Terminology Table of Contents Acknowledgements Reducing Damage from Localized Flooding: A Guide for Communities i ii Reducing Damage from Localized Flooding A Guide for Communities FEMA 511 / June 2005 Table of Contents Acknowledgements ...................................................................................v Terminology ...........................................................................................vii Part I. Introduction Chapter 1. Background ..........................................................................1-1 The NFIP’s Interest ......................................................1-2 About This Guide ........................................................1-3 How to Use the Guide ................................................1-4 Chapter 2. Localized Flooding ..............................................................2-1 The Problem ................................................................2-1 What Can Be Done ......................................................2-5 Where to Get Help ......................................................2-9 Part II. Community-Level Tools and Techniques Chapter 3. Community-Level Activities .................................................3-1 The Strategy ................................................................3-1 A Community Plan ......................................................3-2 Building Capabilities ...................................................3-5 Where to Get Help ......................................................3-8 Chapter 4. Regulatory Tools ...................................................................4-1 A Regulatory Floodplain Map ......................................4-1 Land Use Regulations ..................................................4-7 Standards for Subdivisions ........................................4-10 Floodplain Regulations ..............................................4-14 Site Drainage ............................................................4-17 Where to Get Help ....................................................4-20 Chapter 5. Public Information and Awareness .......................................5-1 Answer Questions .......................................................5-1 Provide Resources for the Public .................................5-3 Deliver Flood Information ...........................................5-4 Educate to Build Community Capability ......................5-6 Where to Get Help ......................................................5-8 Chapter 6. Warning and Emergency Services .........................................6-1 Recognizing the Threat ................................................6-1 Issuing the Warning ....................................................6-3 Responding to the Threat ............................................6-4 Informing the Public ...................................................6-6 StormReady Program ..................................................6-7 After the Flood ............................................................6-8 Where to Get Help ....................................................6-11 Part III. Neighborhood-Level Tools and Techniques Chapter 7. Area Analysis .........................................................................7-1 The “Area” ..................................................................7-1 Conducting the Analysis ..............................................7-2 Follow-Up Activities ....................................................7-8 Funding .......................................................................7-9 Where to Get Help ....................................................7-12 Chapter 8. Drainage Improvements .......................................................8-1 The Drainage System ...................................................8-1 Modifying the Drainage System ..................................8-6 Maintaining the Drainage System ..............................8-13 Where to Get Help ....................................................8-16 Chapter 9. Redevelopment .....................................................................9-1 Redevelopment Objectives ..........................................9-1 Clearing the Area .........................................................9-7 Reuse of the Area .......................................................9-11 Where to Get Help ....................................................9-16 Part IV. Site-Speci.c Tools and Techniques Chapter 10. Retro.tting .......................................................................10-1 Introduction ..............................................................10-1 Retro.tting Techniques ..............................................10-1 Precautions and Parameters .....................................10-13 Community Support ...............................................10-19 Where to Get Help ..................................................10-21 Chapter 11. Flood Insurance ................................................................11-1 NFIP Flood Insurance ................................................11-1 The Community’s Role ..............................................11-6 Where to Get Help ..................................................11-10 References .................................................................................................................R-1 Appendix A. Sources of Assistance ............................................................................A-1 Organizations .......................................................................................A-3 State and Local Entities .........................................................................A-4 Appendix B. Reference Works and Recommended Reading ......................................B-1 Community-Level Approaches ...............................................................B-1 Regulatory Tools ....................................................................................B-2 Public Information and Awareness ........................................................B-3 Warnings and Emergency Services ........................................................B-3 Area Analysis ........................................................................................B-4 Drainage Improvements ........................................................................B-4 Redevelopment ......................................................................................B-4 Retro.tting ............................................................................................B-5 Index Acknowledgements This guide was produced with the assistance and expert advice of numerous specialists throughout the United States. Thanks are extended to the technical reviewers, and to the local, State, and Federal of.cials who provided valuable input through interviews with project staff. Mike Buchert, City of Tulsa, Oklahoma, Public Works Dave Canaan, Director of Charlotte/Mecklenburg County, North Carolina, Stormwater Services Dr. Mow-Soung Cheng, Department of Environmental Resources, Prince George’s County, Maryland Jack DeCicco, State Farm Insurance Company Ted DeBaene, Owen and White, Inc., Baton Rouge, Louisiana Trudi Johnson, CRS Coordinator, Hilton Head Island, South Carolina Ward Miller, Lake County, Illinois, Stormwater Management Commission Doug Plasencia, AMEC Earth & Environmental, Inc., Phoenix, Arizona Andy Reese, AMEC Earth & Environmental, Inc., Nashville, Tennessee Joe Tram, Maricopa County Flood Control District, Arizona Kevin Stewart, Urban Drainage and Flood Control District, Denver, Colorado Tom Donaldson, National Weather Service, Silver Spring, Maryland Daisy Sweeny, Regional Repetitive Loss Coordinator, FEMA Region I Pat Griggs, Regional Repetitive Loss Coordinator, FEMA Region II Dave Thomas, Regional Repetitive Loss Coordinator, FEMA Region III Bob Durrin, Regional Repetitive Loss Coordinator, FEMA Region IV Anna Pudlo, Regional Repetitive Loss Coordinator, FEMA Region V Greg Solovey, Regional Repetitive Loss Coordinator, FEMA Region VI Georgia Wright, Regional Repetitive Loss Coordinator, FEMA Region VII Bonnie Heddin, Regional Repetitive Loss Coordinator, FEMA Region VIII Gregor Blackburn, Regional Repetitive Loss Coordinator, FEMA Region IX Denise Atkinson, Regional Repetitive Loss Coordinator, FEMA Region X Dave Carlton, Civil Engineer, FEMA Region X Clifford E. Oliver, Branch Chief, Risk Assessment, FEMA HQ Michael Grimm, Community Assistance Section Chief, Risk Assessment, FEMA HQ Cynthia Pollnow, Project Manager, Risk Assessment, FEMA HQ Errol Garren, Project Monitor, Risk Assessment, FEMA HQ Mike Robinson, Risk Assessment, FEMA HQ Bill Lesser, Risk Assessment, FEMA HQ Don Beaton, Risk Insurance, FEMA HQ Mary Chang, Risk Insurance, FEMA HQ Sheila Donohoe, Risk Reduction, FEMA HQ Kathleen Wissman, Risk Reduction, FEMA HQ This guide was prepared by URS Corporation, French & Associates, Ltd., and JLM Associates, Inc. under Task Order 269 of the FEMA Hazard Mitigation Technical Assistance Program. Terminology Throughout this guide, the following terms are used. A Zone is de.ned as the Special Flood Hazard Area shown on a community’s Flood Insurance Rate Map. The A Zone is the area subject to inundation during a 100-year .ood, which is the .ood elevation that has a 1-percent chance of being equaled or exceeded each year. There are several categories of A Zones, including AO (shallow sheet .ow or ponding; average .ood depths are shown); AH Zones (shallow .ooding; base .ood elevations are shown); numbered A and AE Zones (base .ood elevations are shown); and unnumbered A Zones (no base .ood elevations are provided because detailed hydraulic analyses were not performed). B Zone is de.ned as an area of moderate .ood hazard, usually depicted on Flood Insurance Rate Maps as between the limits of the base .ood and 500-year .ood of the primary source of .ooding. B Zones may have local, shallow .ooding problems. B Zones are also used to designate areas protected by levees and base .oodplains of little hazard, such as those with average .ood depths of less than 1 foot. BFE is the base .ood elevation. The base .ood is the .ood having a 1-percent chance of being equaled or exceeded in any given year. (It is also known as the 100-year .ood.) The BFE has been adopted by the National Flood Insurance Program as the basis for mapping, insurance rating, and regulating new construction. C Zone is de.ned as an area of minimal .ood hazard, usually depicted on the Flood Insurance Rate Map as above the 500-year .ood level of the primary source of .ooding. C Zones tend to have local, shallow .ooding problems. B and C Zones may have .ooding that does not meet the criteria to be mapped as a Special Flood Hazard Area, especially ponding, localized drainage problems, and streams that drain smaller watersheds. CRS is the abbreviation for Community Rating System, a voluntary program for National Flood Insurance Program-participating communities. The goals of the CRS are to reduce .ood losses, facilitate accurate insurance rating, and promote the awareness of .ood insurance. The CRS was developed to provide incentives for communities to go beyond the minimum .oodplain management requirements to develop extra measures to protect them from .ooding. The incentives are in the form of premium discounts. Community means any city, village, town, county, or other local government with authority to enact .oodplain management measures. DFE is the acronym for design .ood elevation, the speci.ed level to which a structure will be protected from .oods when it is built or retro.tted. FEMA is the Federal Emergency Management Agency, the Emergency Preparedness and Response Directorate within the U.S. Department of Homeland Security. FIRM is the acronym for the Flood Insurance Rate Map, an of.cial map approved by the Federal Emergency Management Agency and adopted by the community that delineates the Special Flood Hazard Area subject to the community’s .oodplain management regulations and the insurance risk premium zones. Floodplain is used in a general sense to mean the area most prone to .ooding, mapped or not. The .oodplain for a localized .ood problem may not be mapped as Special Flood Hazard Area on the Flood Insurance Rate Map. Floodway means the stream channel and that portion of the adjacent .oodplain that must remain open to permit passage of the base .ood. The .oodway is delineated on the Flood Insurance Rate Map or an accompanying Floodway Map and is subject to special development restrictions. Localized .ooding refers to smaller scale .ooding that can occur anywhere in a community. This can include .ooding in B, C, and X Zones as depicted on the Flood Insurance Rate Map. The term is also used to refer to shallow .ooding that occurs in low-lying areas after a heavy rain, .ooding in small watersheds, ponding, and localized stormwater and drainage problems anywhere in the community. In this guide, “local .ooding” and “localized .ooding” are used interchangeably. NFIP is the National Flood Insurance Program. Repetitive loss refers to an NFIP-insured property where two or more claim payments of more than $1,000 have been paid within a 10-year period since 1978. About 20 to 25 percent of repetitive loss properties are rated as being in B, C, or X Zones. SFHA is the Special Flood Hazard Area, or the A and V Zones as depicted on the Flood Insurance Rate Map. B, C, and X Zones are outside of the SFHA. Watershed means an area of any size that drains into a lake, stream, or other body of water; also known as “basin” or “catchment area.” X Zone relates to newer Flood Insurance Rate Maps, which show B and C Zones (see above) as X Zone. The shaded X Zone corresponds to a B Zone and the unshaded X Zone corresponds to a C Zone. Cover photograph courtesy City of Carencro, Louisiana. Reducing Damage from Localized Flooding: A Guide for Communities Part I Introduction This guide is intended to help local offices in cities, towns, villages, and counties in the United States understand what they can do to reduce the damage, disruption, and public and private costs that result from the shallow, localized flooding that occurs within their jurisdictions. This is flooding that all too often escapes the attention received by larger floods or those that are clearly mapped and subject to floodplain development regulations. Part I of the document introduces the content and goals of the guide. It includes Chapters 1 and 2, which: Outline the purpose of the guide and how to use it; Explain what is meant by local or localized flooding; Lay out the scope of the localized flooding problem as it affects jurisdictions throughout the United States; Give reasons why communities would want to deal with these types of flood problems; and Explore how a community can get started to find and implement remedies for its localized flooding problems. Part I: Chapter 1. Background Chapter 2. Localized Flooding Reducing Damage from Localized Flooding: A Guide for Communities Background Most cities, towns, villages, and counties in the United States have one or several clearly recognizable flood-prone areas, usually along a river or stream or other large body of water. These areas usually are identified as the Special Flood Hazard Area (SFHA) on the community’s Flood Insurance Rate Map (FIRM), which is provided to the community by the Federal Emergency Management Agency (FEMA) when it joins the National Flood Insurance Program (NFIP). These flood-prone areas are properly the subject of community, State, and Federal initiatives to minimize the flooding and its impacts. The NFIP and communities address these flood-prone areas through maps, floodplain management criteria, ordinances, and community assistance programs. However, thousands of communities also have shallow, localized flooding problems outside of the SFHA resulting from ponding, poor drainage, inadequate storm sewers, clogged culverts or catch basins, sheet flow, obstructed drainageways, sewer backup, or overbank flooding from small streams. These kinds of flood events can occur anywhere in a community. If these localized floods occurred infrequently, the problems would be minor. However, in some areas localized flooding can be chronic, so that over the years the cumulative damage and recurring disruption from localized flooding can be more than that caused by flooding on major rivers and streams. The costs of insuring buildings that are subject to this repeated damage add up as well. Local and State officials confirm that localized flooding is a problem. They characterize it as “a drainage issue,” “low-level nuisance flooding,” and “headwater flooding.” According to one local official, citizens seem to present more complaints about Chapter 1. Background PART I Reducing Damage from Localized Flooding: A Guide for Communities 1-2 repetitive localized flooding than about deeper, more destructive flooding from larger bodies of water. A community’s floodplain management requirements in the SFHA will protect new construction from localized flooding. However, most communities do not have such regulations for development outside the SFHA, in areas mapped as B Zones, C Zones, or X Zones. If action is not taken, local flooding problems will likely increase over time as development in watersheds and in B, C, and X Zones continues without sufficient land use and building regulations. The NFIP’s Interest Flood insurance is available for all eligible buildings within a community that participates in the NFIP. However, the NFIP currently has no floodplain management criteria for B, C, and X Zones—those areas that lie outside of the SFHA—and no requirements for communities to take action to reduce or prevent losses in these areas. The result is significant financial losses for the NFIP, including the cost of insuring Photo by Michael Democker © 2003 The Times-Picayune Publishing Co., all rights reserved. Used with permission of the Times-Picayune, New Orleans, LA. Flood water does not have to be deep to make a costly mess. Chapter 1. Background PART I repetitive loss properties. Here are some statistics that show the cost of localized flooding to the NFIP: Since 1978 the NFIP has paid over $2.8 billion in claims in B, C, and X Zones. Of that, $1.1 billion was paid for claims on repetitive loss properties. Between 20 percent and 25 percent of all repetitive loss properties are rated as being in B, C, and X Zones. In some communities, over half of the repetitive loss buildings are in B, C, and X Zones. About This Guide Many State and local officials assert that their communities have put forth substantial effort to address localized flooding problems with much success. They say that, although flood mitigation is not always seen as a good use of funds in lower risk areas, communities would benefit from guidance on addressing localized flooding problems. They believe that information for both the property owner and local officials is important, and that both audiences need to understand the necessity for taking action and how reducing flood losses can benefit them and their communities in the long term. This guide is a response to that expressed need. It is meant to help State and local officials understand what they can do to reduce the damage, disruption, and public and private costs that result from localized flooding that occurs within their jurisdictions. Accordingly, this document Supports the premise that State officials, local officials, and residents can do something about localized flooding problems; Focuses on building a community’s capability to minimize its existing localized flood problems and avoid future ones; and Contains ideas and techniques that can work within the existing community framework. Nothing has to be reinvented unless the community wants to do so. This is not a technical manual; there are many excellent technical reference sources already available. Instead, this guide outlines the types of actions that can be taken, explains why they are important and what their potential benefits are, and points the reader in the direction of where to obtain more information and assistance. What is Localized Flooding? In this guide, localized flooding refers to flooding outside the scope of criteria that apply to the SFHA as depicted on a community’s FIRM. This includes areas within and outside the B, C, and X Zones. Such floods are often referred to as: stormwater flooding nuisance flooding flooding on small streams carpet wetters poor drainage ponding How to Use the Guide This guide is organized into four parts. The rest of Part I (Chapter 2) describes the problems that accompany localized flooding, gives reasons why communities would want to deal with these types of flood problems, and lists general actions that can be taken by the community. The three parts that follow describe tools and techniques that can be used for different types of flood problems. The tools should be selected carefully; certain ideas work well in some situations but not in others. Many of the techniques are best applied on a small scale, perhaps building-by-building. Part II addresses techniques for coping with flooding that are appropriate for community-wide action, such as comprehensive planning, regulations, public education efforts, and warning systems. Part III concentrates on the specific neighborhood or block where the flooding takes place. Techniques that are appropriate at this scale are described, including conducting an area-wide analysis, making improvements to the drainage system, or redeveloping flood-prone properties. Part IV narrows the focus even further, offering techniques that can be used building- by-building and by individual property owners to reduce potential flood damage or how to better cope with it when it does occur. These chapters cover retrofitting and flood insurance. A set of appendices lists sources of technical assistance and advice, along with contact information and additional recommended reading. Reducing Damage from Localized Flooding: A Guide for Communities Localized Flooding Localized flood problems sometimes do not get the remedial attention they need, partly because they are not the subject of dramatic headlines or stories on the nightly news, and partly because they fall outside the scope of many local flood protection ordinances, which are geared toward the Special Flood Hazard Area (SFHA) depicted on the community’s Flood Insurance Rate Map (FIRM). However, as local officials, technical staff, and residents of those areas know, this flooding is a significant—and usually recurring—problem. The Problem Localized flooding can result from even minor storms. Runoff overloads the drainageways and flows into the streets and low-lying areas. Sewers back up; yards are inundated. Homes and businesses are flooded, especially basements and the lower part of first floors. Localized flooding poses most of the same problems caused by larger floods, but because it typically has an impact on fewer people and affects small areas, it tends to bring less State or Federal involvement such as funding, technical help, or disaster assistance. As a result, the community and the affected residents or business owners are left to cope with the problems on their own. Finally, flooding of this type tends to recur; small impacts accumulated over time can become major problems. Safety Hazards People are at risk even in shallow flooding. It is not unusual for children, especially, to drown after slipping in shallow water or to be swept into a ditch or storm drain. Even adults can be knocked down by just a few inches of moving water. According to the National Weather Service, almost half of all flood fatalities occur in vehicles. Local storms can quickly fill underpasses and cover bridges, and even two feet of water can float most vehicles, including large ones. If the water is moving, Chapter 2. Localized Flooding PART I Reducing Damage from Localized Flooding: A Guide for Communities vehicles can be swept away. Driving at night during a local flood can be especially hazardous. Emergency workers and other public employees who help in flood response and cleanup risk injury and even death themselves. Water and electricity can lead to a dangerous situation, no matter how shallow the water. Damp electrical system components pose a shock hazard, as do the extra tools and appliances people use to clean up moist conditions. Health Concerns In addition to the obvious risks of drowning and electrocution, there are many less well-known health problems that can be consequences of shallow flooding, particularly if it is recurrent. Damp conditions can trigger the growth of mold and mildew in flooded buildings, especially if the weather is warm and atmospheric humidity high. Molds contribute to allergies, asthma, and respiratory infections, especially in children, the elderly, and those with weakened immune systems. Snakes and rodents are forced out of their natural habitat by flood waters and move into closer contact with people. Gasoline, pesticides, fuel oil, chemicals, and other substances can be brought into the area and into buildings by flood waters. They soak into the soil, building components, and furniture, and can result in long-term health problems. Village of Gurnee, Illinois Children, as well as adults, often do not realize the danger of even shallow flood waters. Chapter 2. Localized Flooding PART I Standing water and wet conditions are breeding grounds for mosquitoes, which are not only a nuisance but also can transmit encephalitis and West Nile Virus. Any flood experience is a strain on individuals and families. Over time, this stress can lead to anger, conflicts with others, inability to sleep, anxiety, hyperactivity, depression, withdrawal, or lethargy. The stress is intensified if there is a sense that the flood water will be back because the problem has not been solved. This can worsen pre-existing medical conditions and contribute to mental health problems. Property Damage Even a few inches of water in the basement or ground floor of a building can cause expensive damage. Carpeting, wallboard, insulation, mattresses, and upholstered furniture must be thrown out and replaced. Flooring, studs, and other wooden parts of the building must be thoroughly cleaned and dried. Business records, photographs, and other papers are often destroyed. Many owners find it cheaper to replace flooded furniture, cabinets, contents, machinery, equipment, and inventory than to try to salvage them. Since these areas often flood frequently, the cumulative damage can be significant. Many property owners outside the SFHA do not have flood insurance. Property and contents damage from flooding is not covered under standard homeowners insurance policies. No amount of money can compensate for ruined keepsakes, photographs, or family heirlooms. Even under non-flood conditions, there can be some structural damage if the soils have been saturated for a long period or repeatedly over time. Foundations can be gradually undermined, wood can rot, and masonry materials can become weakened. Disruption Flood waters can block streets, disrupt traffic patterns, and hinder access to homes and businesses. This can affect the entire community, not just those whose property is flooded. People have to evacuate wet and/or damaged homes, and businesses have to close. Cleanup and repairs take time away from normal routines, interrupting lives and business operations. These difficulties may be serious enough to close a business permanently. All these interruptions, even if short-lived, have ripple effects Even Minimal Risk Zones Can Be Dangerous In 1997, a series of intense thunderstorms in Fort Collins, Colorado, resulted in flooding throughout the city. The Johnson Mobile Home Park, located in an X Zone, was completely destroyed, and five of its residents died in the flood. Indiana Department of Natural Resources Even shallow flooding results in a major cleanup and repair effort. A common approach to cleaning flooded wallboard is to cut and remove the lower 4 feet and replace those sections and the insulation. throughout a community, its citizens, its commerce, and its economy. Costs to Local Government Localized flooding can cause damage to public property, particularly if the flooding recurs periodically. Even though they are intended to withstand some abuse, sidewalks, streets and roads, benches, trash cans, fences, public buildings, signs, and other public property suffer additional wear and tear from flooding and will require repair, replacement, or repainting more frequently than normal. Another cost of flooding is the diversion of local government staff and resources. Flood fighting, repairs to public buildings, extra trash collections, and cleanup of public property are all expenses that are borne by the public. Impacts on the Community In many instances, residents of the flooded areas complain to their local officials, wanting to know why the flooding happens and what is going to be done about it. Such dissatisfaction can even culminate in lawsuits against the local government for damage resulting from, for example, an undersized storm drainage system. Areas that are flooded repeatedly show signs of deterioration. Buildings age before their time, and streets, sidewalks, and other infrastructure wear out sooner. Maintenance becomes harder to carry out. Property owners can be discouraged if flooding happens more than once or twice and begin to take shortcuts on some repairs, skip them altogether, or even move out and convert the building to a rental property, even if it has not been brought back up to its pre-damage condition. Some owners of repeatedly flooded properties walk away, letting the mortgage holders foreclose and resell or rent out the problem property. These approaches solve the current owner’s problem, but just pass the flooding threat on to others. Repeatedly flooded areas become undesirable places in which to live or work. Property values decline and the community’s tax base is diminished. Shallow stormwater flooding and drainage problems can have a ripple effect throughout the community’s economy, social fabric, environment, and quality of life. It is a good idea to step back from the situation, take a broad look at other community concerns or problems, and decide whether localized flooding is contributing to any of them. Are property values falling in some areas? Has a once-attractive stream become a place to dump garbage? Is the economy periodically disrupted? Legal Liability for Flood Problems When individuals receive damage from flooding or erosion they often file lawsuits against governments, claiming that the government has caused the damage, contributed to it, or (in some instances) failed to prevent or provide adequate warnings of the hazard. Such lawsuits are expensive for governments not only because damage awards are growing but also because of attorney and expert witness fees… Courts have often held governmental units liable for inadequately maintaining or operating culverts, bridge crossings, channelization projects, and dams. Kusler (2004) Has the fishing declined? Have environmental conditions been degraded? Are stream banks eroding and threatening homes or bridges? Do more storm sewers need repairs? All these seemingly unrelated issues may well be influencing, or be influenced by, a flooding problem. The advantage is that the solutions to the flood problem can be linked with solutions to other, perhaps more visible or popular, local concerns. They can even influence how well the community can sustain itself into the future. What Can Be Done Most of the time, the areas that receive shallow localized flooding are outside the community’s regulatory floodplain and thus are not subject to the zoning regulations and building standards that are in place in higher-risk areas. A community may feel that it can do only what the National Flood Insurance Program (NFIP) requires and that it has no regulatory jurisdiction or the power to enforce floodplain management requirements outside the SFHA. However, there are many examples of communities throughout the United States that have taken charge of their localized flooding problems instead of focusing solely on the SFHA and the minimum NFIP criteria. These communities have worked on their own to successfully resolve their localized flooding problems by tailoring solutions to their own needs, resources, and desires. The vital first step is for community officials and residents themselves to realize that they have a problem and that they can resolve it. Develop a Strategy An organized approach is always best, and developing a strategy does not need to be a large undertaking. The community’s approach to resolving a localized flood problem can be a formal plan, such as a community hazard mitigation plan, or it can be a simple decision to take a couple of visible steps in the right direction. Whatever is decided, the strategy should address the real needs and desires of the community, or at least those of the neighborhoods with flood problems. As detailed in Chapter 3 and Chapter 7, finding out what those concerns are lays the foundation for a plan that can be implemented successfully. Coordinate with Other Concerns A remedy for a flooding problem can also be a remedy for some other local concerns, and vice versa. Finding ways to combine solutions to these problems can be the key to simultaneously improving life in the community and alleviating flooding. Does the community/neighborhood need a park? A low-lying area converted to public space could fulfill that purpose and also provide needed storage for stormwater to alleviate flooding of nearby homes or businesses. Does the community/neighborhood need after-school activities for young people? Cleaning accumulated debris out of a stream channel and “adopting” it can minimize flooding and provide an educational experience for middle and high school students. Have residents or businesses in certain neighborhoods been asking for sidewalks? Combining the installation of this infrastructure with drainage works can make pedestrians safer and can also direct stormwater to a more appropriate location. Has the downtown area been declining? If it is flood-prone, a project to mitigate the flooding could support revitalization efforts, and vice versa. Orland Hills Solves its Flood Problems The Village of Orland Hills, Illinois, had a varied and widespread flooding and drainage problem that affected buildings, yards, and streets throughout town. Heavy rains caused water problems several times each year. The Village has a FIRM, but the mapped SFHA is relatively small and 82 percent is preserved as open space. The chronic flooding situations faced by Orland Hills residents were caused by local drainage problems. Regulating floodplain development and other traditional flood control approaches would not help. Accordingly, the Village created a Committee that prepared a Flood Protection Plan in 1995. It reviewed problems with maintenance of open ditches and detention basins. Many of the problems were preventable. In some areas, weeds and brush have been allowed to grow. Rocks placed as rip rap on the banks have been moved to the channel bottom, apparently by children. Figure 2-1 shows where the rip rap has been moved to plug a detention basin inlet. The worst problem in the channel is the condition of some of the culverts. As shown in the profiles, the culverts are so small that they act as dams even when clear. Over time, debris collects in them, rip rap is moved to block them, and they suffer from wear and tear. The pipes under 93rd Avenue have apparently separated, resulting in a hole in the overlying fill. Figure 2-2 shows this culvert and the barricade that has been placed over the hole. Flood Protection Plan, Village of Orland Hills, 1995, pp. 2-6–2-7. Village of Orland Hills Figure 2-1 Village of Orland Hills Figure 2-2 The Plan identified storm sewer backup and yard drainage as major causes of the continuing problems. The Plan also noted that many of the problems were caused by the owners themselves: Over the years, this drainage system has been disrupted. Many property owners are not aware of the need to keep their easements and swales open. They installed sheds, planters, railroad ties, or swimming pools in the easements. They built fences right on their lot lines to enclose the largest part of their properties. Figure 2-3 shows this process in one of the newest areas of Orland Hills. The low swale in the middle of the picture is being encroached upon by the new fences. Early homes in Orland Hills, especially homes on crawlspaces, were built at the original ground level. Later home builders, especially for tri-levels, added fill around the lots. This provided positive drainage from the lot, protected the lower areas from drainage problems, and improved the appearance of the site. Now when it rains, the runoff goes downhill to the lowest point: the older buildings that did not backfill or raise their lots. Directing downspouts and sump pump discharge pipes toward the property line aggravates the problem. Often the first property developed becomes the recipient of runoff as later builders fill in their lots. An example of this is seen in Figure 2-4. The Flood Protection Plan recommended a range of activities that have since been implemented: Tougher enforcement of easement restrictions; Passage and enforcement of a stream-dumping ordinance; Initiating a formal drainage maintenance program that inspects all ditches and storm sewers several times each year and after every heavy rain; Small scale projects to correct local problems, including televising storm sewers and rehabilitating broken ones; Site visits to determine the causes of local flooding problems and to advise property owners about what they can do; and A public information program that includes articles in the Village newsletter, annual letters to residents in problems areas, cable TV “crawlers,” and an annual public information campaign theme, such as “Don’t forget your drainage.” Since these efforts were started, Village staff report that the number of flooding complaints has decreased dramatically. They noted that some easement and dumping violations were reported by neighbors, a sign that the public information activities were paying off. In 1996, Orland Hills joined the NFIP Community Rating System (CRS). Village officials found CRS materials helpful in designing their program and the annual reporting requirements helpful reminders to keep their programs going. They note that there are more advantages to the CRS than the direct financial reward to the policyholders. Orland Hills is currently a CRS Class 5, one of the best in the nation, even though there are only 22 flood insurance policies in the Village. Village of Orland Hills Figure 2-3 Village of Orland Hills Figure 2-4 Pick an Activity and Do It Start with an action item listed in the plan or strategy that is easy, or inexpensive, or can be added on an existing activity. An early success will give people a sense of accomplishment and encourage moving on to the more difficult or complicated tasks. After that, priorities will have to be set by the community based on identification of the most visible problems and the resources that are available, as well as other factors. The area analysis process described in Chapter 7 offers some ideas of the factors to be considered in setting priorities. Any initiative will fall into one of the three general categories of approaches listed below. These are based on the scale of the area and number of people affected, going from broad to narrow. The rest of this guide is organized according to this scheme. Organize community-wide activities (Part II of this guide) to make a broad impact and/or obtain wider support. This includes local planning and bolstering the capabilities of community staff (Chapter 3); and assessing regulations, mapping, building standards, zoning, and other techniques that apply to the whole community, even if there are different provisions for certain areas (Chapter 4). Public awareness and education campaigns (Chapter 5) and flood warning systems and emergency services (Chapter 6) also are best handled at the community level. Tackle each neighborhood problem area individually (Part III). In many cases, several homes and/or businesses suffer flood problems for the same reason, whether it’s their location in a low-lying area or an inadequate storm drain or culvert. The local government will probably be the entity to carry out neighborhood-level projects or programs, but involving residents as much as possible is essential. The area analysis recommended in Chapter 7 encompasses this idea. Neighborhood associations or even ad hoc groups of property owners can be a big help in spreading the word, developing ideas, and garnering citizen support for changes such as drainage improvements (Chapter 8) and even redevelopment (Chapter 9). Deal with individual buildings. The flood risk to some flood-prone structures cannot be mitigated through a community-wide or neighborhood-level approach. These buildings need special attention to make them resistant Solving Localized Flooding— Value Added Property and neighborhoods are preserved and often improved. The lives of residents and emergency personnel are protected. Fewer floods mean fewer opportunities for injuries and accidents to occur. The health of community residents is safeguarded; unhealthy and stressful situations are minimized. The economic viability of the community is maintained. Disruption and economic losses from flooding are reduced or eliminated. Business interruptions and permanent closures are minimized. Public (local) costs of flood response and recovery are reduced or eliminated. Property values and the local tax base are preserved. Legal liability is minimized. Credit for certain activities can be obtained under the CRS, resulting in lower insurance premiums for all flood insurance policyholders in the community. Even policyholders outside the SFHA receive a 5 to 10 percent reduction in their premiums. Making progress, and especially participating in the CRS, provides both an incentive for more organized and permanent local floodplain management, stormwater drainage, public awareness, and other activities. to flooding. Another reason to work on a single-building basis is that convincing one property owner to take protective measures for his or her property may well induce others in the area to follow. Often people are hesitant because they don’t know what the finished product will look like or because they are unfamiliar with the problem or the techniques that can solve it. An individual success can induce others to take action and lead to a bigger project, if needed. Part IV explains the best techniques to use on individual structures, namely, retrofitting (changing a building or part of it to make it more resistant to flood waters) in Chapter 10, and flood insurance, discussed in Chapter 11. Join or Advance in the Community Rating System Under the NFIP Community Rating System (CRS), a community receives a classification based upon credit points that are awarded for conducting activities to reduce flood losses, such as better mapping, stronger regulations, public information campaigns, flood damage reduction projects, and/or flood warning and preparedness programs. The credit points earn reductions in flood insurance premium payments for all NFIP policyholders in the community, even those outside the floodplain. But participating in the CRS is not just about saving people money. Belonging to the CRS provides an incentive not only to start new flood mitigation activities, but also to keep them going. A CRS community must recertify each year that it is continuing the activities for which it receives credit. The recertification is a simple procedure, but it serves to keep local attention focused on the importance of these ongoing activities. Further, in the process of applying for the CRS, a community receives help on and feedback about parts of its flood reduction program, which improves staff expertise and generates new ideas. Some communities say that the CRS has changed the way their programs work, even without budget increases. Because there are 10 levels (classes) in the CRS, even communities that already participate can benefit from undertaking additional flood-related activities. They will receive greater premium discounts and can take advantage of the expert assistance, information, and contact with other communities. Where to Get Help The Community Rating System Web site is http://training.fema.gov/ emiweb/CRS/. The Web site of the Association of State Floodplain Managers (ASFPM) is http://www.floods.org. Information on the NFIP can be viewed at http://www.fema.gov/nfip/. Examples of how localities have solved flood problems can be found easily on the Web. Search for “mitigation success” or go to http://www.floods. org/Publications/mitsuccstories/mssiii1.htm. Additional resources are listed in Appendixes A and B. The CRS has made the Village think more proactively about stormwater management, instead of just waiting for the next big rain. — Gary Salavitch, Village of Hoffman Estates, Illinois The Community Rating System The CRS rewards communities for what they are doing to reduce flood losses and also provides an incentive for new flood protection activities. The reward is a reduction in flood insurance premium rates. A community’s efforts are rated and identified by a CRS classification, with an accompanying discount on the annual premiums for policyholders in the community (see table below). Application. To apply, a community submits worksheet pages from the CRS Application that show what it is doing and that its activities earn at least 500 points. After the activities are verified through a field visit, The Federal Emergency Management Agency (FEMA) sets the credit to be granted and notifies the community, the State, and insurance companies of the rating. Recertification. Each year the community must recertify that it is continuing to perform the activities that are being credited by the CRS, and submit documentation in the form of copies of projects conducted during the year, progress reports, and similar items. Community Responsibilities. A community in the CRS must: Designate a CRS Coordinator; Cooperate with the verification of its credited activities; Continue to implement its activities, and certify each year that it is doing so, with appropriate documentation; Advise FEMA of modifications to its activities; Address any identified repetitive loss issues; Maintain elevation certificates, other permit records, and old FIRMs forever; and Maintain other records of its activities until the next verification visit. CRS Activities. The CRS credits a range of local (and State) activities that operate to reduce flood losses, promote flood insurance purchase, and facilitate accurate insurance rating. The four main categories and 18 creditable activities are listed in the box below. Information. Technical assistance is available for communities applying for and participating in the CRS. No fees are charged for application, publications, or participation. The CRS Application, the CRS Coordinator’s Manual, and all other CRS publications are free and can be obtained by calling 317-848-2898 or e-mailing NFIPCRS@iso. com, or downloaded from http://training.fema. gov/emiweb/CRS/. CRS Activities 300 Public Information Activities 310 Elevation Certificates 320 Map Information Service 330 Outreach Projects 340 Hazard Disclosure 350 Flood Protection Information 360 Flood Protection Assistance 400 Mapping and Regulatory Activities 410 Additional Flood Data 420 Open Space Preservation 430 Higher Regulatory Standards 440 Flood Data Maintenance 450 Stormwater Management 500 Flood Damage Reduction Activities 510 Floodplain Management Planning 520 Acquisition and Relocation 530 Flood Protection 540 Drainage System Maintenance 600 Flood Preparedness Activities 610 Flood Warning Program 620 Levee Safety 630 Dam Safety Credit Points CRS Class Credit SFHA* Non- SFHA* A99/AR Zones 4,500+ 1 45% 10% 10% 4,000 - 4,499 2 40% 10% 10% 3,500 - 3,999 3 35% 10% 10% 3,000 - 3,499 4 30% 10% 10% 2,500 - 2,999 5 25% 10% 10% 2,000 - 2,499 6 20% 10% 10% 1,500 - 1,999 7 15% 5% 5% 1,000 - 1,499 8 10% 5% 5% 500 - 999 9 5% 5% 5% 0 - 499 10 0 0 0% CRS Classifications * SFHA: the floodplain shown on the community’s FIRM. Reducing Damage from Localized Flooding: A Guide for Communities Part II Community- Level Tools and Techniques The first part of this guide reviewed the problems created by localized flooding and the reasons why a community should take actions to protect people and property from the hazard. Chapter 2 noted that actions can be taken at three different levels: community-wide, neighborhood, and individual structures. Part II addresses the broadest of these levels: techniques for coping with flooding that are appropriate for community-wide action. First, Part II describes a community planning process that will help determine and build support for appropriate flood mitigation activities. It will also meet the planning prerequisite for several Federal funding programs. Next, various regulations are discussed that a community can apply to its flood-prone areas. The usefulness and potential of public information campaigns and projects are presented. Finally, Part II explores what a community should do to improve its warnings for localized flooding, as well as its preparedness for a flood emergency. Part II: Chapter 3. Community-Level Activities Chapter 4. Regulatory Tools Chapter 5. Public Information and Awareness Chapter 6. Warning and Emergency Service Reducing Damage from Localized Flooding: A Guide for Communities 3-1 3 Community- Level Activities This chapter reviews the three parts to organizing community-level activities: (1) determining an overall strategy, (2) preparing a more detailed plan, and (3) building capabilities to implement flood-protection actions. As used in this guide, a “community” is any city, village, town, county, or other local government with authority to enact floodplain management measures. The Strategy A community should have an overall strategy that outlines how it will address its localized flooding problems. It may be as simple as doing nothing or funding drainage improvements in response to complaints. The more the community intends to do, the more involved the strategy must become. The Document Many communities have unwritten strategies or strategies that change when leadership changes. To be effective, the strategy should be written. A written document provides a clear statement that will be consistent over time. It also shows how individual actions fit in the bigger picture. The best approach would be a document adopted by the governing board, such as a resolution. A strategy or resolution can be as short as one page. No special format is needed, but it should recognize that there is a problem and identify the key policies and actions that will be pursued. An example is on pages 3-4 and 3-5. Circulating a draft for comments by the appropriate staff will help gain their support and ensure that the policies and actions are realistic. Strategy Statements Strategy statements will depend on the problems, resources, and the community’s level of commitment to take action. Examples include: Chapter 3. Community-Level Activities PART II Reducing Damage from Localized Flooding: A Guide for Communities 3-2 All reports of localized flooding problems will be investigated by municipal engineering, utility, or public works staff to determine the cause and most appropriate solution. New buildings constructed in flood problem areas must be protected to the highest recorded flood level, even if they are not in the Special Flood Hazard Area (SFHA) mapped on the community’s adopted Flood Insurance Rate Map (FIRM). Land development regulations will be reviewed to determine if revisions would help prevent localized flooding problems or exacerbate existing problems in the future. All residents in areas with localized flooding problems will be encouraged to purchase and maintain flood insurance. All buildings will be constructed with positive drainage away from the building. The rest of the chapters in this book can be used as a checklist to identify actions that can be pursued by the community and included in the strategy document. The more time spent reviewing what should be done, the more detailed the strategy can be. However, there comes a point at which the level of detail is sufficient for the community plan to be prepared, reviewed, and adopted. Long-Term Strategies Some communities have short-term and long-term strategies. Short-term strategies might include small-scale drainage modifications and encouraging people to buy flood insurance. The long-term strategy could be to prepare a flood mitigation plan that sets out a more comprehensive approach to the problem. A Community Plan A community-level plan is more formal and detailed than a strategy statement. It summarizes the problem(s), sets goals, reviews alternative actions, and selects those actions that will best reduce the problem. It is a systematic and thorough review of what can be done. It should take more time and involve more people than a simple strategy. Benefits A well-prepared plan will: Ensure that all possible activities are reviewed and implemented so the local problem is addressed by the most appropriate and efficient solutions; Ensure that individual activities are coordinated with other community goals and activities, preventing conflicts and reducing the costs of implementing each activity; Coordinate local activities with Federal, State, and regional programs; Chapter 3. Community-Level Activities PART II Educate residents on flood problems, flood insurance, and loss-reduction measures; Build public and political support for mitigation projects; and Fulfill planning requirements for State or Federal mitigation grant funds. The Process Plans can come in a variety of formats and organizational styles. The format and organization of a plan is not important, but the process of planning is. The planning process provides a framework within which planners, local officials, residents, engineers, technical experts, stakeholders, and others can work out the details and reach a consensus on what should be done. The process works for all types of plans, such as comprehensive plans, land use plans, capital improvement plans, neighborhood redevelopment plans, hazard mitigation plans, stormwater management plans, and floodplain management plans. Planning Guidance The Federal Emergency Management Agency (FEMA) has published various guidance documents over the years, and they all agree on four basic phases to developing a mitigation plan: Organize for the effort and involve affected parties, especially the public; Assess the hazard and the community’s exposure to damage by the hazard; Set goals and review and select appropriate measures to reach those goals; and Adopt, implement, evaluate, and revise the plan periodically. There are four FEMA programs with planning criteria: the three major flood mitigation funding programs require a plan as an application prerequisite, and the Community Rating System (CRS) has credit criteria for floodplain management planning. The chart on page 3-6 shows that the planning process the community uses can meet the prerequisites of all these programs. These programs have published guidance documents that are listed in the last section of this chapter. Furthermore, flood control assistance from the U.S. Army Corps of Engineers also has a floodplain management plan requirement. The Corps of Engineers’ guidance states that a plan that meets the CRS criteria under Floodplain Management Planning, Activity 510, will fulfill this requirement. The City of Conway, South Carolina, was severely flooded by Hurricane Floyd in September 1999. The Waccamaw River and its tributaries flooded areas that were mapped as X Zones on the community’s FIRM. Acting quickly, before the waters receded, the City Council passed a resolution that spelled out its strategy: All properties, including those not in the SFHA, would be inspected and subject to the same reconstruction requirements. A mitigation plan would be prepared to identify a long-term solution. Residents would be helped with information and financial assistance. The resolution appears on the next two pages. One planning effort can meet the community’s needs and meet the criteria of several different programs, including hazard mitigation grants, the CRS, the Natural Resources Conservation Service, and the Corps of Engineers’ project prerequisite. Planners should review the criteria of each program to ensure that their efforts will qualify for all the programs’ benefits. Resolution by the City of Conway, South Carolina, After Flooding from Hurricane Floyd in 1999 WHEREAS, properties along the Waccamaw River and its tributaries in the City of Conway have been severely flooded, are currently uninhabitable, and according to the best available information, may be substantially damaged; WHEREAS, the floodplain ordinance of the City requires substantially damaged residences to be either elevated or demolished and either option can place a hardship upon the owners; WHEREAS, the City Council has discussed various alternative ways to redevelop the area but none has yet been reviewed in depth and none has been based on full knowledge of the condition of the buildings or the desires or financial conditions of the owners; and WHEREAS, several of the redevelopment alternatives reviewed to date may conflict with each other, may jeopardize the availability of flood insurance to residents, and/or may not be in the long term best interests of the residents or the community; NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Conway that: It is the policy of the City of Conway to: Keep the City in good standing in the National Flood Insurance Program to ensure that all residents can obtain financial assistance and flood insurance to protect their properties from flood damage; Not allow any reconstruction or reoccupation of flooded buildings or homes until the City Building Official or his duly authorized representative has inspected the site and issued a building permit; Carefully develop a mitigation plan for the affected area after a review of all options (including flood control, reconstruction, elevation, floodproofing and relocation) based on building conditions, the desires of the property owners, and funding sources that are available to assist the property owners; and Assist residents with information on relocation and other flood protection measures and help them obtain financial assistance. To implement this policy, be it hereby resolved that: Every building that has been flooded must have an inspection by the Building Official or his duly authorized representative before it is repaired or reoccupied. If the level of damage is minor, the Building Official may issue a letter saying that clean up may proceed without a permit. There is no fee for such inspection or for the subsequent permit to repair or rebuild a flooded building. A Mitigation Planning Committee is hereby established. Its members shall be: (The City of Conway citizens’ names have been removed, but their representation on the committee is the following) Chair – banker, floodplain resident and former city manager Vice-chair – floodplain resident Floodplain resident Floodplain resident Floodplain resident Council member, floodplain resident Council member, floodplain resident Director of Planning Building official, floodplain resident Floodplain resident Grants/special projects coordinator Floodplain resident The Mitigation Planning Committee is charged with the following: (continued on facing page) Building Capabilities Once the strategy has been decided or the plan has been drafted, the community should prepare to implement it. A formal plan will identify who is responsible for each action item, when it will be accomplished, and what will be the source of funding. A strategy may not be so specific; however, certain activities should be pursued in a strategy. Assign Staff Responsibilities An activity identified in a strategy or an action item in a plan will not be implemented if no one is responsible for it. The strategy resolution or the mayor should designate offices or individual staff members as the lead for each activity. In most cases, the responsibility will be obvious: the public works department is responsible for drainage maintenance and the planner is responsible for plans. The discussion in the following chapters includes typical contacts and responsible offices for the various mitigation tools and techniques. Collect data on building conditions, the desires of the property owners, and funding sources for reconstruction and redevelopment in the flooded area; Recommend reconstruction and redevelopment policies and procedures to be followed by the City; Identify particularly hard hit areas that could be designated as target areas appropriate for acquisition, clearance and conversion to open space; Prepare a post-flood hazard mitigation plan for the City that designates target areas and recommends mitigation measures appropriate for the flood hazard facing the City; and Keep the public informed of its deliberations and recommendations. Upon the advice of the mitigation planning committee, the City Council may adopt a moratorium to prohibit reconstruction of buildings in certain target areas until the mitigation plan is adopted. Owners of property in the affected area are encouraged to: Attend public meetings to review the City’s mitigation planning activities and recommendations; Cooperate with the building inspectors in order to help determine the condition of their buildings and to collect accurate data as quickly as possible; and Assist in the preparation of the mitigation plan by providing information on the condition of their buildings and whether they are interested in relocating to a flood free location. Passed this 27th day of September 1999. (continued from page 3-4) FEMA 386-3 (2000, p. xi) The planning requirements and processes that are used for FEMA programs and described in various guidance documents coincide as shown in this chart. It should be noted that a CRS publication, Example Plans, provides guidance that will meet all three programs’ criteria. It is available at http://training.fema.gov/emiweb/CRS/. Educate Staff Although it may be obvious that the planner is responsible for plans, the community’s planner may not be familiar with flood mitigation planning. There are many publications and training programs, as well as references in this guide, that can help educate or train staff on flood protection tools and techniques. Get Help A community should not duplicate the efforts of others. Nor should it try to solve all its problems by itself. Other government agencies and private organizations may be implementing activities that can affect flooding in the community. Many agencies and organizations can provide: Flood hazard data and maps; Technical information on flood mitigation tools and techniques; Guidance on regulatory requirements; Advice and assistance in the planning effort; Staff training; Implementation of an activity; and/or Financial assistance. The lists in Appendixes A and B give agencies, organizations, and other resources that can be consulted for help in planning and conducting local flood mitigation activities. Help can also be hired. A community may turn to a consultant if it concludes that: It does not have enough staff; It does not want to hire staff for a short-term project; or It wants help from someone with specialized knowledge. At the end of each chapter of this guide is a section called “Where to Get Help,” which lists relevant and helpful agencies and organizations. Those entities should be contacted for assistance or for information on qualified consultants who can help the community’s efforts. Integrate Activities The best way to ensure that an activity will be implemented is to incorporate it into existing programs and activities. If staff members modify their work or accept assignments as part of their regular duties, the activity will become part of the community’s routine responsibilities. Integrating the flood protection tools and techniques into ongoing activities also reduces the financial impact on the community. The integration of activities is discussed in the chapters that follow. Examples include: Modifying subdivision regulations to include stronger drainage and stormwater management standards, rather than adopting a new set of regulations; Adding flood protection topics to water quality public information materials instead of creating and printing new brochures; Coordinating park and open space planning with floodplain property acquisition efforts, using Federal mitigation funds to help expand recreation lands; and Using experienced housing rehabilitation staff to provide retrofitting advice and/or administer retrofitting financial assistance funds. Evaluate A periodic review of activities included in the strategy or plan can be helpful. The community should determine if the activities are being implemented and, if so, whether they are effective. At the same time, the basis for the strategy or plan should be evaluated to determine if they are still relevant and whether new activities are needed. Periodic monitoring, evaluating, and, if necessary, revising the activities recommended by a floodplain management or hazard mitigation plan are requirements of the FEMA planning programs. They are good measures to include in a strategy. Where to Get Help FEMA’s Planning Resource Page at http://www.fema.gov/fima/planresource. shtm. Flood Mitigation Planning—The First Steps, Association of State Floodplain Managers (ASFPM), 2001, is a floodplain management planning kit consisting of reference materials, masters that can be duplicated for handouts, and a 2-part video that explains the 10-step process to the general public. It is designed to be shown at the first meeting of a planning committee. Order through the ASFPM Web site at http://www.floods.org or call 608-274-0123. FEMA Regional Offices (see Appendix A). A Planning Success Story After a flood in 1990, Village officials of South Holland, Illinois, were faced with many angry residents who were convinced that the Village was not doing enough to protect them from flooding. The Village formed a Flood Liaison Committee so residents and staff would work together. The Committee spent a year preparing a floodplain management plan that reviewed all the alternatives and recommended 31 action items. The Village began providing technical assistance and a floodproofing rebate program that has helped fund 450 self-help retrofitting projects to protect homes from local flooding. Residents are now active participants in the Village mitigation program. South Holland has since received one of the highest ratings in the CRS (Class 5), has received state and national awards, and has played a lead role in the initiation of a watershed-wide flood and stormwater mitigation planning effort. The Flood Liaison Committee still meets to provide oversight of the staff’s activities and to monitor, evaluate and recommend revisions to the plan. Wetmore and Jamieson (1999) State National Flood Insurance Program coordinating office and the State emergency management agency’s mitigation office can be located at http:// www.floods.org/StatePOCs/map.asp and http://www.fema.gov/fema/ statedr.shtm, respectively. American Planning Association at http://www.planning.org. The Insurance Services Office (ISO) administers the Community Rating System on behalf of FEMA. For technical assistance in preparing a floodplain management plan, contact NFIPCRS@ISO.com. Publications and other information about the CRS, including its planning components, are available at http://training.fema.gov/emiweb/CRS/. Regional planning commissions and councils of government often help communities with planning or prepare plans for them. Training courses in floodplain management, flood insurance, the CRS, building protection, and other matters are offered by the Emergency Management Institute. Tuition is usually free to local government staff. The schedule and course descriptions can be found at http://www.fema.gov/ emi/. If there is a State-level professional association for floodplain managers, wetlands managers, stormwater managers, or others, it can be a resource for technical training opportunities for local staff. Floodplain management associations can be found at http://www.floods.org/StatePOCs/stchoff.asp. The State emergency management agency can be contacted for technical training schedules for local staff. Three FEMA programs provide financial assistance for flood or hazard mitigation planning on a 75%/25% cost share: Flood Mitigation Assistance program (FMA) Pre-Disaster Mitigation program (PDM) In the PDM grant program, special consideration will be given to small and impoverished communities and they may be eligible for a 90%/10% split. Hazard Mitigation Grant Program (HMGP). The State emergency management agency and the FEMA Regional Offices have more information about these funding programs. (Note that the Flood Insurance Reform Act of 2004 has a special provision under which the cost share for mitigating repetitive loss properties may be 90%/10%, but regulations to implement this change have not yet been finalized.) Many States have prepared their own floodplain management or mitigation planning guidance. It is usually found at the State’s emergency management or National Flood Insurance Program (NFIP) coordinating office. The user should verify that the State guidance includes the latest criteria from the CRS Coordinator’s Manual and the Disaster Mitigation Act of 2000. Additional resources are listed in Appendixes A and B. Reducing Damage from Localized Flooding: A Guide for Communities 4-1 4 Regulatory Tools In almost all cases, it is less expensive and less disruptive for a community to prevent flood problems from occurring than to mitigate problems that already exist. Regulatory tools can be designed to protect new buildings from flooding and to prevent new development from creating new or aggravating existing flood problems. The National Flood Insurance Program (NFIP) and its Community Rating System (CRS) are good starting points for reviewing regulatory tools. To participate in the NFIP, communities are required to adopt and enforce regulations to manage new development in the Special Flood Hazard Area (SFHA) shown on the Flood Insurance Rate Map (FIRM). As noted in Chapter 2, significant damage can occur in the areas outside the SFHA in the B, C, and X Zones. To prevent new development from making its localized flood problems worse, a community needs to do more than just enforce its NFIP regulations. The many regulatory tools that help minimize flooding and flood damage are discussed under the five main sections of this chapter: Adopting a map showing additional flood-prone areas to be regulated; Planning and zoning for appropriate development in flood-prone areas; Setting standards for new subdivisions; Setting standards for new buildings in flood-prone areas; and Regulating site drainage. A Regulatory Floodplain Map The first step in managing new construction to protect it from flood damage is to determine what areas are subject to regulation. The NFIP has published the community’s FIRM, but this should be considered as only a beginning. The regulatory floodplain on the FIRM may not adequately identify all of a community’s at-risk Chapter 4. Regulatory Tools PART II Reducing Damage from Localized Flooding: A Guide for Communities 4-2 areas. There are several reasons why some local flooding areas may be missing from the community’s FIRM. Smaller problem areas do not show up as SFHAs because Federal Emergency Management Agency (FEMA) mapping standards focus on larger flood problems, such as watersheds larger than 1 square mile. Conditions may have changed since the study was conducted to produce the FIRM, which could have been as long as 10 or 20 years ago. When the FIRM was prepared, an area may not have been known to have a flood problem or it may not have had much development activity, so it was not studied. The study criteria may not have reflected all types of flood-related hazards, such as land subsidence. In short, FIRMs cannot be expected to show every flooding problem in the community, especially flooding caused by local drainage or storm sewer problems. However, because these problems are more frequent than the major flooding shown on the FIRM, and because the drainage or sewer system is a local responsibility, it is likely that the community has additional information that could be used to supplement the FIRM’s presentation of the community’s flood hazard. Communities can do much to provide a better floodplain map and regulatory data. This section explains four valuable options for improvement: Use more accurate elevation contour information to map flood elevations provided with the FIRM; Restudy local flood-prone areas and produce a new regulatory floodplain map; Require permit applicants to provide needed flood data; and Develop new flood hazard maps and data using more exacting study techniques. More Accurate Contour Map When a community’s FIRM is prepared, the study contractor uses the best base map available at that time. In many cases, it could be a U.S. Geological Survey quadrangle map with a 5- or 10-foot contour interval. Since their FIRMs were prepared, many communities have developed geographic information systems (GIS), often with more recent and more accurate elevation data. A community should check to see if there is a new base map with more accurate topography. This could be the product of recent surveying, analysis of ortho-rectified aerial photos, or light detection and ranging (LIDAR) (the use of an airborne laser In Activity 410 (Additional Flood Data), the CRS encourages and provides credit for several mapping activities: Providing regulatory flood elevations in X and approximate A Zones; Restudying and remapping areas shown on the FIRM; Requiring developers to produce regulatory flood elevations in smaller watersheds; and Studying hydrology based on future watershed conditions. Chapter 4. Regulatory Tools PART II system to prepare topographic maps). Such a base map may have recently constructed roads, bridges, and other human-made features, 1- or 2-foot contour intervals, or contour information that is more accurate or more recent than that used to prepare the FIRM. If there is a more accurate and more recent contour map, the 100-year flood elevations from the Flood Insurance Study’s flood profile should be plotted on it. Such an exercise may well reveal that the boundaries of the SFHA should be different. Gurnee, Illinois, found this to be true, as depicted in the adjacent map. Many times, such a review finds that the FIRM understates the true inundated area and the SFHA should be extended into the X Zone. If this is the case, it is recommended that the community adopt this more accurate map in its floodplain management regulations. Another approach is to record the high-water marks and note the areas flooded if a recent flood extended outside the boundaries of the SFHA. That is what the City of Conway, South Carolina, did after Hurricane Floyd sent the Waccamaw River flooding into its X Zone in 1999. The city adopted the area flooded by Floyd as its new regulatory floodplain (see page 4-5). A third approach to capture more of the flood-prone areas is to regulate the mapped floodplain plus all areas 1 foot higher than the base flood elevation (BFE). Development on properties outside the SFHA, but within 1 foot of the BFE, would need a floodplain permit. If the developer produces accurate ground elevation data that show the building site above the BFE, the floodplain regulations would not apply. A variation on this approach is to regulate to the next higher contour line. For example, a site located between a BFE of 145 and one of 146 would be mapped at the 146 contour line. A disadvantage of this method is that elevations are not increased by a constant amount (for example, 145.1 and 145.9 both round to 146). New Flood Study Using more recent or more accurate elevation data is a relatively inexpensive way to get a better flood map from existing flood data. Another approach to getting a new floodplain map is to conduct a new flood study Gurnee, Illinois, put its FIRM flood elevations onto a more accurate base map and found these differences, identifying other areas that could be susceptible to flooding. New Maps vs. FIRM Adoption of a different map in the local ordinance is allowed by the NFIP regulations, provided the new map covers a larger floodplain than the FIRM does. In fact, exceeding the NFIP minimum criteria is encouraged by FEMA. However, two things should be noted: The community’s map will not affect the current FIRM or alter the SFHA used for setting insurance rates or making map determinations. Under 44 Code of Federal Regulations 65.3, as “soon as practicable, but not later than six months after the date such information becomes available, a community shall notify [FEMA] of the changes by submitting technical or scientific data….” The State NFIP Coordinator or the FEMA Regional Office should be contacted for instructions on how this is done (see contact list in Appendix A). to produce new flood data. The new study could either cover the same area mapped as SFHA on the FIRM or areas outside the SFHA that have been known to flood or have repetitive flood problems. In the SFHA, the community’s new study must use the same or similar study techniques as for a detailed study on a FIRM. These techniques can be expensive, but the study may help with activities other than regulations. As noted in Chapters 8 and 10, a new flood study and watershed model can help greatly when planning drainage modifications or selecting a design protection level for a retrofitting project. Typically, FIRMs do not include the floodplains of streams with a drainage area of less than 1.0 square mile in urban areas and even larger drainage areas in rural areas. Therefore, if there is a localized flood problem that should be mapped in order to guide development regulations, the area will most likely have to be studied by the community. If the area is outside the SFHA, the community can use any technique it prefers. Areas not previously studied have no minimum standards. Probably the least-expensive approach is to use the flood of record, i.e., to map out the areas that were under water during the highest recorded flood. Communities that use this approach usually add a safety margin of a foot or two to the flood-of-record’s crest as the basis for a regulatory flood elevation. It should be noted that using historical floods does not necessarily treat everyone the same. In some areas, the historical flood of record may be the 100-year flood, but in other parts of a community, it may be the 25-year flood. It is especially difficult to be consistent when some areas were developed in the last 10–20 years, so there is a relatively short history of known flood problems. FEMA encourages a community to provide more accurate flood data to revise its FIRM. In fact, the Cooperating Technical Partners (CTP) program is a formal mechanism through which communities can cooperate on new flood studies or provide flood data that may differ from FEMA mapping criteria. FEMA is working to prepare more new flood studies. Its Map Modernization Program has a goal of helping all communities update their FIRMs by the year 2008. Congress is allocating significant additional funding for these efforts. In other words, under the CTP program, FEMA wants to work more closely with communities to better delineate their flood hazard areas, and under Map Modernization, FEMA is expected to be able to increase its new study effort. FEMA has also provided guidance and developed software to facilitate flood studies and reduce their cost. Managing Floodplain Development in Approximate Zone A Areas can be ordered from FEMA or downloaded from its Web Cooperating Technical Partners In conjunction with the Map Modernization Program, FEMA establishes partnerships with participating NFIP communities to collaborate in maintaining up-to-date flood maps and other flood hazard information through the CTP program. Under the CTP program, a community and FEMA work as partners to more efficiently and effectively update flood hazard maps. This ensures that local knowledge about flood problems, local sources of data, and local preferences for study priorities are all incorporated into the process. The CTP program brings funding for eligible activities, such as topographic data generation, hydrologic and hydraulic analyses, Digital FIRM (DFIRM) creation, and others. More information can be found at FEMA’s Web site at http://www.fema.gov/fhm/ctp_main.shtm. Conway Remaps after Floyd Hurricane Floyd flooded places in the City of Conway, South Carolina, that were outside the mapped SFHA of the Waccamaw River and its tributaries. The map below shows that many properties in the X Zone were flooded with water over 2 feet deep. Many flooded property owners did not have flood insurance because they were not in the designated SFHA. Conway reviewed the discharges and elevations from past floods. The chart below summarizes these data, showing that the Hurricane Floyd flood in 1999 had practically the same discharge as the 100-year or base flood used for the city’s FIRM. However, the elevation of the flood was 1½ feet higher. There had also been a flood in 1928 with the same discharge and elevation as in 1999. * Property where the 1999 flood was over 2 feet on the outside wall of the building. V Properties with a “V” and no address are vacant. Waccamaw River at Conway Date of Crest Estimated Peak Discharge (cubic feet/ second) Elevation (NGVD)* (feet) October 1924 15,400 10.45 September 1928 22,000 12.75 September 1945 15,500 10.55 March 1959 8,800 7.75 July 1961 9,600 8.05 February 1973 9,900 8.35 December 1994 8,630 8.00 September 1996 12,000 9.15 February 1998 14,800 9.60 September 1999 22,400 12.55 Base Flood (modeled) 22,310 11.10 * National Geodetic Vertical Datum Conway opted to use the Hurricane Floyd flood elevations for its floodplain management regulations. The area affected by Floyd became the regulatory floodplain. The city subsequently requested a revision to its FIRM in order to allow the flooded properties to become eligible for mitigation funding assistance and to inform future purchasers of property of the true flood hazard. Flood Hazard Mitigation Plan, City of Conway, South Carolina (2000) site. It includes instructions on using the Quick-2 program, which can help calculate a BFE without conducting an expensive on-site flood study. Permit Requirements The greatest obstacle to preparing a new flood study is the cost. There is a rationale that says that if someone wants to build in a flood-prone area, he or she should bear all the costs of developing there, including paying for any needed flood data. The NFIP requires that in approximate A Zones (mapped floodplains where FEMA did not provide a flood elevation), anyone who develops more than 50 lots or 5 acres must provide the needed data. This rationale is appropriate in all flood-prone areas for all sizes of development. Some communities require developers to: Identify all streams and watercourses that flow through or adjacent to the property; Determine the size of the contributing drainage area; and If the drainage area exceeds a certain threshold, provide the BFE (and in some cases delineate a floodway). An example of this approach is the City of Tulsa, Oklahoma. Tulsa requires all development in drainage areas as small as 40 acres to conduct a study to show the 100-year floodplain and floodway. All areas smaller than 40 acres must have a combination of storm sewer and overland drainage so that a 100-year storm will not cause any building to flood. In Prince George’s County, Maryland, developers are required to delineate the floodplain for streams that drain 25 acres or more. This approach can also be used if the community has identified flood-prone areas of concern, such as those that have been repetitively flooded in the past. If such areas are delineated based on available historical data, developers could be required to conduct a study to produce a regulatory flood elevation before they are permitted to build there. Study Standards Although the FIRM floodplain boundaries are the regulatory boundaries initially provided by FEMA, communities can consider using higher standards when mapping a flood-prone area. This would apply to any of the previous conditions: restudying an existing SFHA, preparing a new study, or requiring developers to prepare regulatory flood data. (Note that a community should modify its ordinance to have the authority to require that these higher study standards be used.) Lake County, Illinois, regulates many flood problem areas outside the SFHA shown on its FIRM. These include: “Flood table lands,” areas within 2 feet of elevation of a floodplain for a stream that drains more than 100 acres; Depressional storage areas with a storage volume of 0.75 acre-feet or more for the base flood; and Non-riverine depressional floodplains and wetlands of any size. Permit applicants must have an engineer calculate the BFE in these areas. In non-riverine areas, the historic flood-of-record elevation plus 3 feet can be used instead of conducting the detailed study. The full language of the county’s Watershed Development Ordinance can be found at http://www.co.lake.il.us/smc/regulatory/ wdo/. The most common higher study standard is known as future-conditions hydrology. Under FEMA mapping standards, the flood elevations on FIRMs are based on land use conditions existing at the time of the study (which may have been a decade or more in the past). If significant development occurs in the watershed, the hydrology (i.e., how much water comes from the watershed) will be outdated and will likely understate the true flood hazard. To prevent studies from becoming outdated as new development alters the watershed and the hydrology, communities can take two approaches: (1) require that new developments in the watershed include storage basins to store the excess stormwater, or (2) conduct studies that are based on future watershed conditions. Many communities use both approaches. Stormwater storage basins are discussed on page 4-14. Mapping based on future watershed conditions is especially useful where a community does not have regulatory authority over the watersheds outside its corporate limits. One of two common approaches is used: Assume that the watershed is developed according to a long-range land use plan; or Assume that runoff comes from a fully urbanized watershed. Future-conditions hydrology and other higher standards will usually result in larger floodplains and higher flood elevations than are shown on the FIRM. Using such data has several benefits: New construction will be better protected against flood damage; There will be fewer requests for FIRM revisions; Flood insurance rates will be lower for new buildings as a result of higher standards; and The community can receive CRS credit. Land Use Regulations Once the flood-prone areas are shown on a community-adopted map, the community can use several techniques to prevent new development in those areas from being subject to flood damage and from aggravating existing flood problem(s). Three general approaches are covered in the rest of this chapter: Land use regulations to guide development away from the flood-prone areas; Regulations on new infrastructure, such as drainage systems; and Regulations on construction of individual buildings. There are two basic tools to regulate the use of land: a land use plan and a zoning ordinance. These tools designate where low-, medium-, and high-density residential development and industrial and commercial development should go. These tools are Anne Arundel County, Maryland, has a “48- inch pipe rule,” which requires that the 100-year floodplain be delineated for a stream if a 10- year ultimate land use discharge cannot be conveyed within a 48- inch reinforced concrete pipe at the natural ground slope. Anne Arundel County, Maryland, Floodplain Ordinance used early in the development process, and they should require or at least encourage development to avoid flood-prone areas. Planning and zoning regulations should allow only those land uses that are compatible with the natural conditions of the land. For example, in areas where there is no infrastructure for sanitary sewers, the regulations should specify a lot size large enough for the soil type to accommodate the drain field needed for a septic system. Use of the land should be tailored to match the land’s hazards, such as reserving flood- prone areas for parks, greenways, golf courses, backyards, wildlife refuges, wetlands, natural areas, resource conservation areas, or similar compatible uses. Planning and zoning regulations should allow developers flexibility to arrange improvements on a parcel of land so they can reach their development objectives and avoid the hazardous areas at the same time. One way to do this is through the planned unit development (PUD) approach discussed on page 4-10. Plans Most communities use comprehensive plans or land use plans to guide future development. Although it usually has limited authority, the plan sets out what the community would like to see happen. It guides other local measures, such as capital improvement programs, zoning ordinances, and subdivision regulations. Plans can reduce future property damage by specifying land uses of open space or low density development within areas known to be flood-prone. Unfortunately, flooding or other natural hazards are not always considered when many communities prepare their plans. But in more and more instances, community plans call for reserving flood- prone areas as open space. One example is St. Charles, Illinois (see facing page). A capital improvement plan will guide a community’s major public expenditures for 5 to 20 years. Capital expenditures may include flood control projects and drainage modifications; acquisition of open space in flood problem areas; and extension (or withholding) of sewers, water lines, and other public services into flood-prone areas. Zoning A zoning ordinance regulates development by dividing a community into zones or districts and setting development criteria for each zone or district. Zoning is the primary tool for implementing a comprehensive plan’s guidelines for how land should be developed. Zoning ordinances can limit development in flood-prone areas, such as reserving the SFHA for agricultural uses. A zoning ordinance can also require larger lots or lower densities in areas with flooding, poor soils, or known drainage problems. This requirement helps to ensure that the builder can locate a suitable place on the lot for the structure and reduces the total number of people who will be exposed to the hazard. On large lots, a lower percentage of the area will have impervious surfaces, and it will be easier to preserve natural storage depressions. As a rule of thumb… wetlands, floodplains, and slopes… take first priority for inclusion in the designated open space, as they represent highly sensitive environmental resources that are generally considered to be unbuildable in a legal sense, in a practical sense, or for reasons of common sense. Arendt (1996) St. Charles’ Comprehensive Plan The Comprehensive Plan of the City of St. Charles, Illinois, was adopted in 1996. Three chapters are devoted to natural development factors: geological conditions, hydrological conditions, and open space. The introduction to this section states: Many of today’s environmental problems result either from past ignorance of the impact of man’s actions or insufficient attention to the importance of natural systems…. An understanding of this information will enable the community to build and maintain a harmony between development and nature. Comprehensive Plan, page 5-2. The plan recommends that permit applications be required to include a soil survey and development proposals be reviewed by the Soil and Water Conservation District for their impact on natural features. The chapter on hydrological conditions notes that “One of the best ways to prevent losses from flood damage is to protect floodplains from development” (page 6-6). It then describes the beneficial uses of floodplains, such as outdoor recreation, wildlife habitat, and scenic beauty enhancement. This chapter includes a map showing all the lots and floodplains in the city. The chapter on open space and recreation builds on this goal to preserve floodplains. It identifies the benefits of preserving and restoring natural areas and the special attention that should be paid to the Fox River waterfront. There is also a section on continuity of open space, which recommends corridors to protect linear features (like streams) and to link parks and other sites. Pursuing these concerns not only makes for a more pleasant and safe environment to live in, it also enhances the city’s image and character. All of these concerns come together in one of the most important parts of the Plan, the Future Land Use Map. As seen in the excerpt below, the city intends to overlap the green open space areas with the blue watercourses and their floodplains. An increasing number of communities have adopted the PUD approach. The PUD approach allows adjustment of site design standards and land use densities to preserve open space and/or flood-prone areas from development. In return, the developer is allowed to have a higher density in the flood-free area (see example on facing page). Standards for Subdivisions Although land use plans and zoning ordinances can help steer development away from flood-prone areas, some development inevitably will occur in those places. This guide recommends that communities use two types of regulations for such development: (1) ensure that the infrastructure is free from flood damage and does not aggravate flooding, and (2) ensure that individual buildings are protected from flood damage. “Infrastructure” is a term that encompasses the public works and utilities that serve development. These include the streets, water lines, drainage system, storm and sanitary sewers, and subdivision layout. The standards recommended here usually would be incorporated into the community’s subdivision regulations. Four provisions of subdivision regulations are reviewed in this section: Designing subdivision layouts to keep infrastructure and buildings out of flood problem areas; Setting buildings back from the source of flooding through buffers; Controlling stormwater runoff; and Incorporating the “green infrastructure” approach. Subdivision Layout Zoning ordinances dictate the density of development in each zoning category (for example, a zone of R2 may require a minimum lot size of 0.5 acre). Typically, a developer will divide the parcel evenly, so that a 10-acre parcel will have 20 evenly spaced half-acre lots. The concept of PUD is illustrated on the following page. Subdivision developers should always be encouraged to vary from the traditional approaches if by doing so they can avoid building in the flood-prone areas. Cluster development is an attractive redevelopment option for developers because the cost of land clearance, site preparation, and infrastructure is reduced. Sometimes, the community will allow higher densities than permitted under the regular zoning district as an incentive to keep new construction out of flood-prone areas. In Activities 420 and 430LD (Open Space Preservation and Land Development Criteria), the CRS encourages and provides credit for: Regulations that preserve floodplains as open space; Regulations that encourage developers to set aside floodplains from development; and Floodplains zoned for lower density development (less than one building per acre). Buffers If the subdivision layout does not keep entire lots out of the flood-prone area, buffers can help minimize the amount of development exposed to flooding. Buffers require certain areas to be kept open and free of development. A buffer is typically a setback of a specific distance, such as 25 or 100 feet, from a channel, floodway, wetland, or other water feature. In that area, no cutting, clearing of ground cover, or alteration of the natural features is allowed, but the rest of the lot can be regraded and built on. In the State of Maryland, for example, a 25-foot buffer is required next to all wetlands. Under such a restriction, buffers help: Preserve the natural habitat adjacent to the water; Improve the visual appearance of the waterway; Reduce the potential for disruption or erosion of channel banks; and Filter runoff to the stream, improving water quality. Buffers are also a best management practice (BMP) recognized under the National Pollutant Discharge Elimination System (NPDES). For further information on NPDES, see page 8-5. PUD: In the standard zoning approach (left), the developer considers six equally-sized lots without regard for the flood hazard. Two properties are subject to flooding and the natural stream is disrupted. On the right is an alternative, flexible, PUD approach. The floodplain is dedicated as public open space. There are seven smaller lots, but those abutting the floodplain have the advantage of being adjacent to a larger open area. Four lots have riverfront views instead of two. These amenities compensate for the smaller lot sizes, so the parcels are valued the same. The developer makes the same or more income, and the future residents are safer. Lake County, Illinois, Stormwater Management Commission Buffers protect natural areas and filter runoff into streams and ponds. They have a spin-off benefit of keeping buildings away from sources of floodwater. Buffers Help Manage Stormwater and Protect Wetlands The south suburbs of the Chicago area are subject to several types of flood problems. The South Suburban Mayors and Managers Association initiated a South Suburban Stormwater Strategy to develop programs to reduce the area’s exposure to localized flooding. One of the resulting projects was a model ordinance that combined floodplain management, stormwater management, and wetlands protection measures. Section 11 of the Model Stormwater and Floodplain Management Ordinance of the South Suburban Mayors and Managers Association has the following buffer language: 11.1. Buffer Areas Required. Buffer areas shall be required along all streams, lakes, waterways, channels and wetlands, except for the following: (a) Roadside ditches; (b) Existing excavated stormwater storage facilities; (c) Borrow pits and quarries; (d) Leveed waterways; and (e) Improvements to existing public roads and utilities. 11.2. Buffer Area Dimensions 11.2.1. Linear Buffers. Linear buffers shall be designated along both sides of all streams and natural channels. A minimum buffer of thirty feet on each side of the channel shall be provided. 11.2.2. Water Body Buffers. Water body buffers shall encompass all lakes, wetlands and other non-linear bodies of water. A minimum buffer of thirty feet on each side of the channel shall be provided. 11.2.3. Exceptional functional value wetlands shall have a minimum buffer of one hundred (100) feet. 11.2.4. In areas having State or Federal threatened and endangered species present or for Illinois Natural Area Inventory Sites, buffer widths may be modified to meet the terms and conditions specified during consultation with the Illinois Department of Natural Resources (DNR) or United States Fish and Wildlife Service, pursuant to State and Federal laws and regulations. 11.2.5. The buffer area for all Waters of the United States shall extend from the ordinary high water mark. The buffer area for wetlands shall extend from the edge of the delineated wetland. A property may contain a buffer area that originates from the Waters of the United States on another property. 11.2.6. Buffer averaging may be allowed by the [title of permit official], provided the buffer width is at least half of the buffer width required by this ordinance or the minimum width required by a Corps of Engineers permit, whichever is wider. 11.3. Buffer Requirements 11.3.1. Features of the stormwater management system may be within the buffer area of a development. 11.3.2. Access through buffer areas shall be provided, when necessary, for maintenance purposes. 11.3.3. Preservation of buffer areas shall be provided by deed or plat restriction. 11.4. Allowed Uses in Buffer Areas 11.4.1. All buffer areas shall be maintained free from development except for the following uses: (a) Passive recreation, including pedestrian, bicycle, or equestrian trails. (b) Construction and maintenance of utilities and stormwater facilities. 11.4.2. Structures and impervious surfaces related to recreational facilities, such as trails and paths, may occupy a maximum of twenty (20) percent of the buffer surface area, provided the runoff from such facilities is diverted away from the Waters of the United States or such runoff is directed to enter the buffer area as unconcentrated flow. Boat docks, boathouses and piers shall be allowed and count as a structure when calculating percent of impervious area. 11.4.3. Buffer areas hydrologically disturbed by allowing construction or as part of a revegetation plan shall be revegetated using the Native Plant Guide for Streams and Stormwater Facilities in Northeastern Illinois, (NRCS, et al.) as a minimum standard. Example buffer regulations are on the facing page. Enforcing buffer requirements is very important. Although many communities have excellent enforcement programs while construction is taking place, it must be remembered that permanent buffers and easements need to be established and kept open forever. Many property owners are not aware that 10 years after the house has been built, they still cannot build a shed in the easement or chop down trees in the buffer area. Stormwater Management Development activities outside the flood-prone area can significantly affect drainage and flooding. Stormwater runoff is increased when natural ground cover is replaced by urban development. To protect properties from runoff, developers “improve” the local drainage system by putting parts of it underground in storm sewers and building ditches to carry larger surface flows. This combination of increased runoff and drainage system modifications may increase flooding, overload the downstream drainage system, cause erosion, and impair water quality. Today, most communities have stormwater management requirements designed to minimize the adverse impacts caused by urban development. Instead of building larger pipes and ditches to hurry the water away from a development (and onto someone else’s property), subdivision ordinances have standards to manage stormwater. Stormwater management encompasses four objectives: Manage stormwater runoff so new development is not damaged during a major storm; Prevent new development from diverting surface flows onto other properties; Prevent new development from increasing the peak flows to the receiving drainage system; and Maintain or improve the quality of the water in the system. To meet these objectives, a community’s subdivision or other development regulations should have stormwater management standards. These usually include the following: Locate building sites on higher ground or on human-made building pads so stormwater will run away from the building, into swales, or into the street. Design swales along lot lines to carry water to drainage easements, the street, or nearby ditches (see the Orland Hills illustration on page 4-18). Design storm sewers to carry the runoff from smaller storms without causing street flooding. Traditionally, the national standard is for storm sewers to carry the 10-year storm. Recently, communities are finding that older estimates of the 10-year storm understated the true hazard, so they are addressing larger storms. In Activity 450 (Stormwater Management), the CRS encourages and provides credit for regulations that require developers to detain or retain excess stormwater runoff and that require stormwater management facilities to include features that improve water quality. Ensure the infrastructure can handle larger storms without damaging buildings. For example, the streets or a defined overflow path can be designed to handle the runoff that will not fit in the storm sewers, provided that emergency access routes are established and maintained. Design parking lots, rooftops, streets, or storage basins to hold the runoff and release it downstream over time, keeping the peak flow to a level at or below the peak flow that existed under the pre-development conditions. Incorporate water quality provisions in the storage basins. For example, if water is held for a period of time, sediment and other pollutants can settle to the bottom, and the released water will be cleaner than when it entered the basin. These techniques can also help meet the community’s NPDES goals. Increasingly, communities are incorporating existing natural features into their stormwater management plans and including water quality aspects in their drainage system design. There is a move away from storm sewers, which are expensive and have limited capacity, toward open swales and grassy ditches, which can carry larger flows and have the added advantage of filtering and cleaning the water. Green Infrastructure As noted at the beginning of this section, infrastructure is a term that encompasses the public works and utilities that serve development. Typically, streets and drainageways are thought of as essential public features that must be included in all new subdivisions and other developments. The green infrastructure concept views natural areas as another form of infrastructure needed both for the ecological health of an area and for the quality of life that people have come to expect. Many communities have realized that open space and green areas are just as vital to urban development as are water and sewer lines. Green infrastructure can include parks, buffers along waterways, greenways, farms, backyards, residential landscaping, and urban gardens. These areas can have multiple uses. Not only do they protect natural functions and habitat, but they also act as stormwater storage areas, water conveyance areas, and runoff filters. They can be excellent parks, trails, and recreational features that increase the value of the properties near them. Floodplain Regulations Every community in the NFIP has floodplain management regulations. These regulations require that the lowest floor of any new or substantially improved residential building be elevated at or above the BFE. Nonresidential buildings can be elevated or floodproofed. The Maryland Department of Natural Resources is working to identify those undeveloped lands that are most critical to the State’s long-term ecological health. These lands, referred to as Maryland’s green infrastructure, provide the natural foundation needed to support diverse plant and animal populations, and enable valuable natural processes like filtering water and cleaning the air to take place. Identifying and setting priorities for protection of the green infrastructure is an ongoing process. A description of Maryland’s green infrastructure, including county-by-county maps, can be found at http://www.dnr.state.md.us/ greenways/gi/gi.html. Why not enforce these standards in known problem areas that are outside the SFHA designated on the FIRM? The standards work in the official floodplain, and they can be just as effective in other flood-prone areas. The discussion in the beginning of this chapter describes how these other areas can be mapped. The community needs only to adopt the new map as part of its floodplain management ordinance. Stormwater Management in the Butterfield Creek Watershed A study by the Natural Resources Conservation Service in the 1980s concluded that if all development in Illinois’ Butterfield Creek watershed were required to construct storage basins, flood heights and erosion would still increase because of the loss of natural water storage areas. Faced with repetitive floods, streambank erosion, and other problems, the communities in the watershed formed the Butterfield Creek Steering Committee to look at the causes of the problems and possible solutions. It was concluded that the existing open areas in the upper reaches of the watershed must be preserved in order to provide the needed natural stormwater storage. To do this required a great deal of cooperation between the downstream and upstream communities. Working together, the Steering Committee prepared a Vision Plan, sought funding support, and received cooperation and money from a variety of agencies. The Vision has regulatory measures, corrective actions, and a strong recreational element. A key part is a master floodplain and stormwater management model ordinance that all the communities adopted. Developers are encouraged to preserve marshes and wetlands for their flood storage capacity and to enhance wildlife habitat and recreational opportunities. Other storage areas have been purchased and turned over to park and forest preserve districts. A typical floodplain management ordinance includes the sections listed below. The appropriate amendments are shown in red. Additional studies for other areas can also be referenced. Note that any revision of the ordinance should be made only after reviewing the change with the State or the FEMA Regional Office to ensure that it complies with the NFIP. Section __. Lands to which this ordinance applies This ordinance shall apply to all the special flood hazard areas (SFHAs) as shown on the Flood Insurance Rate Map of the City of Floodville. The SFHA shall also include the regulatory floodplain along Oliver Creek as shown on the Oliver Creek Flood Study. Section ___. Basis for establishing the areas of special flood hazard The SFHAs are identified (1) by FEMA in the Flood Insurance Study for the City of Floodville, dated January 1, 1995, and (2) by the Oliver Creek Flood Study conducted by Lightning Engineers, dated June 23, 2004, with accompanying maps and other supporting data adopted by reference and declared to be a part of this ordinance. Other sections of the floodplain management ordinance adopt the regulatory BFE and floodway. Those sections would be similarly amended. If the new area to be regulated has not been delineated by a detailed study and there is no calculated BFE, other techniques can be used to set a regulatory flood elevation, as described earlier in this chapter. One key factor in the NFIP floodplain management regulations is that they cover existing buildings as well as new ones. If an existing building in the SFHA is to undergo a substantial improvement (i.e., the cost of the improvement or addition equals or exceeds 50 percent of the value of the building), then the building must be brought into compliance with the floodplain management regulations. If the building is damaged (by any cause) so that the cost to repair the structure to its pre-damaged condition exceeds 50 percent of the value of the building, then it is considered to be substantially damaged. As with a substantial improvement, a substantially damaged building must be brought into compliance with the floodplain management ordinance. There is a special funding provision in the NFIP for insured buildings that have been substantially or repetitively damaged by a flood. Increased Cost of Compliance (ICC) coverage provides for the payment of additional funds (up to $30,000) to help pay for the cost to comply with community floodplain management ordinances after a flood in which a building has been declared substantially damaged or repetitively damaged. A community that is serious about reducing its repetitive localized flooding problems would benefit by learning the details of ICC coverage. ICC currently is available to properties in the SFHA. After regulations pursuant to the Flood Insurance Reform Act of 2004 are published, there will be ways for properties outside the SFHA to benefit from this provision, too. The community should discuss ordinance language with the FEMA Regional Office. Proper enforcement and an informed property owner can greatly facilitate the claims process and help provide funding to mitigate the risk to the flood-prone building. Site Drainage Inadequate site drainage is a common cause of flood damage to buildings. Conveyance of stormwater away from a structure is critical to prevent overland flooding of the structure. It can also help prevent basement flooding due to high groundwater elevations. Three regulatory approaches can prevent future problems caused by inadequate site drainage: Require new subdivisions to account for drainage from each lot; Require individual buildings to be elevated; and Enforce drainage easement provisions. Subdivision Design When a subdivision is designed, a separate drainage plan should be prepared and reviewed by the community’s engineers. It should include the stormwater management provisions discussed above to ensure that excess surface flows are properly handled. A subdivision or other development proposal may also include a separate drainage or grading plan. Individual lots should be designed to direct the flow of surface water away from the building. Typically, the developer must provide a building pad on each lot. The top of the pad must be at a certain elevation or a set number of feet higher than the edge of the lot. Most subdivision regulations require utility or drainage easements to be set aside as part of the subdivision plat. Such easements are 5 or 10 feet inside the property line and carry restrictions that prohibit construction or obstructions. Stormwater flows from the building pad to the easements and into the street or a drainageway. An example of a properly designed drainage pattern is shown on the left side of the illustration on the following page. Building Elevation Some homes have been built at grade. In very flat areas, the first floor may be only a few inches higher than the ground. When it rains, the water does not drain away. Instead, it ponds or flows into these low structures. This has been a significant cause of repetitive flooding problems, especially in the South where, over the last 50 years, slab-on-grade foundations replaced the earlier method of building houses on piers or crawlspaces. Under the old construction method, localized floodwaters flowed under the first floor, causing no damage. With the more recent construction techniques, such flooding goes over the slab and into the first floor (see the left side of the St. Tammany Parish example on the facing page). There are three typical approaches to ensure that new buildings are not built too low for the circumstances: Require positive drainage away from the building. This is a standard provision in the model building codes. Section 1803.3 of the International Building Code has such a requirement, for example, so this provision may The Village of Orland Hills, Illinois, found out the hard way why it is important to keep drainage easements open. Some of the problems that occurred are described in the sidebar on Orland Hills in Chapter 2. This graphic is based on the Village’s 1995 Flood Protection Plan that explained the problem to the public and helped launch more public information and enforcement activities to keep the easements open. The number of violations and drainage complaints has steadily decreased over the years since the Plan has been implemented. already be part of the community’s regulations, but that does not mean that it is always adequately enforced. Require the lowest floor of new buildings to be 1 or 2 feet higher than street level (see the right side of the St. Tammany Parish example above). Require the permit applicant to submit a site plan that accounts for local drainage from and onto adjoining properties and that protects the building and adjoining properties from local drainage flows. Drainage Easements Most lots have utility or drainage easements that set aside the area that is 5 or 10 feet inside the property lines. These easements are designed to carry surface water away from the buildings and to the street, storm sewer, or other drainage facility (see illustration of drainage patterns on facing page). Easements must be kept open to do their jobs. Unfortunately, many property owners do not realize (or forget) that the easements exist or why they are needed. When people build fences, garages, sheds, or swimming pools, or plant trees in the easement, the drainage pattern is disrupted and surface water will be pushed onto other properties. The photograph on the following page shows how a local drainage system can become obstructed when property owners forget to keep their easements open. French & Associates St. Tammany Parish, Louisiana St. Tammany Parish, Louisiana, had many homes built close to grade in very flat areas. Heavy rains caused on-site flooding and did not drain away quickly. Homes like the one on the left were frequently flooded. In response, the Parish adopted a requirement that lowest floors be at least 6 inches above the street. Site plans for new construction combine elevation of the building pad with improved drainage, so local drainage is not a flooding problem in new subdivisions (as shown on the right). In Activity 450 (Stormwater Management), the CRS provides credit for all three approaches to protect new buildings from local drainage problems. For easements to work, the easement restrictions must be enforced by the community. Property owners must be reminded to obtain permits for sheds, swimming pools, fences, and other structures that can alter the ground surface. Permit officials need to check the easements before issuing a permit and conduct on-site inspections for all projects, no matter how small, to ensure that they do not encroach on the easements. A public information program can be an effective tool to help enforce these regulations. Property owners who are aware of and understand the need for keeping easements open are less likely to obstruct them and are more likely to advise local officials when they see potential problems. As noted on page 2-6, Orland Hills used a combination of regulations, public information, and drainage modifications to reduce its drainage problems. Where to Get Help The following agencies can help with mapping regulatory floodplains: FEMA U.S. Army Corps of Engineers Natural Resources Conservation Service State Department of Natural Resources The following agencies can provide assistance in reviewing the community’s regulatory standards and setting new ones: FEMA State National Flood Insurance Program Coordinator Training and references on these topics can be found through: FEMA Association of State Floodplain Managers State and regional associations of floodplain managers American Society of Civil Engineers Additional resources are listed in Appendixes A and B. French & Associates When this subdivision was constructed, the backyards were open. Over the years, fences along the lot lines have disrupted the drainage system. Stormwater would flow away faster if these obstructions were removed. Reducing Damage from Localized Flooding: A Guide for Communities 5-1 5 Public Information and Awareness One of the most effective long-term ways a community can cope with localized flood problems and prevent future ones from occurring is by educating its residents about why such problems occur outside the Special Flood Hazard Area (SFHA) and what they can do to help prevent them. A community can choose from numerous avenues to build awareness of and knowledge about localized flooding and remedies. The following public information activities serve community residents, property owners, insurance agents, lenders, and real estate agents by advising them about the flood hazard, flood insurance, ways to prevent or reduce flood damage to buildings, and the natural benefits and functions of floodplains. Answer Questions Virtually all communities provide residents with information about flooding and preventive measures if they ask for it, perhaps when they inquire whether a property is in the floodplain or they request an elevation certificate. National Flood Insurance Program (NFIP) communities are required to make public documents available, such as the current Flood Insurance Rate Map (FIRM), or permit records, so that residents can consult them as needed. Communities with drainage problems or other types of localized flooding should be ready to explain that the issue is more complicated than simply being inside or outside the SFHA, or 100-year floodplain. The community’s program for providing map information could be expanded to offer information about low-risk areas as well as about the 100-year flood. Local staff should provide information about all known flood hazards, including those not mapped on the FIRM. The local staff should be prepared to provide information and advice about: Safety measures that can be taken by individuals, property owners, drivers, and passengers in automobiles; Flood risk both inside and outside the SFHA; Chapter 5. Public Information and Awareness PART II Reducing Damage from Localized Flooding: A Guide for Communities 5-2 Retrofitting techniques to make buildings safer; Building techniques and standards (or regulations, if applicable) to make a new structure resistant to shallow flooding (such as placing utilities above the flood level); Sources of help in taking action to reduce flood damage; The availability of flood insurance and insurance for sump pump failure and sewer backup, even outside the floodplain; and Special flood-related problems in the community, such as streambank erosion or subsidence. A community’s technical staff—building department personnel, code enforcement officers, public works staff—have expertise and experience in construction. Although they cannot assume responsibility for the design or construction of a property owner’s project, they can answer inquiries about flood protection measures, point people in the right direction, explain what won’t work, and identify licensed companies or experienced contractors who can do the work. Some building department or public works staff, such as those of the St. Louis, Missouri, Metropolitan Sewer District, visit properties on site and offer suggestions. French & Associates Before a permit is issued, permit officials should review all information known about drainage and local flooding problems in the area. Credit is provided by the CRS under Activity 360 (Flood Protection Assistance) for visiting a problem site and giving the property owner advice appropriate for the situation, such as retrofitting techniques and names of qualified contractors. Chapter 5. Public Information and Awareness PART II Provide Resources for the Public People who set out to learn more about localized flooding and its possible remedies are far more likely to follow through if they find resources within the community that help them with their mission. A community can help by making sure that various types of information about local flooding are accessible to the public. The local library is a logical place to start. A community could have a special section in the library that includes materials on its local flooding history, flood control and drainage projects, success stories, guidance for homeowners, flood maps, and natural resources associated with the streams, such as wetlands or wildlife habitat. Interested property owners can read or check out handbooks or other publications that apply to their situations or log on to the Internet to search for helpful Web sites. Some communities participating in the Community Rating System (CRS) already have documents on flood risk available in the library, and get CRS credit points for doing so. It would be simple to augment this collection with specific information about local flooding within the community, action to take, and experts to contact for advice. A community can display its maps showing flood risks at various places in town—the city hall, public works offices, library, or other visible locations. If additional information (beyond what is displayed on the community’s FIRM) is shown on these maps, the residents are more likely to become interested in flooding problems and remedies. The maps should show not only the 100-year floodplain but also other features relevant to local flooding, such as low-risk flood areas, drainage problems, natural zones along waterways, or wetlands. They could incorporate aerial photographs that show recognizable buildings or landmarks, information about additional hazards (such as landslides); flooding outside the SFHA; natural habitat and parks; or zoning and development regulations. Not only can the community Web site be a research tool, but it also can be a quick way to stimulate interest or convey ideas to Internet surfers. The Web site could include the same sorts of information housed in the local library, but with the advantage of being displayed in a more attention-getting format. It is not difficult to provide links on the community’s Web site to many different sources of information, both public and private, about floods, flood insurance, property protection, and other ways of coping with local flooding. Mecklenburg County, North Carolina, has an interactive Web site that allows people to look up their flood zones, as well as obtain educational information (http://maps.co.mecklenburg.nc.us). The Colorad