every decade due to increasing development in the floodplain, open spaces, and wetlands. As a result, floods have become far larger and more frequent.
Local Example: Why to Avoid Building in the Floodplain
The downtown area of Phoenicia, NY (Ulster County) is built almost entirely in active floodplains of the Stony Clove and Esopus Creek.This fact, coupled with an undersized bridge on Main St. that spans the Stony Clove, causes intense, damaging flooding during rain events. The video below shows the flooding in Phoenicia during the December 1, 2010 event (a 10-year flood).
General Advice for Floodplain Management
DO:
…Remove blockages such as large trees or debris that are underneath or against a bridge or culvert.
…Work with your neighbors to find mutually supportive solutions that do not harm property upstream or downstream.
…Contact Greene County Soil & Water to assist with design work and restoration.
…Contact state or federal resource agency about obtaining the required permits to use machinery in a stream or along a stream bank.
DON’T:
…Attempt to bulldoze or dig out the stream. Dredging a stream speeds up flood waters and increases erosion up and downstream of the site. Dredging also can severely damage bridges and roads.
…Remove all large rocks and boulders from a stream. Gravel bars, rocks and boulders all help reduce flood power, keep a stream stable and provide valuable aquatic habitat.
…Place loose gravel and material on stream banks or build up artificial barriers, debris piles or levees. This will prevent the stream from spreading out on the floodplain and will increase water velocities and associated flooding downstream.
…Assume that any permit applies to flood response work in or near a stream. Call Greene County Soil & Water to learn the rules for permits.
…Allow unqualified contractors to work on your land. You may be held responsible for any permit violations or damage caused to neighboring properties.
Additional Resources
Flood Preparedness Information
National Flood Insurance Program
Post-Flood Emergency Stream Intervention Manual (4 Mb pdf)
Association of State Floodplain Managers
DEC Floodplain Management Information
DEC Floodplain Development and Floodway Guidance
Beyond Floodplain: LID Techniques for Upland Management of Floodplains
Building Activites in the NYC Watershed that Require a Permit
FEMA Model Flood Damage Prevention Ordinance
National Flood Insurance Program
What is the National Flood Insurance Program?
The National Flood Insurance Program is a federal program created in 1968 to provide flood insurance to people who live in areas with the greatest risk of flooding, called Special Flood Hazard Areas. The program provides an alternative to disaster assistance and reduces the escalating costs of repairing damage to buildings and their contents caused by floods. The program provides flood insurance, while at the same time encouraging the sensible management and use of floodplains to reduce flood damage.
The NFIP offers flood insurance to homeowners, renters, and business owners, provided their communities use the program's strategies for reducing flood risk, including adopting and enforcing floodplain management ordinances to reduce future flood damage. Community participation in the NFIP is voluntary. However, flood insurance and many kinds of federal disaster assistance are not available in communities that do not participate in the program. Check with your local town hall or contact Greene County Soil & Water Conservation District to find out if your community participates in the NFIP.
NFIP Floodplain Maps
The NFIP floodplain maps represent an estimate of the risk of flooding in a certain area, and specifically show the extent of the floodplain affected by the base flood or “100-year flood”. This is the severity of flood that has a 1% chance of occurring in any given year, and the base floodplain is called the Special Flood Hazard Area. Development in the SFHA is regulated by the local government. Check your community's flood hazard ordinance, or contact Greene County Soil & Water Conservation District to see these restrictions.
View floodplain maps for your area:
1. Read this tutorial (1 Mb) on obtaining Floodplain Insurance Rate Maps through FEMA’s FIRMette Desktop viewer. (Greene County FIRM index)
2. Visit www.msc.fema.gov to find your Floodplain Insurance Rate Map
NFIP Community Rating System
The National Flood Insurance Program's (NFIP) Community Rating System (CRS) is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements.
As a result, flood insurance premium rates are discounted to reflect the reduced flood risk resulting from the community actions meeting the three goals of the CRS:
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Reduce flood losses
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Facilitate accurate insurance rating
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Promote the awareness of flood insurance
For CRS participating communities, flood insurance premium rates are discounted in increments of 5%; i.e., a Class 1 community would receive a 45% premium discount, while a Class 9 community would receive a 5% discount (a Class 10 is not participating in the CRS and receives no discount). The CRS classes for local communities are based on 18 creditable activities, organized under four categories:
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Public Information
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Mapping and Regulations
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Flood Damage Reduction
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Flood Preparedness
Visit the CRS Resource Center to view documents that explain the CRS and provide all of the tools needed to apply for participation.
Additional Resources
Flood Preparedness Information
Floodplain Management Information
National Flood Insurance Program
Post-Flood Emergency Stream Intervention Manual (4 Mb pdf)
Association of State Floodplain Managers
DEC Floodplain Management Information
DEC Floodplain Development and Floodway Guidance
Beyond Floodplain: LID Techniques for Upland Management of Floodplains
Building Activites in the NYC Watershed that Require a Permit
FEMA Model Flood Damage Prevention Ordinance
Flood Preparedness
What to do Before and After the Flood
Introduction to Floods
Floods occur when runoff from rain or snowmelt exceeds the capacity of rivers, stream channels, or lakes and overflows onto adjacent land. Throughout history, floods have claimed uncounted human lives and devastated property, even destroying cities. Yet people continue to settle and build in floodplains, increasing the risk of property damage and loss of life.
Prepare: Know What To Do Quickly in an Emergency
During floods and other natural disasters, having a plan and supplies ready can make the difference between safety and life-threatening situations. You can also feel safer and more confident knowing what to do during an emergency. Many websites have great guides for preparedness plan and survival kit checklists: www.ready.gov and www.floodsmart.gov are two good sites.
Sign up for NY-ALERT
By signing up for NY-Alert, you can receive warnings and emergency information via the web, your cell phone, email and other technologies. NY-ALERT is a tool to provide you with critical information when you may need it most.
Signing up for NY Alert is free. Your information is protected and never shared with any one else. You can modify what type of information you receive or unsubscribe at any time.
Information sent by NY-ALERT includes severe weather warnings, significant highway closures, hazardous materials spills, and many other emergency conditions. Additionally you will find information regarding response actions being taken by local and state agencies and protective actions that you should take to protect you, your family and your property.
To sign up, go to www.nyalert.gov.
If a flood is likely in your area, you should:
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Listen to the radio or television for information
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Check NY ALERT (see above)
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Be aware that flash flooding can occur. If there is any possibility of a flash flood (e.g. a flash flood warning for your location), move immediately to higher ground. Do not wait for instructions to move.
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Secure your home. If you have time, bring in outdoor furniture. Move essential items to an upper floor.
Evacuation Checklist
If there is time, move important papers, television sets, computers, stereo equipment and easily moveable appliances such as a microwave oven to the upper floors of your home.
If your basement floods before you have a chance to shut off electric or you suspect a natural gas buildup, do not enter the basement. There is the possibility of electric shock if any electrical wires are touching the water. Contact your electric company as soon as possible.
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Turn off all electrical appliances. Do not touch electrical equipment if you are wet or standing in water.
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Turn off the electricity at the main fuse or circuit breaker
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Turn off water at the main valve.
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Turn off propane gas service. Propane tanks often become dislodged in emergency situations.
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Leave natural gas on. Unless local officials advise otherwise, leave natural gas on because you will need it for heating and cooking when you return home. If you turn the gas off, a licensed professional is required to turn it back on and it may take weeks for a professional to respond.
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Drain your plumbing if it is likely that the temperature in your house will go below freezing. Shut off the water service valve. Then turn on the highest and lowest hot and cold water taps in the house to drain your system. Also, flush toilets and remove water from lower bowl to prevent freezing damage. Leave all taps open until you return.
Returning Home After a Flood
Before You Enter Your Home
Check for loose power lines, gas leaks, and structural damage. If you have any doubts about safety, have your residence inspected by a qualified building inspector or structural engineer before entering.
Do not enter if:
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You smell gas.
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Floodwaters remain around the building.
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Your home was damaged by fire and authorities have not declared it safe.
Going Inside Your Home:
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Natural Gas: If you smell gas or hear a hissing or blowing sound, open a window and leave immediately and call the gas company from a neighbor’s residence.
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Electricity: Do not touch electrical components if you are wet or standing in water. Turn off electricity and unplug appliances until wires are dry. Have appliances inspected before use.
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Water: Flood waters may be contaminated with fecal matter and bacteria. Be aware of hygiene - wash hands and keep cuts and sores clean and use antibiotic ointment. Do not let children play in flood water. Check media for boil water advisories.
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Prevent Mold Growth: Mold can cause disease and allergies. Remove standing water, all wet materials, and ventilate with fans and use dehumidifiers. If mold has already grown in the house, consult a professional. Be careful of mixing household cleaners as some combinations can produce very toxic fumes.
How to Avoid Flood Damage to Your Property
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Avoid building in a floodplain unless you elevate and reinforce your home. -
Do not mow to the stream. Maintain a wide buffer of trees and shrubs to slow water and prevent erosion.
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Elevate the furnace, water heater, and electric panel if susceptible to flooding.
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Install "check valves" in sewer traps to prevent flood water from backing up into the drains of your home.
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Seal walls in basements with waterproofing compounds to avoid seepage.
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Secure propane tanks and other objects that could be carried away in flood waters.
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Install stormwater management systems around buildings. Keep ground sloped away from your house.
Have you Sustained Flood Damage to Your Property?
Please fill out this form if you live in Greene County and experienced property damage as a result of a recent flood event, and fax or mail it to the Greene County Department of Emergency Services, or email it to John P. Farrell at
Additional Resources
Floodplain Management Information
Greene County Department of Emergency Services
National Flood Insurance Program
Post-Flood Emergency Stream Intervention Manual (4 Mb pdf)
Factsheets from Cornell Cooperative Extension of Greene County
- Mold Removal Guidelines for Your Flooded Home
- Septic Systems - What to Do After a Flood
- Dealing with Mold and Mildew in Your Flood-Damaged Home
- Floods: First Entry of a Flooded Home - What to Do
- Chainsaw Safety for Homeowners
- Flood Safety After a Flood
- Drying Out the House
- Certified Water Testing Laboratories
- Guidelines for Handling Water-Damaged Electrical Equipment
- Flood and Storm Damaged Crops
- Handling Flood Damaged Crops
- Flood Safety Advice to Commercial Growers Regarding Flooded Crops
- Woodland Owner and Maple Producer Response to Hurricane Irene
- Cleaning Your Flooded or Water-Damaged Home
- A Flood of Emotions
- Flooded Gardens
- Flood Recovery - Restoring Water Wells
- Cleaning and Disinfecting Your Home After the Flood
FEMA Publications
After a Flood: The First Steps (141 Kb) FEMA Document L-198.
Information for homeowners on preparedness, safety, and recovery from a flood
Homeowner’s Guide to Retrofitting: Six Ways to Protect Your House from Flooding (1 Mb) FEMA Document L-235.
A brochure about obtaining information about how to protect your home from flooding.
Above the Flood: Elevating Your Floodprone House (4.9 Mb) FEMA Document 347.
This publication is intended for builders, code officials and homeowners.
Flooding
Flood Preparedness Information
Learn how to prepare your family and home for a flood, and what to do after the storm is over.
Floodplain Management Information
Learn about floodplains, their role in flood protection, and proper floodplain management.
National Flood Insurance Program
Learn about insuring your property against flood damage through FEMA's National Flood Insurance Program.
Historical Floods in Greene County and the Role of the District
In August 1955 and September 1960, the Mountaintop region of Greene County was hit by two devastating floods. In each instance, the flood events were associated with the remains of major hurricanes which had pushed inland as tropical storms. These flood storms produced very significant damage. In 1961, the Greene County Soil & Water Conservation District was formed specifically to facilitate the development of a flood protection project on the Batavia Kill in the Town of Windham.
Since that time, the District has continued to place flood response and mitigation as a high priority. Whether it is facilitating communities with pre-disaster planning, or coordinating mitigation construction projects, the GCSWCD is an active participant in flood mitigation in Greene County.
The GCSWCD is a member of:
- NYSDEC Citizens Flood Mitigation Advisory Committee
- SEMO Project Impact Review Board
- SEMO Hazard Mitigation Grant Program Project Review Board
- NYS Disaster Prepardness Commission Mitigation Advisory Committee
- Greene County Hazard Mitigation Coordinator
- NYS Association of Floodplain and Stormwater Managers
- Batavia Kill Watershed Protection District Board of Directors