- Introduction to Flood Management in Prince George's County
- Local Flood Hazards, Mapping, and History of Flooding
- FEMA Website
- Flood Insurance Rate Maps and Flood Insurance (NFIP, CRS, CTC, FIRMs, LOMA/LOMR)
- FEMA Floodplain Map of Prince George's County
- Preliminary Flood Insurance Rate Map
- Elevation Certificates
- Known Floodprone Structures
- Flood Warning Systems
- Countywide Flood Damage Reduction Strategies
- Property Protection Projects (retrofitting, drainage, protecting against high wind, etc.), and Substantial Improvement/Damage
- GIS and Mapping Components
- Watershed Studies
- Drainage Maintenance
- Public Outreach
- Floodplain Directory of Information Services
- Hurricane Season Special Warnings
- Disaster Do’s and Don’ts
- Disasters - Prepare & Plan
- Frequently Asked Questions (FAQs)
- Download Flooding Brochure (PDF)
Introduction to Flood Management in Prince George's County
A floodplain is an integral part of the stream system. It provides storage capacity for high flows, helps reduce the erosive power of the stream during a flood, reduces the discharge of sediment during high flow periods and helps flood waters to move downstream. Floodplains also offer opportunities for wildlife habitat which can increase the biotic diversity of a stream. The 100-year floodplain is that land area adjoining the stream that has a 1% or greater probability of flooding in any given year. Floodplains provide a stream with buffer and water quality benefits as well.
It is the policy of the Prince George's County Government to preserve the 100-year floodplain as part of the natural system of a stream, and to further preserve it in a natural state in order to provide adequate storage for flood waters and sufficient carrying capacity to safely move flood waters downstream. Where existing structures in the 100-year floodplain cannot be protected in an environmentally sensitive and cost effective manner, the County may offer to acquire them to reduce the potential for property damage and eliminate potential obstruction of flood waters. Future development is regulated within the ultimate 100-year floodplain. Prince George's County utilizes ultimate land-use conditions hydrology to determine flood discharges and to generate flood elevations for areas of the County under growth and development. Ultimate conditions hydrology reflects projected land-use conditions based on a community’s zoning maps and/or comprehensive land-use plans.
Prince George'’s County has, through the Maryland-National Capital Park and Planning Commission, established a policy to acquire stream valley parks throughout the County. Stream valley park acquisition permits public ownership of the floodplain, thus eliminating pressure for private development and providing recreational opportunities. Stream valley parks will continue to be an important component of the County’s recreation, open space and flood management programs.
Flood Management for Prince George's County is guided by
the following goals:
- Reduce or eliminate existing flood hazards;
- Prevent future flood hazards from developing;
- Reduce the economic losses associated with flooding
- Provide for expanded recreational and aesthetic opportunities in the County;
- Restore, preserve and enhance environmental quality
wherever possible; and
- Improve the quality of life in Prince George's County.
The Floodplain Ordinance was adopted by the County Council in April of 1989 and amended in 1993,
2000, and 2011. The Prince George's County Floodplain Ordinance is modeled after an ordinance suggested by the Maryland Department of the Environment (MDE). The Federal Emergency Management Agency (FEMA) contracted with MDE to review local floodplain ordinances to assure that they met FEMA requirements for eligibility for flood insurance.
The ordinance generally discourages filling or construction in the floodplain, but allows for a variance under certain circumstances, for example, to meet an important public need. Where filling is needed within the floodplain, an equal volume of compensatory storage must be provided. Furthermore, an impact study is needed to ensure that the floodplain elevation will not be increased. The ordinance also contains requirements for the protection of buffers, wetlands and other natural features associated with the floodplain.
Prince George's County has been participating in FEMA’s National Flood Insurance Program (NFIP) since 1972. The current effective Flood Insurance Rate Map (FIRM) can be reached by clicking on the FEMA
Floodplain Map of Prince George's County link. On September
30, 2010, FEMA issued preliminary updates to the Flood Insurance Study and Flood
Insurance Rate Map for Prince George’s County. To access the preliminary study
and map, please click on the following link:
Preliminary Flood Insurance Rate Map.
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Local Flood Hazards, Mapping, and History of Flooding
All waterways and bodies of water are subject to flooding – a condition that occurs when the volume of water exceeds the capacity of the waterway channels or when tidal waters are pushed inland by coastal storms:
• Riverine or nontidal bodies of water are those that drain upland areas and are not influenced by coastal and tidal processes. In addition to rivers, nontidal bodies of water include streams and creeks and other small flowing waters. Flooding can also occur in localized low spots, even if the area is not adjacent to a body of water.
• Coastal flooding affects tidal bodies of water, including the tidal reaches of the Potomac River and the Patuxent River in Prince George’s County. The Potomac River is subject to tidal flooding along its entire length in the County, and the Patuxent River is subject to tidal flooding up to the confluence of Western Branch.
The Prince George's County Department of Environmental Resources (DER) recognizes and manages riverine flood hazard areas that are designated in two ways:
• Areas identified as vulnerable to flooding from the 1% annual chance flood (100-year floodplain) as shown on the County’s Flood Insurance Rate Map (FIRM) prepared by FEMA's National Flood Insurance Program (NFIP); and
• Other flood maps based on studies prepared by the County to evaluate the impact of future development. These maps often include areas not studied by the NFIP.
The first Flood Insurance Study and FIRM for the County were dated August 4, 1972 and prepared by the U.S. Department of Housing and Urban Development (a precursor agency to FEMA). Since that time, updates to the FRIM have been completed. The most recently revised and reprinted map panels are dated September 6, 1996. Also, note that FEMA published a preliminary county-wide FIRM for the County on September 30, 2010.
Starting in the 1980s, DER began to obtain State grants and use County funding to prepare more up-to-date watershed studies to delineate floodplains. The County's studies and maps, prepared with detailed base map data and detailed engineering models, account for future watershed development. They also are the basis for the State’s regulation of nontidal waterways. Watershed studies have been prepared for the following bodies of water:
- Piscataway Creek (April 1986);
- Henson Creek (April 1986);
- Western Branch of the Patuxent River (revised August 1991);
- Tinkers Creek (June 1979);
- Anacostia River (October 1993);
- Folly Branch (February 1995);
- Collington Branch (June 1985);
- Bald Hill Branch (April 1992);
- Southwest Branch (December 1992);
- Charles Branch (June 1991);
- Oxon Run (June 1991); and
- Beaverdam Creek (August 1995).
The figure below shows the extent of flooding as depicted on the latest FEMA FIRM. For more information on FEMA FIRM, how to locate your property on a FIRM, a description of the flood zones, and information on amendments or revisions to the FIRM, visit the section titled "Flood Insurance Rate Maps and Flood Insurance."
Flood Hazard History in
Prince George’s County
Prince George's County has experienced some riverine and stream flooding in recent decades, although sound management of flood hazard areas and construction of flood control projects has reduced potential losses. Notable riverine and coastal flooding has occurred several times since 1933.
- August 1933 – This unnamed hurricane caused flooding along the Potomac River and throughout the Chesapeake Bay; the Livingston Bridge on Piscataway Creek also flooded.
- October 1954 – Hurricane Hazel raised water levels in the Potomac River Basin; statewide, the storm caused 6 deaths and an estimated $11.5 million in damage.
- August 1955 – Hurricane Connie caused riverine flooding that inundated a large commercial section of Upper Marlboro and flooded several buildings along Piscataway Creek; surge reached 4 feet above normal at the confluence of Patuxent River with Western Branch.
- August 1971 – Heavy rain and flooding.
- June 1972 – Tropical Storm Agnes; this storm of record brought high water levels along the Patuxent and Potomac River basins; statewide, it caused 19 deaths and $80 million in damage; in Prince George’s County, the storm caused more than $10 million in damage (see box).
- September 1975 – Hurricane Eloise; heavy rain and flooding; Prince George’s County was included in the major disaster declaration.
- September 1978 – Hurricane David; Prince George’s County was included in the major disaster declaration.
- November 1985 – Hurricane Juan affected the Potomac River Basin; Prince George’s County was included in the major disaster declaration.
- September 1996 – Hurricane Fran; remnants of this large storm caused flooding along the Potomac River Basin; Prince George's County was included in the major disaster declaration.
- September 2003 – Hurricane Isabel produced widespread wind damage, power outage, and localized flooding.
- June 2006 – Heavy rain and flooding.
- May 2008 – Heavy rain.
The Legacy of Tropical Storm
Leaving behind more than $10 million in damage in Prince George’s County and the City of Laurel, Tropical Storm Agnes moved through the area on June 21-22, 1972. Newspaper reports described the aftermath:
- $1 million in damage to public buildings, roads and bridges.
- Worst hit areas included along Chillum Road, Lewisdale, the Green Meadows subdivision in Hyattsville, Lakeland section of College Park, Brentwood, the Adelphi Mill area on Riggs Road, Oxon Run Drive, Tucker Road Bridge, and Water Street Bridge in Upper Marlboro.
- More than 1,800 people were served at shelters.
- Home foundations were braced with sandbags, propane gas tanks became detached, and basements were flooded.
- County personnel evaluated livability of damaged structures.
- WSSC reported erosion damage to some water supply mains; low-lying sewage collection and pump facilities were damaged.
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Flood Insurance Rate Maps and Flood Insurance (NFIP, CRS, CTC, FIRMs, LOMA/LOMR)
National Flood Insurance Program (NFIP) Information
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 20,000 communities across the United States and its territories.
The NFIP is managed by the Federal Emergency Management Agency (FEMA) and theFederal
Insurance Mitigation and Administration (FIMA) Directorate. FIMA manages the insurance component of the NFIP and oversees the floodplain management aspect of the program.
The NFIP, through partnerships with communities, the insurance industry, and the lending industry, helps reduce flood damage and helps to save the nation more than $1.1 billion a year in prevented flood damages. Further, homes constructed in compliance with NFIP building standards suffer less damage from floods than those not built in compliance. A study by the Multi-hazard Mitigation Council indicates that each dollar spent on mitigation saves society an average of four dollars.
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 as flood insurance policies. For more information on NFIP, visit the FEMA website at http://www.fema.gov/about/programs/nfip/index.shtm.
Facts Everyone Should Know About the National Flood Insurance Program
- Everyone lives in a flood zone.
- Flood damage is not covered by homeowners’ insurance policies.
- You can buy flood insurance no matter what your flood risk.
- There is a low-cost policy for homes in low to moderate risk areas.
- Flood insurance is affordable.
- Flood insurance is easy to get.
- Contents coverage is separate, so renters can insure their belongings too.
- Up to a total of $1 million of flood insurance coverage is available for non-residential buildings and contents.
- There is usually a 30-day waiting period before the coverage goes into effect.
- Federal disaster assistance is not the answer.
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.
- 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 (NFIP). Prince George’s County participates in the NFIP.
- It’s a good idea to buy, even in low or moderate risk areas: approximately 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.
- For the Preferred Risk Policy, buildings and content coverage starts at $129 a year.
- You can buy up to $250,000 of coverage for your home and $100,000 of coverage for your contents.
5. Flood insurance is affordable.
- A $100,000 flood insurance premium would cost about $400 a year ($33 a month).
- In comparison, for a $50,000 loan at 4% interest, your monthly payment would be about $240 a month ($2880 a year) for 30 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 non-residential buildings.
9. There is usually a 30-day waiting period before the coverage goes into effect.
10. Federal disaster assistance is not the answer.
- Federal disaster assistance is available only 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.
Source: FEMA: NFIP
PRINCE GEORGE’S COUNTY RESIDENTS RECEIVE A 25% REDUCTION IN FLOOD INSURANCE RATES
Community Rating System (CRS)
The Community Rating System (CRS) is a program started in 1990 under the NFIP. The program was designed to recognize and encourage community floodplain management activities that exceed the minimum NFIP standards. Under the CRS, flood insurance premium rates are adjusted to reflect the reduced flood risk resulting from community activities that meet the three goals of the CRS: (1) reduce flood losses; (2) facilitate accurate insurance rating; and (3) promote awareness of flood insurance.
There are ten CRS classes: class 1 requires the most credit points and gives the largest premium reduction, while class 10 is the entry level into the CRS and carries no premium reduction. Prince George’s County is currently rated Class 5 under the CRS, which translates to a 25% reduction in flood insurance rates for local residents and businesses. The Class 5 rating places Prince George’s County in the top 3% of over 1,200 communities nationwide that participate in the CRS. For more information on the CRS, visit the FEMA web site at http://www.fema.gov/business/nfip/crs.shtm.
The Cooperating Technical Partners
(CTP) Program Activities in the County
Under the CTP Program, the County has conducted and
continues to conduct activities which utilize GIS-based tools. Such
- Completion of countywide GIS-based 2-foot topography using
LIDAR technology. FEMA, the Maryland State Highway Administration, the Maryland-National Capital Park & Planning Commission and the County agreed on cost-sharing;
- Updating FEMA's Flood Insurance Study (FIS) and Flood
Insurance Rate Map (FIRM). This endeavor will result in the
production of the premier digital FIRM for the County. On September 30, 2010, FEMA released the preliminary FIS and DFIRM;
FEMA is proposing to issue a revised preliminary FIS and FIRM
for the County in February 2013.
- Conducting a technical review of FEMA map amendment (LOMA) and
map revision (LOMR) requests.
- Conducting floodplain studies for developers using our
GIS-based H&H models. Fees average approximately $2,500 for this
Is Your Property in a Flood Hazard Area?
Flood Hazard Areas are areas that will be inundated by the flood event having a 1-percent chance of being equaled or exceeded (100-year flood) in any given year. Smaller scale floods (50-year and 10-year) have a greater chance of occurring in any given year and can also pose a significant flood hazard to persons and property in close proximity to channels and streams. Additionally, floods larger than the mapped 100-year event can occur.
First and foremost, you should become informed as to the flood hazard potential on your property. The Prince George’s County Department of Public Works and Transportation will review floodplain information and studies available in their files to determine the location of your property with respect to the floodplain as established in the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps. You may contact the Prince George’s County Department of Public Works and Transportation at (301) 883-5777 for assistance with this information.
Any information provided by the County does not constitute an assurance or representation that flooding may or may not occur on your property during any given event, but should assist you as a general matter in determining the need for flood insurance by assessing the extent of flooding potential on your property.
Flood Insurance Rate Maps (FIRMs)
The FEMA Flood Insurance Rate Map (FIRM) is the official map showing the community’s Special
Flood Hazard Areas . This map is utilized as the basis to assess flood risk based on compliance with the minimum requirements for flood management under the NFIP and to determine if flood insurance is required for structure(s) on a property. Although the map is not property specific (e.g. no lot boundaries), by using the major roads and flooding sources for reference, users can get an idea of the flood risks in their area. The map is available to view online at the Map Service Center ( msc.fema.gov ) or at the Prince George’s County Department of Environmental Resources’ offices in Largo, Maryland. Additionally, the Map Service Center site has an address search feature that allows a user to find the correct FIRM panel using their address in an online search tool.
For additional assistance with using the FIRMs, please contact the FEMA Map Assistance Center at 1-877-FEMA MAP, visit the following website ( www.fema.gov/hazard/map/firm.shtm).
Letters of Map Amendment and Revision (LOMA/LOMR)
In some cases, a lender determines that a property is in the Special Flood Hazard Area (SFHA), or 100-year floodplain, and requires the owner to purchase flood insurance. If the property owner wishes to dispute the fact that they are in the SFHA, they can apply for a Letter of Map Amendment (LOMA) or a Letter of Map Revision Based on Fill (LOMR-F), if fill placement is the basis of the request. Also, a Conditional Letter of Map Revision (CLOMR) or Letter of Map Revision (LOMR) may be required if a land development project would result in changes to the SFHA.
Forms for this application process may be found on FEMA’s website.
You may also access tutorials designed to assist in the preparation of these forms at online-tutorials. This tutorial will guide you through the application and provide tips on filling out the forms.
Upon receiving a completed application, FEMA reviews property-specific information and makes a final flood zone determination for the property. Once an application is received with all the required supporting data, the LOMA or LOMR-F is normally issued within 60 days. If the LOMA or LOMR-F removes the SFHA designation from the property, it can then be presented to the lender as proof that there is no Federal flood insurance requirement for the property. Bear in mind that even though a LOMA or LOMR-F may remove the Federal requirement for flood insurance, a lender retains the prerogative to require flood insurance.
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Elevation certificates are prepared by surveyors and document the ground elevation, floor elevation, and general building characteristics for a structure in relationship to the Base Flood Elevation. Typically, it is the responsibility of the homeowner to obtain an elevation certificate. The County has approximately 763 elevation certificates on file electronically and available to the public. Property owners may use the certificates for flood insurance rating purposes, and the County uses the detailed information to evaluate mitigation options. Elevation certificates are available for the structures listed in the following table. For more information on elevation certificates please call Mike Colgan at (301) 883-5944.
to Elevations Certificate (PDFs)
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Known Floodprone Structures
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Flood Warning Systems
Flood Warning System at Western Branch
The Western Branch Comprehensive Watershed Management Plan was prepared by the Prince George’s County Stormwater Management Technical Group in 1981. Even though the US Army Corps of Engineers had constructed a floodway through Upper Marlboro to carry flood waters away, certain commercial, residential, and other structure types have been found to be subject to flooding in the Upper Marlboro Area. To date, no additional flood control devices have been proposed or planned to mitigate these known flooding hazards. A consulting engineering firm, Engineering Technology Associates (ETA), has completed hydrologic and hydraulic analyses or a watershed study of Western Branch. This study was not designed to produce or evaluate possible solutions that will minimize flooding problems in the Upper Marlboro area. Rather, this study was meant to determine the flood levels in the Western Branch at Upper Marlboro. This study will form the technical basis to be used by the County to select and evaluate possible solutions to the flooding problems in the Watershed. Until the final study and selection of alternatives is completed and ready for implementation, it would be prudent to have an interim program for limiting the extent of flood damage that may occur. Such an interim program to limit flood damage has been proposed in the form of a flood warning system. The Flood Warning System would provide for the monitoring of rainfall and stream flow data to determine if a flood is imminent. The Flood Alerting System will allow the County to use the information gained with the Flood Warning System to alert those in danger that the danger exists.
The U.S. Army Corps of Engineers completed a study of the efficacy and desirability of installing a flood warning system in Western Branch. The study indicated that such a flood warning system would be feasible and desirable. The designed and implemented flood warning and alerting system for the Western Branch is a model for other watersheds within the County. The flood warning and alerting system will continue to provide an additional margin of safety and will be retained as a permanent feature of the Western Branch Flood Management System.
The flood warning system has been integrated into the County’s emergency management system. The flood warning system reports rainfall and stage elevation data during the course of a storm event. When flood waters begin to rise, emergency management has access to this information, which can be used to develop a comprehensive understanding of the status of a flood, in real time.
Prince George’s County received state grant funding to upgrade the Western Branch Flood Warning System. The updated system is in full operation.
Flood Warning System near/at City of
The City of Laurel has two distinct types of flood risk. The more probable risk is riverine flooding and the other risk is associated with dam failure. The City works cooperatively with the County and the Washington Suburban Sanitary Commission (WSSC) to alert citizens to potential flood events. The City communicates with its residents using a variety of media which can be used to convey information about preparing for and responding to a flood event. To learn more about the flood warning system for the City of Laurel, you may visit the City of Laurel Emergency Services webpage at http://www.laurel.md.us/content/emergency-services
Flood Warning System at Anacostia
According to a preliminary Anacostia River Watershed Study prepared by Greenhorne and O'Mara, Inc. in 1993, more than 3,000 structures may be floodprone within the Prince George’s County portion of the Anacostia Watershed. Given the fiscal constraints of flood management in the Anacostia, a flood warning system is a cost effective flood hazard mitigation measure. The County worked with the U.S. Army Corps of Engineers to develop the flood warning system for this watershed. The flood warning system at Anacostia River is in full operation.
Alerts – Major Events and Local Emergencies
Most cell phone carriers offer, and most phones have, text messaging capability. It’s easy to use and relatively inexpensive. For more information on this feature, contact your carrier.
The Prince George's County Office of Homeland Security/Office of Emergency Management (OHS/OEM) offers a service, known as Notify Me Prince George's, which is a secure, reliable communications system that is critical for preparedness, response and recovery. The ability to alert communities quickly and get County personnel in action fast can make a critical difference in public safety. In the event of a major flood or other flood-related hazard, individuals registered in the system can be notified via e-mail accounts, cell phone, pager and wireless PDA. If you would like to be added to our database, register online at Notify Me. You may include more than one contact number or e-mail address.
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Countywide Flood Damage Reduction Strategies
Flood Study Findings
The multi-agency Stormwater Management Technical Group has
completed a fifteen-year study effort to define the extent of
the major flooding problems in the County. The study shows
that approximately 4,000 structures are flood prone in a
100-year storm event. Much of the flooding is concentrated in
the older, highly-urbanized inner beltway communities targeted
Countywide Comprehensive Flood Damage Reduction
With the identification of these major flooding problems, the County is faced with the dilemma of how to protect public safety and welfare and, at the same time, continue to maintain an acceptable level of traditional services at a reasonable cost. The 3,000 residential flooding problems could require more than $100 million dollars and decades to correct. The County’s strategy to address flood conditions include: evaluating flood mitigation alternatives; recommending the most suitable flood mitigation alternatives; performing a preliminary design of the solutions for those major problem areas; seeking Federal and State grants for project construction; and develop a long-term flood reduction program for the County.
A public education program, flood warning systems, and flood proofing and acquisition of the most severely flood prone homes are also potential options for reducing flood damage. Design work will also proceed on the most severely effected flooding areas.
Prince George's County Hazard Mitigation Plan (PDF)
Annual Evaluation Report for the Hazard Mitigation Plan (PDF)
Flood Damage Reduction
As part of a flood damage reduction effort, funding is
appropriated in the Capital Improvement Project (CIP) budget to
conduct planning and design for flood mitigation projects.
Implementation of projects is subject to availability of funding.
Projects are undertaken to solve isolated and sever residential
flooding problems and to solve the most severe flooding problems.
A priority system was developed based on depth and
frequency of flooding and number of floodprone structures
within a geographic area. The 10
highest priority problems to be addressed first are shown
below. These projects account for approximately 50% of the
total number of floodprone structures countywide.
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- Anacostia Levee Improvements. Priority areas 1, 4, and 6
- protects approximately ,300 structures;
- Northeast Branch - East West Highway. Priority area 2 -
protects 191 structures;
- Northeast Branch - Bladensburg. Priority area 3 -
protects 58 structures;
- Oxon Run - Forest Heights. Priority area 5 - protects 43
- Beaverdam - Landover. Priority area 7 - protects 40
- Paint Branch - Cherry Hill Road. Priority area 8 -
protects 18 structures;
- Indian Creek - U. S. Route 1. Priority area 9 - protects
29 structures; and
- Northwest Branch - East West Highway. Priority area 10 -
protects 92 structures.
Property Protection Projects (retrofitting, drainage, protecting against high wind, etc.), and Substantial Improvement/Damage
In some cases, retrofitting existing buildings or regrading a yard can help reduce the potential for flood damage to structures and their contents. Retrofitting techniques include elevating buildings above flood levels, wet or dry floodproofing (commercial structures only), and installing backflow preventers to protect floors and contents from sewer backups. A building permit may be required for retrofitting and structural projects.
There are also temporary measures that can help to protect your property during a flood event. You can plan ahead about where and how you will move furniture out of harm’s way; keep materials like sandbags, plywood, plastic sheeting and lumber handy for emergency waterproofing; and clear brush and debris away from storm drains and ditches so water can drain away from the structure.
The following guides contain more information on protecting your property:
- “Residential Drainage: A Homeowner’s Guide to Drainage Problems and Solutions” available from Prince George’s County. This free guide can be obtained by calling Paul DeSousa at (301) 883-5871 or (301) 883-5832
- “Homeowner’s Guide to Retrofitting: Six Ways to Protect Your House from Flooding” (FEMA Publication #312), includes information on protecting a structure from flooding and information about available financial assistance. This free guide can be obtained by calling 1-800-480-2520 or online.
For additional questions about these types of projects, or for information on permitting, please contact the Prince George’s County Department of Environmental Resources at (301) 883-5776.
Homeowners who are planning substantial improvements to their structure should contact the Permits and Review Division for a residential building permit. Elevating or floodproofing may be required if you plan to substantially improve your existing structure (the cost of the improvement or add-on is up to 50% of the value of the existing structure).
If your property is substantially damaged by a flood (50% of the value of the building), Federal regulations may require you to elevate or floodproof before you can rebuild. The document titled “Answers to Questions about Substantially Damaged Buildings” (FEMA-213, May 1991) will help answer questions on this topic and can be obtained free by calling 1-800-480-2520 or by going online to http://www.fema.gov/library/viewRecord.do?id=1636 .
For additional questions about substantial improvements, or for information on permitting, please contact Paul DeSousa at (301) 883-5871.
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Qualified County staff are available at the Permit and Review Division to discuss your options and to help you plan and build a safe project while complying with the County Floodplain Management Ordinance.
Building permits ensure safe construction inside and outside floodplains. The Prince George’s County permitting process is designed to ensure that all construction in Prince George’s County is safe. A permit is required for all new construction and, most of the time, you must obtain a permit for repairing or replacing existing features. Before you begin construction or add-on to an existing building, find out which permits are required by contacting the Permit and Review Division.
In addition to regular building permits, special regulations apply to construction in floodways and the floodplain. No construction, including filling, is allowed in the mapped floodway without an engineering analysis that shows the project will not increase flood damage elsewhere. Any activity outside the floodplain but within a natural or man-made watercourse also requires a permit.
Homeowners who are planning substantial improvements should contact the Permit and Review Division for a residential building permit. Elevation or
flood proofing may be required if you plan to substantially improve your existing structure (the cost of the improvement or add-on is 50% of the value of the existing structure). If your property is substantially damaged (50 percent of the value of the building), Federal regulations may require you to elevate or
flood proof before you can rebuild.
To report illegal floodplain development or to verify that proper
construction permits have been issued for a project, contact the
Prince George’s County Department of Public Works and Transportation at
(301) 883-5777. An inspector will investigate.
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GIS and Mapping Components
GIS-based Floodplain Submittal
Request in writing that a floodplain study be conducted by the County using GIS-based hydrology and hydraulic models with the property boundary (lot/parcel) highlighted on a tax map which clearly indicates the area of interest. The request should be sent to:
Program Support Section
Sustainability Services Division
Department of Environmental Resources
9400 Peppercorn Place, Suite 610
Largo, Maryland 20774
Once a letter is received, along with the floodplain study fee (see Chapter 2.8.3 of the County’s Stormwater Management Design Manual for Fee Schedules), the request will be logged in and a 2-week turnaround time is anticipated unless there are extenuating circumstances or information is missing which precludes the study from being completed.
A County engineer will review the original request. In some cases, additional information may be required for the study to be completed. The County engineer will notify the applicant of any missing information. The existing or proposed stream crossing information necessary to complete the study is:
- Road profile;
- Minimum road elevations;
- Number of pipes;
- Pipe/culvert dimensions;
- Pipe material and type;
- Upstream and downstream maximum low chord elevations of each pipe;
- Upstream and downstream stream invert elevations of each pipe;
- Length of pipe/culvert;
- Number of piers;
- Pier shape;
- Width of piers;
- Headwall or wingwall type;
- Federal Highway Administration chart number for the culvert; and
- Federal Highway Administration scale number for the culvert.
The information provided must be surveyed and tied into existing County topography. In addition, if there is a proposed stream crossing, the location should be clearly shown in the plan view.
If the study involves a balance of cut and fill, the area of cut as well as fill must be clearly defined.
Once a study is complete, a letter and map will be sent to the applicant with cross-section locations and 100-year floodplain elevations.
If the floodplain elevations are determined based on the County’s GIS topography, a freeboard will be added. However, if the applicant provides more detailed topography, no freeboard will be added.
The floodplain will need to be delineated (by the applicant) on a detailed site plan and submitted to the Department of Public Works and Transportation (DPW&T) for review and approval.
Note: Both FEMA and MDE will accept the County approved GIS-based floodplain.
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Under Prince George’s County Code Subtitle IV, Group 4, the Department of Environmental Resources has the responsibility to conduct watershed studies in order to:
- Determine the magnitude and frequency of potential flood events based on existing conditions;
- Determine the magnitude and frequency of potential flood events based on development that is planned for the future;
- Define the possible alternative management techniques to control floods and minimize flood damage; and
- Identify appropriate stormwater management strategies to alleviate the water quality impacts of land development and stream channel erosion and assist in the attainment and maintenance of water quality standards consistent with Federal, State and County programs and regulations.
The Stormwater Management Technical Group is an interagency technical group consisting of representatives from the Department of Environmental Resources and the Maryland-National Capital Park and Planning Commission, which has been formed to study watersheds in the County. These technical studies include analysis of existing and planned land use, watershed hydrology, stream hydraulics, topographic analysis, evaluation of flood hazard mitigation alternatives, pollutant loading analysis, analysis of various water quality control techniques, and the National Pollutant Discharge Eliminate System (NPDES) Program.
The evaluation of flood hazard mitigation alternatives includes the following:
- Analysis of the runoff characteristics of both existing and planned development conditions in order to assess the impact of future land development and to aid in the development and evaluation of alternative land use patterns;
- Flood insurance;
- Flood proofing;
- Elevation of structure;
- Zoning and local land use regulations;
- Flood warning systems;
- Acquisition of flood prone structures;
- Stormwater management;
- Bridge and culvert improvement;
- Channelization or channel modification;
- Retention/detention structures;
- Stream relocation;
- Stream enclosure; and
- Combinations of the above.
The above alternatives are evaluated based on the following criteria:
- Level of protection of mitigation provided;
- Physical, legal and financial constraints;
- Environmental impacts, including disturbance of wetlands, benefits to water quality, affect on aesthetics;
- Public health and safety; and
- State and Federal permit requirements.
A number of watershed studies have been completed and adopted by the County Council. These watershed studies are:
- Tinkers Creek (adopted in September, 1980);
- Western Branch (adopted in July, 1983);
- Piscataway Creek (adopted in July, 1986); and
- Henson Creek (adopted in July, 1986).
Other watershed studies which have been completed are:
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- Folly Branch;
- Bald Hill Branch;
- Southwest Branch;
- Collington Branch;
- Charles Branch;
- Oxon Run;
- Anacostia River; and
- Beaverdam Creek
The County Office of Highway Maintenance is responsible for a wide range of activities, part of which is pipe repair and replacement; ditch and channel maintenance; inlet and drainage pipe cleaning; stormwater management facility maintenance; and maintenance of various flood control facilities.
The following activities are specifically related to maintaining storm drainage and free flowing streams:
- Floodplain maintenance (cutting, mowing and weeding of various sites);
- Cleaning of streams and other stormwater maintenance sites (removal of debris, sediment and materials foreign to the natural vegetation);
- Application of herbicides along improved channels and within pumping stations to aid in vegetation management; and
- Cleaning County-owned and maintained earthen and concrete channels to remove obstructions, cut out heavy woody growth, and perform repairs.
Another important aspect of drainage maintenance is the inspection program. Each year more than 2,400 service requests are received from County residents. Inspectors respond within three working days, unless an emergency is reported, in which case the response is immediate. After high water events, especially if water overtops a road or bridge, an inspection is performed to determine if maintenance and repairs are warranted. A 24-hour emergency on-call program covers emergency service requests, and flood control and pumping station responses.
For questions regarding drainage maintenance, or to report a drainage problem, please contact the Office of Highway Maintenance Customer Service Office at (301) 499-8520. Further information can be found online at Storm Drainage.
Flood Control Facility Maintenance
In the 1940s, the U.S. Army Corps of Engineers constructed the Anacostia Flood Control Project. To manage drainage on the land-side of the levees, the Corps installed four pumping stations. The County operates and maintains the pumping stations, and in coordination with the Corps, conducts an annual inspection of the levees, floodway channel and pumping stations. The County is responsible for maintenance, including mowing, vegetation control, debris removal, and stabilization of erosion.
In addition to maintaining the Anacostia flood control project, the County owns, manages, and maintains several non-Federal flood control projects:
- Sligo Creek flood control levee, built by the Washington Suburban Sanitary Commission in 1973;.
- Northeast Branch flood and erosion control channelization (above East-West Highway), built by the Washington Suburban Sanitary Commission in 1976;
- Henson Creek flood control levee and channelization near Morningside, built by the Washington Suburban Sanitary Commission in 1972;
- Oxon Run flood control levee near Green Valley Drive, built by the Washington Suburban Sanitary Commission in 1982;
- Oxon Run tributary floodwall, built by the County to protect homes and a school (completed 2004); and the
- Northeast Branch flood control levee near Allison Street, built by the Washington Suburban Sanitary Commission.
One of the responsibilities of the Sustainability Services Division (SSD) is to respond to citizen complaints regarding drainage problems. Drainage complaints range in nature from property flooding to home flooding and include such concerns as erosion and problems associated with sump pump discharges. Groundwater-associated problems are investigated with remedial actions suggested for homeowners, along with the provision of a residential drainage manual.
SSD investigates an average of 500 complaints per year, some of which evolve into corrective projects. Approximately 45 new drainage projects are initiated each year as a result of either homeowner complaints, referrals by other agencies, or requests by County Council Members.
If you are experiencing drainage problems, please call the (301) 883-5832 for assistance.
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As part of its overall floodplain management program, the County provides a number of services to local residents and businesses. These services include the following:
- Public assistance with inquiries about Federal Emergency Management Agency (FEMA) flood zones and floodplains generally;
- Proclamation from the County Executive and Council declaring June to be “Flood Awareness Month” with tips on flood safety and where to get additional information; airing of a local flood management video on County Cable; displays in public libraries on flood awareness, flood safety and related information;
- Flood Protection Library – Local libraries have information on flood mitigation and insurance (materials include local flood studies and contact information, as well as “generic” flood information materials from FEMA);
- The County publicizes the availability of floodplain information with lenders, realtors, insurance agents and the general public needing flood zone determinations for mortgage lending and insurance rating. In addition, information on floodplains generally, floodplain regulations, flood safety tips, natural and beneficial significance of floodplains and similar information is disseminated through a variety of outlets including: County fair display, various public outreach events held throughout the year, library displays and holdings, press coverage in the local paper, county cable television, and Department of Environmental Resources (DER) press release;
- Flood Warning Program – The County has a comprehensive Flood Warning Program for Western Branch and the Anacostia River, which includes a state-of-the-art stream gauge network and flood warning system;
- Flood Protection Assistance – The County offers technical assistance to residents with drainage and flooding problems. In addition, a number of capital projects are undertaken to mitigate for potential flood events. Capital projects include acquisition of floodprone structures, floodproofing, and construction of drainage improvement projects;
- Development Review Activities – The Department of Public Works and Transportation (DPW&T), Office of Engineering reviews development proposals to ensure compliance with relevant floodplain, stormwater management, and grading ordinances to protect the health, safety, and welfare of local residents and businesses; and
- Maintenance of Stormwater Management Facilities – DPW&T, Office of Highway Maintenance, Storm Drain Maintenance Division (SDMD), supports the Department's goal and mission of professional service, and public safety. The SDMD is charged with the inspection, maintenance and emergency response of the County’s public infrastructure including storm drain systems, Storm Water Management Facilities (SWMF), and flood control facilities. Currently, there are approximately 460 SWMF maintained by the County. Generally, the SDMD provides functional maintenance* of the SWMF’s ensuring operational function and compliance with the State and County regulations for Stormwater Management practices and standards.
- Community Partnering – DPW&T supports and partners with local communities desiring to enhance routine SWMF pond maintenance activities. Under such agreements, the County remains responsible for the overall function of the pond, as described above. Those communities interested in participating enter into a signed Maintenance Agreement with the County assuming specific maintenance activities with the pond.
For more information about flood management, flood safety tips and flood insurance, contact Yanping Zhang at (301) 883-5787. For information on the National Flood Insurance Program, contact the Federal Emergency Management Agency (FEMA) at (800) 427-4661.
* Functional Maintenance may be defined as permanent maintenance of the facility to include semi-annual mowing and physical maintenance of the storm drain system, pond riser structure, outfalls, and embankments. Crews will also remove litter and trash during the semi-annual mowing operations to the extent possible. SDMD crews also respond to emergency service requests as necessary to ensure operational integrity of the ponds.
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Hurricane Season Special Warnings
Hurricane Season and Flood Awareness
The warm weather of summer brings with it the start of another change in weather commonly known as “hurricane season”. During this six-month period from June through November, the likelihood for hurricanes and tropical storms that impact the eastern United States is extremely high. While hurricane events in Prince George’s County are quite rare, the possibility of associated tropical storms, intense thunderstorms, and flood events are very real.
Residents and business owners located near a stream may wish to take measures to safeguard against potential losses associated with flooding. The Prince George’s County Department of Environmental Resources (DER) has a number of services available to assist local home and business owners with information about how to reduce the likelihood of flood losses. DER administers a comprehensive floodplain management program that includes: technical assistance to property owners with flooding and drainage problems, construction of capital projects to alleviate drainage and flooding problems (drainage systems, floodwalls, stormwater management ponds, levees), administration of a floodplain/stormwater management ordinance to prevent building in the floodplain and reduce the effects of development on “downstream” properties, dissemination of floodplain information to residents, businesses, lenders and insurance companies, and participation in the National Flood Insurance Program/Community Rating System which enables County residents to purchase flood insurance at a reduced rate.
A review of the floodplain studies prepared by FEMA and DER can
determine if your property is located in or near the floodplain.
Perhaps the single most important measure that owners of flood prone
property can make is to purchase flood insurance. To obtain
additional information on the location of your property as it
relates to the floodplain, call the
Department of Public Works and Transportation at (301) 883-5777. For more
information on how to obtain flood insurance call the
National Flood Insurance Program at (800) 427-4661.
Information on flood insurance, flood safety tips, flood and
disaster preparedness can also be found on the FEMA website
at www.fema.gov and at the Maryland Department of the
Environment (MDE) website.
Although flooding and other natural disasters can strike at
any time, advance planning and preparedness will go a long
way in reducing the impacts of a natural disaster.
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Disaster Do’s and Don’ts
Things you can do now to prepare for a flood event
- Educate yourself of the flood risks in your area;
- Find a fast and safe route to high ground from your home, place of work and school. Be aware of which transportation routes may be closed in case of flooding;
- Put together an emergency flood kit which should includes: a first aid kit with essential medicines, drinking water, a flashlight, batteries, non-perishable food, a portable radio, a can opener, blankets and warm clothing;
- Be sure to have temporary care lined up for your pets in case of flooding;
- Buy flood insurance; most homeowners' policies do not cover flood damage;
- Store your valuables and toxic materials in higher areas of your house; and
- Create a list of the contents in your house complete with photographs. This will be useful for flood insurance claims and tax deductions following a flood event.
If time permits
- If there is sufficient time, protect your home with sandbags, plastic sheeting, and plywood. Remember sandbags should not be stacked against the building;
- Turn off all utilities; and
- Stock bathtubs and sinks with fresh water.
Things to do during a flood event
- Pay attention to the local weather forecast and flood warnings;
- Avoid flooded areas; DO NOT ATTEMPT TO WALK, SWIM OR DRIVE THROUGH A FLOODED AREA;
- If trapped in your home, move to the upper stories of the house and the roof if necessary. WAIT FOR HELP TO COME TO YOU;
- Stay away from electrical equipment in wet areas; and
- If your car is stuck in a flooded area, abandon your car as fast as possible to seek higher ground.
Things to do following a flood
- Do not use food, water and medicine contaminated by the flood waters;
- Do not use tap water until the community officials advise that it is safe;
- Be aware of hazards caused by structural damage to buildings;
- Turn off all utilities if you have not already done so. Do not use open flames when searching your home after a flood because of possible gas leaks;
- Electrical outlets and wiring need to be checked by a professional before usage. The No. 2 flood killer after drowning is electrocution;
- Dispose of contaminated carpeting and drywall;
- Be careful about drying wooden items in the sun because warping may occur;
- Do not pump out flood water from basements all at once. Pump out about one-third of the water per day;
- Document all flood loss for flood insurance, government assistance, and tax deduction purposes; and
- Pay attention to local news for information on any financial assistance available from FEMA. If access to the internet is available, use FEMA’s website for up-to-date information on disaster assistance ( www.fema.gov ).
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Frequently Asked Questions (FAQs)
- My mortgage company informed me that I am in a designated Special Flood Hazard Area (SFHA). What is a SFHA?
The SFHA is what is commonly referred to as the "100-year" floodplain. This is somewhat of a misnomer because it often leads people to believe that this is a flood that occurs only once in 100 years when in fact there might be two "100-year" floods within a month. The "100-year flood" is the name given to a flood that has a 1% chance of occurring in any given year. In fact, over a 30-year mortgage, there is a 26% chance that a flood will occur to a home and only a 4% chance of a fire.
- Why is my lender requiring the purchase of flood insurance?
For nearly every mortgage transaction in the United States that involves a structure, the lender reviews current National Flood Insurance Program (NFIP) maps for the community in which the property is located. The NFIP map review is made to determine the location of the property in relation to the SFHA. If the lender determines that the structure is indeed located within the SFHA and the community is participating in the NFIP, the borrower is notified that flood insurance will be required as a condition of receiving a loan. These lender requirements are set forth in the Flood Disaster Protection Act of 1973 and the National Flood Insurance Reform Act of 1994. Stipulations of these legislative acts require the purchase of flood insurance by property owners who are being assisted by Federal programs or by federally regulated institutions in the acquisition or improvement of land, or facilities, or structures located or to be located within an SFHA.
- How can a property owner determine if the property is in a Special Flood Hazard Area (SFHA)?
FEMA publishes Flood Insurance Rate Maps, which show the flood hazard areas in communities. The Flood Insurance Rate Map for the County is on file with the Department of Environmental Resources (DER) and many insurance companies. In addition to the Flood Insurance Rate Map, DER has done a number of watershed studies covering most of Prince George's County. The Flood Insurance Rate Map and local floodplain maps can be viewed by the public at the DER offices in Largo. In addition, local residents and business owners can call the Department of Public Works and Transportation at (301) 883-5777 to request floodplain information about their particular property.
- What if I disagree with my lender's determination that I am in the flood zone?
Property owners may not contest the requirement if the lending institution has established the requirement as part of its own standard lending practices. However, if a lending institution is requiring the insurance to meet mandatory flood insurance purchase requirements of the NFIP, the property owner and lender may jointly request that FEMA review the lending institution's determination. The FEMA review merely looks to see if the determination is accurate based upon a review of the NFIP maps and the location of the property in relation to the SFHA. If a property owner is not satisfied with the results of this review, they may apply for a Letter of Map Amendment (LOMA), which is a more detailed look at the elevation of the structure on the property and the elevation of the floodplain as shown on the NFIP map. Please call Yanping Zhang at (301) 883-5787 for additional information on the LOMA process.
- Who can purchase a flood insurance policy?
NFIP coverage is available to all owners of insurable property (a building and/or its contents) in a community participating in the NFIP. Owners and renters may insure their personal property against flood loss with "contents coverage".
For the answers to additional questions on flood insurance purchase requirements and flood zone determinations, visit the FEMA website at http://www.fema.gov/business/nfip/
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