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Home , East Lake Tohopekaliga, Loxahatchee River, Rainbow River, Swale (landform), Waccasassa River

MANAGEMENT A GUIDE FOR FLORIDIANS

Florida Department of Environmental Regulation

Stormwater/Nonpoint Source Management 2600 Blair Stone Road Tallahassee, 32399-2400

Lawton Chiles, Governor Virginia B. Wetherell, Secretary

prepared by:

Eric H. Livingston Environmental Administrator

Ellen McCarron Environmental Specialist

funded by:

U.S. Environmental Protection Agency

The preparation and publication of this booklet was funded Cover Photograph: DER’s Commitment to stormwater in part by a grant from the U.S. Environmental Protection management is demonstrated by its Agency through the Nonpoint Source Management Program new wet detention system which replaced a traditional drainage system. pursuant to Section 319 of the Federal . CONTENTS STORMWATER MANAGEMENT: A GUIDE FOR FLORIDIANS

INTRODUCTION ...... 5 E. Detention Practices ...... 47 ONE - BACKGROUND ...... 7 F. Stormwater Systems ...... 53 G. Detention with Filtration ...... 54 A. Hydrological Cycle ...... 7 H. Parking Lots ...... 55 B. The Watershed ...... 8 I. Alum Treatment ...... 57 C. The River (Lake) System ...... 9 J. Maintenance of Stormwater System ...... 59 D. The Estuarine System ...... 9 E. The Groundwater System ...... 11 SIX - STORMWATER REGULATORY PROGRAMS ..61 F. The Groundwater-Surface Water-Land A. Federal NPDES Stormwater Permitting ...... 61 Connection ...... 13 B. State Stormwater Permitting ...... 62 TWO - THE STORMWATER PROBLEM ...... 15 C. Local Government Stormwater Permitting ...... 63 A. Effects of Urbanization on Stormwater Quantity ... 16 SEVEN - WHAT LOCAL GOVERNMENTS CAN DO .65 B. Effects of Urbanization on Stormwater Quality ..... 17 A. Develop a Watershed Management Plan ...... 65 C. The First Flush ...... 19 B. Implementation of the Watershed Plan ...... 66 Local Ordinance ...... 66 THREE - STORMWATER AND WATERSHED Public Education ...... 66 MANAGEMENT ...... 21 Funding - Stormwater Utilities ...... 68 A. Stormwater Management ...... 21 C. Operation and Maintenance of the Stormwater B. Watershed Management: The Challenge of the System...... 70 Future ...... 22 D. Intergovernmental Coordination ...... 70 FOUR - PRINCIPLES OF STORMWATER CONCLUSION ...... 71 MANAGEMENT ...... 29 INFORMATION SOURCES ...... 72 FIVE - STORMWATER MANAGEMENT PRACTICES .. 33 ACKNOWLEDGEMENTS ...... 72 A. BMP Treatment Train ...... 34 B. On-Line vs. Off-Line BMP’s ...... 35 C. The Importance of Vegetation ...... 37 D. (Retention) Practices...... 38 Dry Retention Basins or Areas ...... 39 Grassed Swales ...... 41 Infiltration Trenches ...... 44 4 4 INTRODUCTION Water flowing over the land during and immedi- culverts, storm sewers and navigable waters to ately following a rainstorm is called stormwater restore their capacity. In addition to sediments, runoff. stormwater carries nutrients, heavy metals, oils, greases, pathogens and any other materials that Stormwater runoff from agricultural lands, from accumulate on the land between rains. lands that are undergoing urban development and from lands which already are developed This guidebook has been prepared as a source causes significant problems for landowners in its of general information on urban stormwater path, for local governments, and for the water- management. It is intended for the fuse of local bodies which ultimately receive it. government officials and others interested in sound planning and design of stormwater man- As a result of stormwater, sediment fills drainage agement systems. It presents general information ditches and channels, causing flooding. The sedi- on the stormwater problem and how to manage ment fills rivers, lakes and , destroying it. Sound planning and good design can create wildlife habitat, degrading water quality, and re- stormwater management systems that are attrac- quiring extensive restoration. High velocity tive, safe, and efficient, and which provide many causes bank erosion (and more sedimentation different uses and benefits to the community. downstream) and loss of valuable habitat and It is much easier, and much less expensive, property. Areas that once seldom flooded now to prevent stormwater problems through flood with regularity. Eroded sites must be proper planning than it is to restore water regarded. Often, new soil must be brought in to bodies and rebuild flooded properties. replace the soil which has washed away. Sediment must be removed – at great cost – from

5 6 CHAPTER ONE BACKGROUND THE IMPORTANCE OF WATER

Water is Florida’s lifeblood. Whether it is used for the , lakes and rivers that eventually flow agriculture, industry, recreation, or for drinking, an to the sea; it can infiltrate through the soil, re- abundance of clean water is essential for Florida’s charging the ground water, or it may be absorbed economy and our quality of life. Florida’s rapid into the topsoil to be used by plants and eventu- growth, and the vulnerability of its surface and ally returned to the atmosphere through evapo- ground waters, makes it imperative that its water transpiration, which is the evaporation of water resources are managed wisely. Fortunately, the from land surfaces plus transpiration, the water Sunshine State receives and abundance of rainfall- given off by the roots and leaves of plants. – 50 to 65 inches from about 120 storms a year. The resulting stormwater, just like treated waste- Of course, this is a simplified explanation of a water, represents a valuable component of our very complex natural system – a system that in water resources to be recovered and reused. undeveloped areas maintains a dynamic balance. Natural stormwater systems are in constant A. The Hydrologic Cycle change: change course, natural erosion occurs, and vegetation and soil permeability In undeveloped areas, stormwater management change with the seasons. the natural system is is part of the natural environment. The movement thrown out of balance by man-made changes to of water through the environment, from the the land. clouds to the earth, and back again, is called the Hydrologic Cycle (Figure 1). The effect of water moving through Florida’s di- verse water system can differ greatly depending The cycle begins with the sun’s energy warming on whether the receiving water is a river, lake, surface waters, causing evaporation. It continues or ground water system. Additionally, when water vapor rises into the atmosphere, con- Florida’s water systems often are intercon- denses to form clouds, then falls to earth as rain nected—surface waters become ground waters or snow. which can eventually flow back to surface water. A brief discussion of Florida’s various water sys- When water reaches the ground, it can take three tems follows to provide a basic introduction to main paths: it can run off the land and collect in these complex, interrelated systems.

7 B. The Watershed A watershed (or ) is the geographic water resources of that watershed. It is for this dination and cooperation among local and area from which water in a particular stream, lake reason that we must begin to manage our land and regional governments, state government and the or estuary originates (Figure 2). All lands in the water resources in a comprehensive, coor- private sector is essential for effective water watershed drain toward the stream, lake or bay dinated manner through Watershed Manage- management. If one community limits pollutants and contribute pollutants to these waters. It is ment. Watershed management is the integration or manages its stormwater but others within the important to recognize the connection between of land use, infrastructure and water resources watershed do not, then flooding and water our activities on the land within a watershed and throughout an entire watershed. quality problems can still result. Those who join the ground water and surface water that flows the Watershed Management Team can work through it. Everything we do on the land within the Watershed boundaries rarely correspond to local together and effectively solve problems and mange watershed ultimately will have an effect on the government boundaries. As a result, coor- the resources within a watershed.

8 C. The River (Lake) System The characteristics of water and its effects on daily within the same watershed, and so can affect one behind barrier islands like Apalachicola Bay and life can be best understood by studying the river another through their various uses of land and Santa Rosa Sound. All of these estuaries have or lake basin in which a community is located. water. different salinity patterns, tides, marine life, sedi- ment types and shorelines. The conditions within For instance, a small creek running through a D. The Estuarine System estuaries are continually changing so the organ- neighborhood may appear to be unrelated to the Coastal estuaries have been called the cradle of isms that live in them must be adaptable. The stream that crosses another part of town, but life. They are the bodies of water where fresh combination of changing salinity, temperatures, they can be connected. Creeks join to create and salty water mix, producing a nutrient-rich and tides, together with shallow water and march larger streams, which in turn form still larger ones habitat for plants, animals and fish. Florida’s grasses, provides physical protection and abun- in a natural drainage network that carries rain- estuarine system, the largest in the United States, dant food for juvenile fish and shellfish that use water off backyards, fields, and streets and into encompasses three million acres of tidal streams, estuaries as nursery areas. rivers or lakes or estuaries. Without this natural wetlands, bays and lagoons. Estuaries are one of stormwater system, land would stay wet or the most productive natural systems on earth. In The very functions that make estuaries productive flooded. Florida, they account for more than seventy per- also make them vulnerable to pollutants in stormwater. Just as estuaries efficiently trap and As water circulates through a river system it can cent of the recreational and important commer- cial fish and shellfish. recycle the nutrients that support the estuarine carry pollutants to downstream parts of the food web, they can also trap and concentrate watershed. This is why lakefront or coastal resi- Florida has a wide variety of estuaries, ranging pollutants. Estuaries can be hurt by too much dents may be concerned about the activities from tidal rivers like the St. Johns River, secluded fresh water, the possible result of urbanization of people living some distance upstream from lagoons like the lagoon, tropical bays and the increase in stormwater runoff in the them. Although many miles apart, they all live like Florida and Biscayne Bays, and shallow basins estuarine watershed.

9 10 E. The Ground Water System When water seeps into the ground it is either The water in this aquifer moves through the The permeability of soil overlaying an aquifer absorbed by the plants and soil or passes earth under pressure rather than simply by can also affect pollution. For example, the sit- through the soil to become part of the ground gravity. Recharge to the confined aquifer takes ing of septic tanks or retention in areas water supply. More than 90% of Florida’s resi- place only in certain areas (recharge zones), so where the water table lies just below very dents depend on ground water for their drinking it is less likely to get polluted, unless pollution sandy soil can create problems. The porous water. The sand, gravel and rocks that allow sources are located in the recharge zones. sand does not retain pollutants as long as water to collect and move through them are other soils do and it lacks the organic mate- called aquifers. The dynamics of ground water movement are complicated. In essence, ground water moves rial and microbes that can trap and degrade The water level in an unconfined or “water downward, following the slope of the water some pollutants. Areas of Florida with karst table” aquifer will rise and fall depending upon table (not the land surface) from its highest geology-land with numerous sinkholes and the amount of water stored in the ground. The level to its lowest. The water slowly filters be- with underground flow through large cavities recharge of this aquifer occurs by seepage tween the rocks and soil of an aquifer, usually in the limestone-are also highly susceptible to through porous soils when it rains. Although at a rate of a few inches a day. This slow ground water contamination, even from storm- this type of aquifer will recharge relatively eas- movement keeps pollutants from being quickly water management systems. ily, pollutants can seep into it just as easily. diluted. Therefore, a well located down-slope from a source of pollution could be contami- A second type of aquifer is called a confined nated by the ground water flow that still con- aquifer. It consists of layers of various types of tains concentrated pollutants. rock (generally limestone in Florida) and clay.

11 12 F. The Ground Water-Surface Water-Land Connection To maintain the quality of our lakes, rivers and aquifer, some pollutants still reach surface water into the underlying aquifer. An example of this is estuaries, we must recognize the connection be- bodies. Movement of contaminated surface wa- salt water intrusion such as has occurred in Dade tween ground waters and surface waters. In many ter ground water can also occur by percola- County where uncontrolled canal drainage cases, ground water eventually flows into a tion of pollutants from surface impoundments caused declines in fresh water levels allowing river, lake or estuary (Figure 3) or even becomes (e.g., pits, ponds, lagoons) into the aquifer salt water to gradually migrate inland. surface water such as a spring. Although some underneath. not only can ground water contami- of the pollutants in degraded ground water may nation affect lakes, rivers and estuaries but it is be dispersed as the water flows through the also possible for estuarine waters to flow back

Little River Springs creates a stream which fl ows into the and on to the Gulf.

13 14 CHAPTER TWO THE STORMWATER PROBLEM

The volume of stormwater generated by a rain teristics of runoff, changes in runoff volume, storm depends upon the total amount of rainfall, changes in water quality, and changes in the except that lost by infiltration, transpiration, hydrologic amenities. The hydrologic amenities evaporation, and surface storage. The amount of are what might be called the appearance or the these losses is a function of climate, soils, geol- impression a water body and its adjacent lands ogy, topography, vegetative cover and, most leave with the observer. Of all the land use importantly, land use. changes that affect an area’s hydrology, urbaniza- tion is the most important. Changes in land use affect the hydrology of an area in four ways: changes in peak flow charac-

15 A. Effects of Urbanization on Stormwater Quantity As an area urbanizes, streets, sidewalks, park- ing lots and buildings cover the soil. In addition, the process removes natural vegetation and compacts the soil. The land’s surface becomes more impervious. Rainfall no longer soaks into the ground as readily as before. This causes an increase in runoff and accelerates the speed at which runoff flows (the peak discharge rate) as see in Figure 4. Historically, the primary concern about storm- water was to remove it from a developed area as quickly as possible after a storm for flood protection. Unfortunately, this led to drainage systems that maximize local convenience and protection, without considering other important factors such as off-site damage from accelerated flow, , or even the loss of a water resource. Other problems include increased channel erosion and flooding, deposition of sediment, flood plain and channel erosion with a resulting loss of property, wildlife habitat and natural vegetation.

16 In an undeveloped area, a natural stream nor- B. Effects of Urbanization on mally adjusts so that its cross section and slope Stormwater Quality are in approximate equilibrium. Increased volumes Land use directly affects water quality. In an un- Heavy metals (lead, cadmium, chromium, and peak discharge rates of stormwater produce developed area, natural, physical, chemical, and copper, zinc) which can disrupt the reproduc drastic changes in the natural stream channel. biological processes interact to recycle most of the tion of fish and shellfish and accumulate in Eroded banks and frequent flooding are not only materials found in stormwater. As human land use fish tissues. unsightly but cause damage to adjacent property intensifies, these processes are disrupted and ev- and homes. Structures are undermined, homes eryday activities add materials to the land surface. Petroleum hydrocarbons (oils, greases) are damaged, recreational areas are threatened and Leaves, litter, animal wastes, oil, greases, heavy which are toxic to many aquatic organisms. aesthetic values are destroyed. metals, fertilizers, and pesticides are washed off Accelerated channel erosion also creates down- by rainfall and are carried by stormwater to our Coliform bacteria and viruses which con- stream damages by the deposition of eroded lakes, rivers, and bays. These materials can create taminate lakes and shellfish waters and prevent sediment. Lakes and reservoirs fill, storm sewers high pollutant loadings of: swimming and harvesting. and culverts become clogged causing flooding and areas adjacent to streams and lakes may be- Sediment which clogs waterways, smothers Excessive fresh water which changes the come covered with mud and debris left after the bottom living aquatic organisms and increases salinity of estuaries, alters the types of organ flood. turbidity. isms which live in estuaries, and disrupts this important nursery area. Increased stream volumes and velocities associ- Oxygen demanding substrates which con- ated with the stormwater from urbanized areas sume the oxygen in water, sometimes creating Stormwater is the major source of pollutants to produce more frequent floods. Areas that pre- an oxygen deficit that leads to fish kills. Florida’s lakes, estuaries and streams. Improved viously flooded only once every five years may Nutrients (nitrogen, phosphorus) which stormwater management will reduce pollution flood every year, or several times each year. cause unwanted and uncontrolled growth loads from new developments and from old Flood plain erosion and damage to structures and of algae and aquatic weeds like hydrilla or stormwater systems that were built primarily for vegetation increase. hyacinths. drainage.

17 18 C The First Flush Of primary importance to minimizing the effects of Treatment of the first flush is the key to proper size of the drainage basis, the amount of impervi- stormwater on water quality is the FIRST FLUSH stormwater management, and treatment of the ous surface, the type of land use, the type of (Figure 5). This term describes the washing action first one inch of runoff from new development is stormwater management system and, most impor- that stormwater has on accumulated pollutants in the minimum needed to achieve the desired water tantly, the type of receiving water and the desired a watershed. In the early stages of runoff the land quality benefits. In some cases, more than the water quality. surfaces, especially the impervious surfaces like first inch may need treatment-depending on the streets and parking areas, are flushed clean by the stormwater. This creates a shock loading of pol- lutants. Studies in Florida have determined that the first one inch of runoff generally carries 90% of the pollution from a storm.

19 Best Management Practices must be applied throughout a watershed.

20 CHAPTER THREE STORMWATER AND WATERSHED MANAGEMENT A. Stormwater Management Stormwater must be managed to abate the alter- information on how a stormwater manage- ations of the hydrologic cycle caused by changes ment system is designed. In addition, new de- in land use, especially urbanization. An effective velopments must have an erosion and sediment Stormwater Management Program requires control plan using suitable techniques to retain actions to control stormwater to provide: sediment onsite and minimize the tremendous adverse effects that can occur from improperly • Reduction of stormwater pollutants managed construction sites. • Surface drainage and flood protection However, one of the major water quality prob- • Erosion and sedimentation control lems facing Florida is how to reduce the pollution • Enhanced aesthetics and recreational load from old drainage systems that were built opportunities solely for flood protection. These systems had • Reuse of this valuable water resource one purpose: to convey stormwater away from improved properties as quickly as possible. There To achieve these objectives, new developments was little regard for any environmental effects. It (or redevelopment projects) should include a is extremely difficult, and expensive, to correct stormwater management system which assures that problems caused by old systems. The solution the Peak Discharge Rate, Volume, and the will take years. Innovative technology, and close of stormwater leaving a site after Pollution Load coordination with planned infrastructure improve- development are no greater than before develop- ments and urban re-development will be re- ment. Chapters Four and Five present additional quired to solve our stormwater problems.

21 B. Watershed Management: The Challenge of the Future peak runoff and pollution loads from the We must re-evaluate regulatory approaches to development projects; stormwater management to shift the emphasis site at predevelopment levels. There toward more comprehensive, prevention orient- would be little or no consideration of c) providing stream channel improvements (e.g., ed strategies such as “Watershed Planning”. cumulative effects of the developments removal of obstructions to flow, properly Stormwater management is a very important ele- with their individual stormwater systems vegetating) where necessary upstream from ment in watershed planning. on either the local government stormwater the stormwater detention facility; and infrastructure or downstream lands and d) nonstructural measures throughout the water The following comparison illustrates the differ- waters. ences between the usual approach to stormwater shed, such as acquisition of parkland and management and a comprehensive watershed ap- 2) Comprehensive Approach: floodproofing to supplement structural con proach. This option involves developing a compre- trol measures. hensive watershed plan, known as the Watershed management also allows co 1) Usual Approach: “master plan”, to identify the most ordination of infrastructure improvements For existing urban development, the usual appropriate control measures and the with point and nonpoint source manage approach would address local stormwater optimum locations to control watershed- ment programs and provides a vital link problems without evaluating the potential for wide activities. The watershed approach between land use and water resources runoff control measure to cause adverse effects typically involves combinations of the follow management. ing: in downstream areas. In the case of new ur- While the normal approach to urban stormwa- ban development, we would delegate a) overall review of the watershed and its ter management is relatively easy to administer, stormwater management responsibilities characteristics to assess problems and it offers several disadvantages. There is greater to local land developers and each would potential solutions; risk of negative effects, particularly in watersheds be responsible for constructing stormwater b) strategically locating a single stormwater de that cover several jurisdictions. Insignificant flood management facilities on the develop- tention facility (a regional system) to control protection benefits result from emphasis on ment site to maintain post-development post-development runoff from several land the effects of minor flooding. Ineffective runoff

22 control throughout the watershed is caused by • Significant capital and operation/mainte- • Local governments must conduct, in advance, the failure to evaluate locational differences in nance expenditures may be wasted; and studies to locate, and develop preliminary the benefits of stormwater management facilities. • The costs of remedial structural solutions designs for , regional stormwater manage- Relatively high local costs for facility mainte- likely will be much greater than the costs of a ment facilities; nance are incurred, as are unnecessary costs proper management program if it had been associated with the use of small-scale structural implemented in the first place. • Local governments must finance, design, and solutions rather than large-scale non structural construct the regional stormwater manage- solutions which are much cheaper. The watershed master plan approach offers ment facilities before most development significant advantages over the piecemeal occurs and provide for reimbursement by Included among the possible negative effects of approach. It promises reductions in capital developers over a build-out period that can this piecemeal approach to stormwater manage- and operation/maintenance costs and reduc- be many years long. ment are the following: tions in the risk of downstream flooding and • It may only partially solve the major flooding erosion, particularly in multi-jurisdictional water- • In some cases, local governments may have problem(s); sheds. It offers better opportunities to manage to conduct extraordinary maintenance existing stormwater problems and the ability to • It may solve flooding problems in the up- activities for regional stormwater manage- consider nonstructural measures. Other benefits stream jurisdiction, but create flooding prob- ment facilities the public feels are primarily include an increase in land development oppor- lem in downstream jurisdictions; recreation facilities that merit protection tunities, increased opportunities for recreational for water quality. • Randomly located detention basins may in- uses of runoff controls, potential contributions crease downstream peak flows; to local land use planning, enhanced reuse of • The program may result in overall prohibi- stormwater, and popularity among land devel- tively high maintenance costs for significant opers. The major disadvantages of the master number of runoff control facilities; plan approach include.

23 24 C. Florida’s Evolving Watershed Management Table 1 Program Approved Priority List and Plan Of The Surface Water Improvement and Management Program (SWIM) The 1989 STORMWATER LEGISLATION es- July 1, 1991 tablishes a statewide watershed management framework that relies upon a cooperative effort NORTHWEST FLORIDA WMD SOUTHWEST FLORIDA WMD SOUTH FLORIDA continued 1. 1. 14. Corkscrew between the Department of Environmental Regula- 2. Apalachicola Bay/St. George 2. Blue Run () 15. Naples Bay/Gordon River tion, water management districts and local govern- Sound 3. Banana Lake 16. Estero Bay ments. The framework is built upon the integration of 3. Lake Jackson 4. /kings Bay 17. Lake Butler 4. Deerpoint Lake 5. Lake Panasoffkee 18. Alligator Lake the Local Government Comprehensive Planning Act, 5. Pensacola Bay Area 6. Charlotte/placida Harbor 19. Florida Keys the State Comprehensive Plan and the Surface Water 6. St. Marks River 7. Lake Tarpon 20. Pine Island Sound/Matlacha/ Improvement and Management Act (SWIM) into a 7. Choctawhatchee Bay 8. Lake Thonotnsassa Ding Darling 8. 9. Winter Haven Chain of 21. Lake Jackson (Osceola Co.) comprehensive watershed management program (Fig- 9. Santa Rosa Sound Lakes 22. Lake Rosalie ure 6). the framework is set forth in the State Water 10. St. Joseph Bay 23. Cypress Lake (Osceola Co.) Policy, Chapter 17-40, F.A.C. 11. ST. JONHS RIVER WMD 24. Lake Hatchineha 12. St. Andrews Bay 1. Lower St. Jonhs Basin 25. The legislation designates the Department as the 13. Escambia River 2. 26. Lake Worth overall lead agency for the watershed management 14. Lake Munson System 27. Holey Land/ 15. Merritts Mill 3. Basin Rotenberger Tract program with specific responsibilities of establishing 16. Upper / 4. Upper Oklawaha River 28. water quality standards and stormwater treatment Basin 29. Rookery Bay/Marco requirements and of overseeing the program’s imple- 17. Lake Lamonia 5. Basin 30. Lake Pierce 18. 31. Lake Marian mentation by the Water Management Districts and 19. Lake Lafayette SOUTH FLORIDA WMB 32. Lake Trafford local governments. The Districts will be chief admin- 20. River 1. /Kissimmee 33. Corbett Wildlife Management istrators of the state stormwater regulatory program 21. Yellow River River Area 22. Lower Ochlockonee River/ 1. Biscayne Bay 34. Savannas State Reserve and will establish watershed specific goals such as Lake Talquin 1. indian River Logon 35. Three Lake Ranch the allowable stormwater pollutant loading to a 23. 4. / 36. Fish Lake (Osceola Co.) 24. Sand Hill Lakes Florida Bay receiving water. As part of the SWIM Program, 5. Everglades Water Conservation the Districts have identified priority waters (Table SUWANNEE RIVER WMD Area Bold = Approved Plans 1) and are developing watershed management 1. Suwannee River (Withlacoochee 6. River/falling Cr) 7. goals and plans for these waters. 2. System 8. Lake Weohyakapka 3. Costal Rivers Basins 9. Estuary () 10. Big Cypress National Preserve 4. Alligator Lake (Columbia Co.) 11. 5. () 12. Everglades East 6. 13. Lake Arbuckle 25 Local Stormwater Utilities provide dedicated funds for solving stormwater problems and educating citizens.

26 Local governments will play a particularly Development of any comprehensive watershed grating the land use plan, infrastructure plan, and important role in watershed management. management program, whether on a statewide or the capital improvements plan into a watershed Using the watershed goals established by the local basis requires maximum cooperation, and a management plan, communities will provide a water management districts, local governments team approach between all participating agencies, foundation for solving many of their stormwater will need to develop stormwater master plans governments, and private business. Communities and land and water resource problems in a cost- that also are based on their adopted compre- are beginning to shift from the current piecemeal effective manner. hensive plan. The stormwater master plan will to the comprehensive approach. Ultimately the provide a blueprint for the upgrading of the future of Florida’s water resources will depend on existing stormwater infrastructure to reduce the extent to which this leadership is followed. flooding caused by existing and future land The local government comprehensive plans uses and to reduce the stormwater pollutant load are a prime opportunity to develop and discharged to receiving waters as required by implement workable Watershed Management the watershed goals. By implementing a Plans. Much of the information needed for a stormwater utility, a local government will have watershed plan will be developed during the a dedicated source of funds to build the re- comprehensive planning process—watersheds quired stormwater infrastructure. Those funds and soils will be mapped, a future land use plan will also allow a community to implement a will be developed, an analysis of stormwater comprehensive stormwater management pro- systems will be completed, resource manage- gram that includes public education and peri- ment goals will be established, and a capital odic inspection of stormwater systems to assure improvements plan will be developed. By inte- they are maintained properly.

27 Stormwater System creates babbling brook

28 CHAPTER FOUR PRINCIPLES OF STORMWATER MANAGEMENT

The following general principles will help stormwater system which is largely capital, achieve the multiple objectives of stormwater energy, and maintenance cost free. Most management. sites contain natural features which contribute to the management of stormwater under the 1. It is much more efficient and cost-effective to prevent problems than to correct them existing conditions. Depending upon the site features such as natural drainageways, depres- later. Sound land use planning, based on good sions, wetlands, floodplains, highly permeable site planning principles, is essential as the first, soils, and vegetation provide natural infiltra- and perhaps the most important step in manag- tion, help control the velocity of runoff, extend ing stormwater. All new development plans the time of concentration, filter sediments such as subdivisions, shopping centers, indus- and other pollutants, and recycle nutrients. Each trial parks, and office centers and redevelopment development plan should carefully may and iden- plans should include a comprehensive stormwa- tify the existing natural system. “Natural” engi- ter management system. neering techniques should be used as much as 2. Every piece of land is part of a larger possible to preserve and enhance the natural watershed. A stormwater management system features and processes of a site to maximize the for each development project should be based economic and environmental benefit. Natural en- on, and support a plan for the entire drainage gineering is particularly effective when combined basin. with open spaces and recreational use of the site, or in developments that use cluster techniques. 3. Optimum design of the stormwater man- Design should seek to improve the effectiveness agement system should mimic (and use) the of natural systems, rather than to negate, replace, features and functions of the natural or ignore them.

29 4. The volume, rate, timing and pollutant load to increase overland “sheet” flow. These sys- and treatment system, resulting in temporary of stormwater after development should tems increase infiltration and evaporation, upstream flooding. This may lead to hydraulic closely approximate the conditions which allow suspended solids to settle, and help failure of the system, causing resuspension of occurred before development. Two overall remove pollutants before they are intro- pollutants or expensive repairs to dam- concepts must be considered: To the greatest duced to Florida’s waters. aged structures or property. In such circum- extent possible, the perviousness of the site stances it is advisable to use more than one 7. Stormwater management systems, espe- should be maintained, and the rate of runoff outlet or to increase the on-site storage cially those that emphasize the use of should be slowed. Stormwater management volume. vegetation, should be planned constructed systems should use Best Management Practices and stabilized in advance of the facilities (BMPs) that maintain vegetative and porous 9. Whenever possible, construct the compo- that will discharge into them. This principle land cover and which include on-site storage. nents of the stormwater management sys- is frequently ignored, causing unnecessary off-site These systems will promote infiltration, filtering, tem on the contours that follow the natural effects, extra maintenance, reworking of grades, and slowing of the runoff. topography. This will minimize erosion and revegetation of slopes and grassed swales, and stabilization problems caused by excessive 5. Maximize-on-site storage of stormwater. extra expense to the developer. The storm- water velocity. It also will slow the runoff, Provision for storage can reduce peak runoff water management system, including erosion and allowing for greater infiltration and filtering. rates; aid in ground water recharge; provide sedimentation controls, should be constructed settling of pollutants; lower the probability of and stabilized at the start of site disturbance and 10.Stormwater is a component of the total downstream flooding, stream erosion and construction. water resource. It should not be dis- sedimentation; and provide water for other 8. The stormwater management system must carded casually but should be used to beneficial uses. Where practical, the “blue- be designed beginning with the outlet or replenish those resources. Stormwater green” approach to development which in- point of outflow from the project. The represents a potential resource that is out of cludes lakes and open space should be used. downstream conveyance system should be place. Its location determines whether it is It inherently provides storage, environmental evaluated to ensure that it has the capacity to a liability or an asset. With the water quantity protection and enhancement of community accept the design discharge without adverse and quality problems that face Florida, we amenities. downstream effects. It may be necessary to must consider stormwater as an asset. Treated 6. Stormwater runoff should never be dis- stabilize the downstream conveyance system, stormwater has many beneficial uses. It may charged directly to surface or ground especially near the stormwater system outlet. be used for irrigation (farms, lawns, parks, golf waters. Runoff should be routed over a longer Another common problem is a restricted out- courses), recreational lakes, ground water re- distance, through grassed swales, wetlands, let, which causes stormwater to back up and charge, industrial cooling and process water, vegetated buffers and other areas designed exceed the storage capacity of the collection and other nonpotable domestic uses.

30 11. Whenever practical, multiple-use tempo- rary storage basins should be an integral component of the stormwater manage- ment system. All too often, storage facilities planned as part of the system are conven- tional, unimaginative ponds which are aes- thetically unpleasing. Recreational areas (ballfields, tennis courts, volleyball courts), greenbelts, neighborhood parks, and even parking facilities provide excellent settings for temporary storage of stormwater. Such areas are not usually used during periods of high rainfall, and the ponding of stormwater for short periods does not seriously affect their primary uses.

12. Storage areas should be designed with

curving shorelines. Curving shorelines in- floodplain during periods of high water. They crease the pollutant load of stormwater dis crease the length of the shore and create also provide a strip along a shoreline which charges. The key to effective maintenance is development opportunities if a blue-green can accept sheet flow from developed areas the clear assignment of responsibilities to an concept of permanent lakes is being used. and help to minimize the adverse effects of established agency such as a local government The increased shoreline also provides more untreated stormwater. or an organization such as a homeowners as- space for the growth of littoral vegetation to sociation, and regular inspections to determine provide more pollutant filtering and a more 14. THE STORMWATER MANAGEMENT maintenance needs. Stormwater system de- diversified aquatic habitat. SYSTEM MUST BE MAINTAINED. Failure signers should make their systems as 13. Vegetated buffer strips should be retained to provide proper maintenance reduces the simple, natural and, maintenance free as in their natural state and should be cre- pollutant removal efficiency of the system and possible. ated along the banks of all water bodies. reduces the system’s hydraulic capacity. lack Vegetated buffers prevent erosion, trap sedi- of maintenance, especially to vegetate systems ment, filter runoff, provide public access, which may require re-vegetating, can in- enhance the site amenities, and function as a 31 32 CHAPTER FIVE STORMWATER MANAGEMENT PRACTICES The control measures discussed in this chapter wide variety of stormwater management and are intended to serve as basic models and per- erosion and sediment control BMPs. haps to stir the imagination of all who are in- To achieve the desired objectives of flood and volved with land development—landowners, water quality protection, erosion control, and developers, contractors, engineers, architects, improved aesthetics and recreation, a stormwa- landscape architects, and the government offi- ter management system must be an integral part cials who develop and implement stormwater of site planning for every project. Although the management programs. The suggested approach basis principles of stormwater management re- is to minimize the adverse effects of stormwater main the same, each project presents slightly dif- through a coordinated system of source con- ferent problems. The many variations in climate, trols. Source controls emphasize prevention and soils, topography, geology, and the planned land reduction of nonpoint pollution and excess storm- use require site-specific design. Each site has its water flow before it reaches a collection system of natural attributes that influence the type and con- receiving waters. figuration of the stormwater management system. Source control is the central theme of the vari- For example, sandy soils suggest the use of infil- ous stormwater management methods or Best tration practices such as retention areas integrated Management Practices (BMPs). The into a development’s open space and landscap- term Best Management Practice refers to that ing, while natural low areas and isolated wetlands practice which is used for a given set of con- offer opportunities for detention and wetland ditions to achieve satisfactory water quality and treatment. Figure 7 summarizes a number of BMP quantity enhancement at a minimum cost. Chap- types according to their feasibility for different soil ter 6 of the Florida Development Manual: A types. Likewise, the size of the watershed dic- Guide to Sound Land and Water Management tates appropriateness of BMPs, as illustrated in (DER, 1988) contains an extensive discussion of Figure 8. the use, design, construction and operation of a

33 Best Management Practices can be classified into two broad categories – Nonstructural and Structural. Nonstructural controls are those which are intended to improve stormwater qual- ity by reducing the generation and accumulation of potential stormwater pollutants at or near their sources. Nonstructural controls are the first line of defense and include practices such as land use planning and management, wetlands and flood- plain protection, public education, fertilizer and pesticide application control, solid waste col- lection and disposal, street cleaning and “good housekeeping” techniques on construction sites. They are prevention oriented and very cost-effec- tive. Structural controls are those which are used to control the stormwater volume and peak dis- charge rate, as well as reducing the magnitude of pollutants in the discharge water through physical containment or flow restrictions designed to allow settling, filtration, percolation, chemical treatment or biological uptake. These practices typically are individually, they often work together as part of maintenance, offer recreational opportunities, land intensive, require proper long term mainte- a total system. wildlife habitat, irrigation, and fire protection. All too often, inadequate or improper design and nance and can be costly, especially in already ur- As noted, the careful design of stormwater man- construction of stormwater systems have produced banized areas. agement systems should be an integral part of unsightly and unsafe facilities that do not perform development planning. Stormwater management A. BMP Treatment Train well and which quickly become maintenance is not—or should not be—an afterthought, and problems. Public acceptance of such projects is A stormwater management system might be con- there are many opportunities to integrate understandably poor, and the entire concept of sidered as a BMP treatment train in which in- stormwater controls into the open space and stormwater management suffers as a result. BMPs dividual BMPs are the cars. Generally, the mo- landscape elements of development. Creative should not be big muddy ponds. rel BMPs that are incorporated into the system, and imaginative design can produce stormwater the better the performance of the treatment train. management systems that not only function Although the different BMPs will be discussed properly but also are aesthetic amenities, reduce 34 B. On-Line Versus Off-Line BMPs On-line BMPs temporarily store runoff before they discharge to surface waters. These systems capture all of the runoff from a design storm. They primarily provide flood control benefits. Water quality benefits are secondary. Off-line BMPs divert the first flush of polluted stormwater for treatment and isolate it from the remaining stormwater, which is managed for flood control. Off-line retention is the most effective water quality protection BMP, since the diverted first flush is not discharged to surface waters but is stored-to be gradually removed by infiltration, evaporation and evapotranspiration. Figure 9 is a schematic of an off-line treatment system in which a smart weir directs the first flush of stormwater into the infiltration area until it is filled. The remaining runoff is routed to the detention facility for flood control.

35 Off-line systems can be designed so that they are integrated with the site’s landscape thus providing an amenity instead of a potential detraction

36 C. The Importance of Vegetation Vegetation provides several benefits in managing stormwater (Figure 10). It absorbs the energy of falling rain, preventing erosion, maintains the soil’s capacity to absorb water, promoting infiltration. It slows the velocity of runoff, reducing peak dis- charge rate. Vegetation is especially important in reducing erosion and sedimentation during construction. By phasing and limiting the removal of vegeta- tion, and by decreasing the area that is cleared and limiting the time bare land is exposed to rainfall, sedimentation at construction sites can be reduced by up to 90%. If large areas of land must be cleared at once, those areas upon which construction will not occur within 7 days should be mulched and seeded to provide immediate temporary cover. Special consideration should be given to the maintenance of vegetative cover on areas of high erosion potential, such as erodible soils, steep or long slopes, stormwater convey- ances, and the banks of streams. Stormwater BMPs which use vegetative cover include overland sheet flow, grassed swales and channels, infiltration areas, and grassed discharge or flow areas for roof drainage. All are particu- larly suited to residential, transportation and rec- reational developments, but also can be use in commercial and industrial sites. 37 The amount and nature of topsoil and vegeta- The amount of infiltration depends primarily on filtration capacity diminishes. To protect ground tion are important factors that affect infiltration of the soil. Successful use of infiltration requires water from contamination, the seasonal high water stormwater. A thick layer of topsoil with dense appropriate site conditions to assure that the table and bedrock should be at least three feet sod provides excellent natural infiltration. Any stormwater will infiltrate within 24 to 72 hours. beneath the bottom of the retention practice. In area under development that is to be revegetated Coarse-grained sandy soils have excellent infiltra- areas where limerock is near the surface and sink- should be covered by an adequate layer of top- tion capacity. As soils begin to contain higher holes are common, special precautions must be soil. The original topsoil at the side should be amounts of fine-grained clays and silts, their in- taken to protect the ground water. removed and stockpiled for reuse to provide a minimum of four inches over areas that have a po- rous sub-soil. In areas of heavy clay, six to eight inches of topsoil will provide proper plant growth and create absorbent soil. D. Infiltration (Retention) Practices In an undeveloped area, infiltration is a natural part of the hydrologic cycle. A certain part of precipitation is absorbed into the ground, replen- ishing the ground water and feeding trees and other plants. Retention BMPs retain storm- water onsite, allowing it to infiltrate into the ground or to evaporate. These practices reduce the volume of stormwater, and are the most ef- fective for reducing stormwater pollution since, typically, the first flush is not discharged to surface waters. By reducing the volume of stormwater, in- filtration also helps reduce the effects of stormwa- ter on estuaries which are vulnerable to too much fresh water.

Infi ltration Practice: Directing root to grassed areas.

38 In areas with appropriate site conditions, off-line Dry Retention Basins or Areas On a small scale, lawn, parking lot islands, and infiltration BMPs should be used where possible. small landscaped areas all can be used to store Nearly every land use in a developing area can Typical retention BMPs include grassed swales stormwater and allow it to infiltrate. Such areas effectively and economically incorporate on-site, (often with check dams), retention basins, infiltra- are especially appropriate as elements of a BMP off-line retention into its design. If site conditions tion areas, and infiltration trenches. With imagi- will not allow total infiltration of the first flush, treatment train where raised storm sewer inlets native design and proper installation, retention then parts of the first flush can be infiltrated as are placed in the retention area allowing some practices can effectively meet the challenges of pretreatment before the stormwater enters a wet treatment before excess stormwater is routed to a aesthetics, safety, maintenance and effectiveness. detention or wetland treatment system for final detention facility. However, as with any portion of a development treatment. project, good solutions do not happen by them- selves. They must be carefully planned as part of the entire development. Off-line infiltration can be easily incorporated into landscaped and open space areas such as natu- ral or excavated grassed depressions, recreational areas, and even landscaped parking lot islands. Some retention practices can be designed as land- scaped rock gardens or picturesque creek beds. Lawns, especially on waterfront property, can be designed to store runoff for a short time. Since retention areas frequently are designed to remain dry when not in use, they can often provide mul- tiple uses—stormwater management during wet weather and recreational, open spaces or parking during dry weather.

39 On a larger scale, retention areas can be designed Side slopes of infiltration areas should be gentle Good vegetative cover and proper drying are ex- into the open spaces of an entire development enough to mow and should be properly tremely important in the design and development or park system. Orlando has been very creative shaped to blend with the surrounding topogra- of multiple-use retention and recreation facilities. in using this concept to modify older stormwater phy. When intended for recreational use, side The basis floor must be properly graded (two systems and reduce the pollutant loading to the slopes can provide an amphitheater for spectator percent slope—more on poorly drained soils) to city’s downtown lakes. Proper design of these seating on grassy banks. Banks can also serve to provide adequate surface drainage and yet must retention systems can insure successful, useful contain balls in the playing area, avoiding the allow appropriate recreational use and avoid low and attractive results. During dry periods, large need for a fence. spots that might remain wet. In some situations, retention areas can serve as parks or community underdrains may be needed to promote infiltration recreation areas. and to help eliminate standing water. By eliminat- ing the possibility of standing water, problems of weeds, algae and mosquitos can be avoided and the multiple uses of the stormwater system can be realized. The natural characteristics of the site must be re- spected and used properly. In many situations, the appropriate appearance of BMPs will be crisp and clear with a certain quality of sophistication. In other instances, especially in parks or residential developments, retention areas can be effectively created in naturalized or wooded areas, further reducing maintenance. With sensitive placement, imaginative design, careful construction and appropriate landscap- ing, stormwater retention facilities can effectively protect property and water quality and still be an aesthetically satisfying part of the community environment.

Proposed spreader swale at Al Coith Park (Orlando). 40 Grassed Swales Swales, or grassed waterways, are one of the a pretreatment conveyance system to reduce oldest stormwater BMPs, and have been used pollutants before the stormwater enters a reten- along streets and highways for years. A swale is: tion and detention basin, or a wetland. Swales should be seen as an important component 1. a shallow trench which has side slopes flatter of a BMP treatment train. than three feet horizontal to one foot vertical; 2. contains areas of standing or flowing water only after a rainfall; 3. planted with or has vegetation suitable for soil stabilization, stormwater treatment, and nutri- ent uptake; 4. designed to take into account the soil erodibil- ity, soil percolation, slope, slope length, and drainage area so as to prevent erosion and reduce the stormwater pollutant load. Traditionally, swales are used primarily for stormwater conveyance, and are considered an on-line practice. As with other retention prac- tices, the effectiveness of pollutant removal de- pends on the volume of stormwater than can be infiltrated through the filtering vegetation and into the soil. Used alone, swales must percolate 80% of the runoff from a three-inch rainfall within 72 hours to provide proper water quality benefits. How- ever, this is often impossible because of soil or slope, and the greatest utility of a swale is as

41 One way to improve the effectiveness of pollu- and holding it-allowing some to soak into the 20 horizontal are recommended. Along residen- tant removal and the infiltration capability of a ground and be filtered by vegetation. On high tial streets and lower speed highways, steeper swale is to place small check dams along the speed highways, safety must be considered, and flow line berm slopes (1:6) are acceptable. swale, or to use raised driveway culverts to a maximum water depth of about 1.5 feet and Figure 11 is an example of a swale with a cross cause stormwater to pond, slowing the runoff flow line slopes on the check dams of 1 vertical/ block.

42 The feasibility of swales depends on land use tems are used, curb cuts should be used wher- and site characteristics. Considerations such as ever grassed areas are adjacent to the road to on-street parking, and small lots with numerous allow some infiltration and treatment of the driveway culverts may be a limiting factor. On stormwater. An effective treatment train can be the other hand, parkways, boulevards, collector formed by using a curb cut in association with streets and streets in large-lot subdivisions may a raised storm sewer inlet which ultimately con- all benefit from using swales. veys the runoff to a retention or detention system. Maintenance requirements for swales will not be significantly greater than those for a normal lawn. However, public education is essential, especially for residents who live in develop- ments served by swales. Residents need to be informed about the benefits provided by their swale so they take pride in maintaining it and do not fill it in. Residents need to know that leaves, limbs and other vegetation, along with debris and oil should not be disposed of in the swale. If this occurs, the pollutants in these materials will be delivered to downstream waters and a benefit of the swale would be lost. Many local governments require curb and gutter systems and prohibit swales. Such policies should be reviewed to determine why they were established and if they can be modified to help reduce stormwater management costs and water quality degradation. If curb and gutter sys-

43 Infiltration Trenches In many urban areas, land costs are so prohibitive To prevent ground water contamination, trench Infiltration trenches can be located on the surface that infiltration basins are not feasible. In such bottoms should be at least four feet above the or below the ground. Surface trenches receive cases an off-lone infiltration trench can be the seasonal high water table. Another important sheet flow runoff directly from adjacent areas primary component of the treatment train. This consideration for infiltration trenches is to use after it has been filtered by a grass buffer. Sur- BMP consists of a long, narrow excavation ranging the treatment train concept to maximize water face trenches typically are used in residential areas from 3 to 12 feet in depth (depending on quality benefits, reduce maintenance require- where smaller loads of sediment and oil can be stormwater volume, soil and water table condi- ments, and prevent the physical clogging of trapped by grassed filter strips that are at lease tions) which is backfilled with stone aggregate, these systems by sediment, leaves and other ma- 20 feet wide. While surface trenches may be allowing for the temporary storage of the first terials. Limestone aggregate should not be used more susceptible to sediment accumulations, flush stormwater in the voids between the aggre- since it has tendency to cement together, thus their accessibility makes them easier to maintain. gate material. Stored runoff then infiltrates into the reducing the void space in which the stormwater Surface trenches can be used in highway medi- surrounding soil. is stored. ans, parking lots and in narrow landscaped areas.

44 Underground trenches can accept runoff from storm sewers and can be applied in many development situations, although discretion must be exercised with their applicability. To prevent clogging, pretreatment is essential. Inlets to un- derground trenches must include trash racks, catch basins and baffles to reduce sediment, leaves, other debris, and oils and greases. Main- tenance or replacement of underground trenches can be very difficult and expensive, especially if they are placed beneath parking areas or pave- ment. The most commonly used underground trench is an exfiltration system in which runoff is diverted into an oversized perforated pipe placed within an aggregate envelope. The first flush of stormwa- ter is stored in the pipe and exfiltrates out of the holes through the gravel and into the surrounding soil. The City of Orlando has installed many ex- filtration systems throughout downtown to reduce stormwater pollution of its lakes. Routine mainte- nance consists of vacuuming debris from the catch basin inlets and, if needed, using high pressure hoses to wash clogging materials out of the pipe. Orlando Streetscape Project Exfi ltration Trench

45 46 46 E. Detention Practices Unfortunately, variations in soil, water table Figure 12 illustrates the basic components of a Technical design criteria for detention systems and geologic conditions throughout Florida pre- wet detention system that is used for flood control have been established by the Department of En- clude the exclusive use of infiltration practices and water quality enhancement. Essentially, a wet vironmental Regulation and the water management in many locations. These locales often have slowly detention “lake” consists of a permanent water districts. These criteria address general concerns percolating soils, high water tables, and flat ter- pool, an overlying zone in which the design runoff that are important to safe, efficient operation of rain typical of the “flatwoods” area of Florida. In volume temporarily increases the depth while it is such systems including: evaluation of runoff hydro- such areas, permanently wet detention systems stored and released at the allowed peak discharge graphs for storms of various size and frequency; and wetland treatment systems are likely to be rate and a shallow littoral zone in which wetland determination of level of flood protection, rate of the preferred BMPs. The concept of the storm- plants biologically remove dissolved stormwater stormwater release; design requirements to maxi- water treatment train is especially applicable to pollutants such as metals and nutrients. During mize pollutant removal; provisions for maintenance; detention systems. The use of swales, landscape storms, runoff replaces “treated” water which and provisions for emergency overflow to protect infiltration areas, and perimeter swale/berms for were detained within the permanent pool after adjacent and downstream properties. pretreatment will greatly improve the pollutant the previous storm. Wet detention lakes are often removal effectiveness, aesthetics and longevity of used in series, with swale interconnections. a detention system. Detention systems are storage areas that maintain a planned permanent level of water even after stormwater discharge has ceased. These perma- nent lakes and ponds, if properly planned and constructed, provide multiple benefits includ- ing improved property values. They provide “lake-front” property, possibilities for recreation and wildlife habitat, water for irrigation and fire protection, and even a source of fill. Detention systems also provide flood protection and very good removal of stormwater pollutants.

47 Once the technical requirements have been Detention systems can be designed to fit almost this section, the problems of safety and mainte- established, they must be translated into physical any new development. Depending on the nature nance as well as the considerations of aesthetic reality through competent design and construc- of the land use, the detention lakes can be re- quality and multiple use can be effectively tion. The same set of technical requirements can fined and sophisticated or natural and somewhat controlled through sound planning and careful be met through a traditional engineering solu- wild. As illustrated by the examples presented in design. tions or through creative design with full appreciation for aesthetic, maintenance, safety and multiple use considerations. The solution shown at right illustrates several im- portant elements in the design of detention sys- tems. The permanent water pool is bordered by a stone edge capped by a concrete coping to give a refined appearance that blends with its landscaped surroundings. The first level of storm- water control is provided within the borders of stone and concrete coping. For storage capacity required by more intense storms, the lawn area surrounding the permanent pond is carefully graded to contain additional runoff. The final level of control is provided by an emergency overflow swale designed to convey stormwater from a very large, infrequent storm, more severe than the design storm, safely away from improve- ments susceptible to damage. The entire appearance of this example is aes- thetically pleasing, provides recreational oppor- tunities and has been skillfully integrated into the overall landscape design of this urban setting. Because of the rock and concrete edging, bank erosion and maintenance are not problems, and the overflow area of the facility is simply main- tained as lawn.

48 49 49 Regional detention systems can be established to provide stormwater management for several projects within a watershed. In addition, regional facilities can provide for water quality enhance- ment and flood protection for existing storm- water problems and, if located and designed as part of an overall stormwater master plan, they can also address stormwater management needs associated with future development. Regional facilities also offer many advantages such as economy of scale for construction and operation costs and greater overall effectiveness. In addition to their stormwater management benefits, regional detention systems also can provide much needed recreational and open Lake Greenwood Urban Wetland space benefits in the urban environment. As part (Conceptual Views) of its Southeast lakes Watershed Project, the City of Orlando constructed a very creative detention system called the Lake Greenwood Urban Wet- land. Besides being an innovative stormwater treatment train, the system also provides an attractive urban wetland and recreational area.

50 Lake Greenwood Before Redesign

Lake Greenwood After Redesign

51 Conceptual Design Pretreatment Pond

Wetland Treatment System Swale Discharge From Wetland 52 F. Wetland Stormwater Systems The contributions of wetlands to a high quality to state waters by such a ditch may be used for ment and microorganisms—that treats the other environment are substantial and irreplaceable. stormwater management. These wetlands have stormwater pollutants. The pretreatment pond Wetlands help improve water quality by trapping been damaged. Typically they are dry and up- also provides stormwater storage and attenuates sediments, filtration and adsorption of pollut- land plants are invading and replacing wetland peak discharges to help protect the hydroperiod ants, and natural flood protection through wa- plants. Using these kinds of wetlands for storm- of the wetland. The hydroperiod—the duration ter storage and conveying flows. Wetlands are water management revitalized them and provides that water stays at various levels—determines the nature’s kidneys. valuable new fish and wildlife habitat and aes- form, function and nature of the wetland. It must thetic benefits. Isolated wetlands that are inter- be preserved for restored. The incorporation of wetlands into a compre- mittently connected and which flow to other hensive stormwater management system pro- Careful attention to detail is essential in the design waters when ground water rises above the land vides a way to achieve many objectives—flood of wetland stormwater systems. The BMPs in the surface also may be used for stormwater protection, water quality enhancement, reduced treatment train must be carefully planned to management. This program has helped to pre- operation and maintenance, aesthetic buffer, de- work together to convey and pretreat storm- serve wetlands that otherwise would have been velopment amenities, enhanced wetland value, water. To protect the hydroperiod, the allow- destroyed or damaged during development, and wetland preservation and enhancement. able high-and-low water levels in the wetland while helping to provide effective stormwater However, the use of wetlands for stormwater must be skillfully determined from field indica- management. management is neither a panacea nor a refined tors. A distribution system that assures sheet flow science. In designing stormwater management systems of stormwater through the wetland must be de- that incorporate wetlands, the stormwater treat- signed to avoid channelized flow and to assure In 1984, the Florida Legislature authorized the use ment train concept is essential. Pretreatment maximum contact of the stormwater with the of certain wetlands for stormwater management practices such as swales, off-line landscape wetland’s vegetation, sediment, and microorgan- if the ecological values of the wetlands were infiltration or a pretreatment pond are needed isms. Imaginative planning and design can create protected or restored. Wetlands that have been to reduce oil, grease and sediment loads to a stormwater system that is attractive, effective, ditched and drained and which are connected protect the wetland filter—the vegetation, sedi- and nearly self-maintaining.

53 G. Detention with Filtration A BMP commonly used in Florida since 1982 is detention with filtration in which stormwater is held in a detention system and then is discharged through a filter. The filter removes particulate pollutants but does not remove dissolved pol- lutants and, therefore, is of limited value for pro- tection of water quality. Typical filter systems have included bottom or side bank sand or natural soil filters. Recently, more exotic tech- niques such as multi-media filters composed of alum sludge or activated charcoal have been tried to improve the ability of filter to remove dissolved pollutants. The Japanese garden filter shown to the right was guild as part of the Lake Eola restoration project but, like other filters, it suffers from design and operation problems. Difficulties associated with the design, construc- tion and, most importantly, the maintenance of stormwater filters has lead the Department of Environmental Regulation to deemphasize use of these systems. Experience shows that it is not a question of whether a filter will clog, but when— and then who will maintain it. Wet detention systems with planted littoral zones should be used rather than detention with filtration. How- ever, where wet detention systems are impracti- cal such as on small sites, sodded bottom filters are an acceptable alternative. The importance of vegetation cannot be over-emphasized for both enhanced treatment and minimum maintenance.

54 H. Parking Lots Parking lots are one of the largest generators of runoff and polluted stormwater. These vast paved deserts generate stormwater after every storm. Many parking areas, such as for shopping centers are rarely completely filled with cars. This sug- gests that local regulations specifying parking requirements might need revision, while our design of parking lots could use greater imagin- ation. The grassed parking lot at Tampa Stadium is a good example of a creative solution.

Another creative design is to recess landscaped islands so they are small retention and pretreat- ment areas. Placing a raised storm sewer inlet in the landscape island helps filter heavy metals, oils and greases. The raised inlet allows some retention and infiltration of the first flush before the stormwater is routed to a detention system. Using a curb cut allows the stormwater to flow into the landscape island easily.

55 POROUS CONCRETE is another innovative parking surface. High pressure steam cleaning BMP with widespread applicability for parking may be needed annually. During construction it If properly designed, installed and maintained, areas. Paving with porous concrete allows water is essential that sound erosion and sediment con- pervious concrete provides a cost-effective, vi- to percolate into the underlying soil. By using trol practices be used to keep sediment off the able solution to parking lot stormwater manage- porous concrete, a parking lot can remain per- pervious pavement and prevent clogging. ment problems. vious and act as a large retention area, thereby reducing stormwater volume, peak discharge rate and pollutant load. In addition, porous concrete eliminates water pockets and provides a safer, skid resistant surface. However, porous concrete is only feasible and cost effective on sites with gentle slopes, per- meable soils and relatively deep water table and bedrock levels. When properly designed and carefully installed, porous concrete has load bearing strength and longevity similar to that of conventional concrete. The design and installa- tion of porous concrete should be done only by a professional team of engineers and contrac- tors who are familiar with its properties. Routine inspection and maintenance is essential to pre- serve the high infiltration rate of porous concrete paving. The surface should be routinely checked after a prolonged storm for evidence of debris, ponding of water, clogging of pores or other damage. Regular vacuum sweeping should be per- formed to prevent clogging of the porous

56 I. Alum Treatment The first application of this technique was in the 1986 restoration of Lake Ella in Tallahassee. Lake Aluminum sulfate (alum) has been used to clarify Ella is a 13-acre shallow lake shoes 160 acre potable water supplies, remove phosphorus watershed is intensively developed. The lack of from wastewater, and to inactivate phosphorus available land, and heavy clay soils prevented the in lake sediments. Injection of liquid alum inside use of traditional BMPs to reduce stormwater storm sewers to treat stormwater represents pollutant loads to the lake. another innovative, cost-effective BMP with widespread application, especially to reduce The Lake Ella stormwater management system stormwater pollutant loads to urban lakes. consists of flow meters which measure stormwater flowing in the storm sewers, and injectors which periodically add a predetermined dose of alum to the stormwater as it moves through the storm sewer. As the alum mixes with stormwater, it produces a small floc which attracts suspended and dissolved pollutants. The pollutants become bound to the floc, which settles and becomes incorporated into the lake’s sediments. An added benefit is that the alum floc attracts pollutants within the lake water itself and removes them also. The system has successfully removed more than 90% of the stormwater pollutants and Lake Ella’s water quality and clarity is outstanding. Lake Ella is once again a heavily used recreational area for Tallahassee residents.

57 The City of Orlando also used alum injection on a project that demonstrates how a commitment to environmental quality and coordination of retrofitting with a new project can provide mul- tiple benefits and substantial cost savings. The City was building a new arena for its expansion franchise in the National Basketball Association. A traditional stormwater management system using underground exfiltration systems was de- signed to treat the runoff from the 42 acres asso- ciated with the new arena and its surrounding parking areas. The cost of constructing this sys- tem was estimated at over $2 million. Because of its past experiences with stormwaterr manage- ment, the City felt that alternative options, namely, a regional approach to stormwater man- agement, were available that could provide additional benefits for less cost. A desirable benefit was retrofitting the existing drainage system that flowed through the project area and discharged untreated stormwater from the 305 acre basin into Lake Dot which is located directly in front of the new arena. The City con- structed an alum injection system that incorpo- rates a dual feed system – one for alum for treatment, and a second for sodium hydroxide to maintain desirable pH levels in Lake Dot – at a cost of $450,000.

58 J. Maintenance of Stormwater Systems The ultimate success of any stormwater manage- Traditionally, well designed and constructed systems are part of the public infrastructure just ment program depends on proper maintenance. systems on industrial and commercial sites like roads or water systems, and they should be If a system is not properly maintained, the possi- generally receive maintenance. One reason for maintained in the same way. Proper easements bility of failure and subsequent downstream this is that the organization responsible for plan- for all stormwater management facilities must damage is very real. Sooner or later, damage will ning, design and construction is also responsible be required, with easements recorded to insure result and the investment in management facili- for maintenance. These facilities are often in- adequate access for maintenance. Easement re- ties will have been wasted. tended to provide a major site amenity and, quirements typically are found within the state as such, require maintenance on the same basis stormwater criteria. Continuing maintenance should be incorporated as does lawn and building care. into the planning and design of stormwater man- Finally, methods to finance the required mainte- agement systems. Along with the consideration However, stormwater systems for residential nance must be a part of the overall stormwater of who is ultimately responsible for maintenance, developments generally have not received management program. The potential for major design decisions concerning safety, soil condi- much maintenance. Inmost cases a property downstream damage and degraded water qual- tions, topography, watershed size, land use, owners association is legally responsible for ity from uncontrolled stormwater makes financing slope of vegetated banks and overall effective- maintenance, but does not have the technical the maintenance of stormwater facilities as impor- ness all have a bearing on system maintenance. ability or the money to do the job. While these tant to the community as road and bridge Proper handling of these elements during design facilities should be designed and build to allow maintenance or sanitary and safety services. and construction can minimize maintenance ac- as much owner maintenance as possible, the tivities and costs associated with stormwater ultimate responsibility for continuing maintenance management. should be a local government’s. Stormwater

59 60 60 CHAPTER SIX STORMWATER REGULATORY PROGRAMS In the past, the problems caused by increased A. Federal NPDES Stormwater Permitting stormwater runoff were borne by downstream Section 402(p) of the 1987 Federal Clean Water property owners and governments. However, Act requires the U.S. Environmental Protection court decisions have established that the respon- Agency (EPA) to establish National Pollutant sibility and cost for correcting stormwater prob- Discharge Elimination System (NPDES) storm- lems rests with the developer who created the water permits. This permitting program, to be problem, or with the local government which administered in Florida by the EPA, is being phased permitted the development without appropriate in between 1989 and 1992. It will require stormwater management. Landowners, develop- certain local governments to obtain permits for ers, contractors, and local governments must their existing stormwater (drainage) systems and realize the consequences of development on require permits for stormwater from certain the master stormwater system and provide industrial activities. This includes all construction appropriate controls. projects that will disturb five or more acres of Damages caused by stormwater are physical land, government owned landfills, power plants, and visual, environmental and economic, and the airports, vehicle maintenance facilities and waste- cost of correcting the damage always is high. water treatment plants (over 1 MGD flow). The Since prevention of stormwater problems greatest burden will be on local governments through sound site and watershed planning is far which are liable for the pollutants discharged easier than correcting them, stormwater require- from their stormwater systems into Florida wa- ments have been implemented by several levers ters and which will be responsible for developing of government. a long term, comprehensive program to reduce the pollutant loading from their systems.

61 The EPA published final regulations for the Table 3 NPDES stormwater permitting program on Counties Required to Apply for NPDES Stormwater November 16, 1990. Recognizing the need Permits in the Near Future to address stormwater on a watershed basis, (and all municipalities within) the Department and EPA determined that all local governments within a county having a Alachua Collier Leon Pasco population over 100,000 must be included Bay Hernando Manatee Seminole in the program to achieve the desired level of Brevard Indian River Martin St. Lucie stormwater pollutant load reductions neces- Charlotte Lee Okaloosa Volusia sary to keep Florida’s rivers, lakes and estuaries healthy. Table 2 lists counties which, together with their municipalities and the Florida Depart- ment of transportation, must submit permit appli- cations. In addition, once the 1990 census is certified, the counties (and their municipalities) Local governments should begin immediately to modifications of stormwater systems to use listed Table 3 will also have to apply for an use their comprehensive plans to develop an appropriate BMPs to treat the first flush of NPDES stormwater permit. inventory of their stormwater management sys- stormwater, and to remove at least 80% of the tems and to determine their stormwater infra- annual average pollutant load. Stormwater dis- Table 2 structure deficiencies. This information will be charges to Outstanding Florida Waters must be Counties Required to Apply needed to develop the stormwater master plan treated to remove 95% of the annual pollutant for NPDES Stormwater required under both this federal program and the load. state’s growth management program. Permits at Present Sinceits adoption, the Stormwater Rule has been (and all municipalities within) B. State Stormwater Permitting revised several times to keep pace with the rap- idly changing state of the art in BMP design and Broward Orange The state Stormwater Rule, Chapter 17-25 effectiveness. however, the most significant Dade Palm Beach Florida Administrative Code, was implemented change to the state stormwater program occurred Duval Pinellas by the Department of Environmental Regulation with the passage of the 1989 stormwater legisla- Escambia Polk in February 1982. the rule requires all new de- tion. This bill recognized the importance of a Hillsborough Sarasota velopments, redevelopment projects, and most

62 comprehensive approach to stormwater man- found in Chapter 40B-4 (Suwannee River Water C. Local Government Stormwater agement throughout an entire watershed and Management District), Chapters 40C-4, 40C-40 Permitting of the need for a coordinated watershed and 40C-42 (St. Johns River Water Management management team approach involving DER, District), Chapters 40D-4 and 4-D-40 (South- Many local governments have adopted stormwa- the water management districts and local gov- west Florida Water Management District) and ter regulations to protect their citizens from flood ernments. Chapters 40E-4 and 40E-40 (South Florida Water damage, and to protect local water quality. Local Management District). These rules must be con- regulations must be consistent with State Water As a result, State Water Policy (Chapter 17-40, sistent with the goals set forth in State Water Policy and the state and water management dis- F.A.C.) was revised in December, 1990 to estab- Policy. this ensures consistent and equitable ad- trict rules and should not duplicate state permit- lish within Section 17-40.420, the overall goals ministration of the stormwater program through- ting programs. and institutional framework for the state’s out Florida. stormwater management program. these goals As a minimum, local government land develop- include retaining sediment onsite during con- To provide for permitting efficiency and to as- ment codes should ensure that all projects that struction; trying to assure that the stormwater sure comprehensive stormwater management, the will create and discharge stormwater, especially peak discharge rate, volume and pollutant load- Department is delegating its stormwater quality to state waters or to local government stormwater ing from a site are no greater after development permitting program to the water management dis- systems, have received a state stormwater permit than be-fore the land use change; and reduc- tricts. To date, the South Florida Water Manage- or exemption before a local building permit is is- ing the stormwater pollutant loading from older ment District and St. Johns River Water Man- sued. this will help to assure that the stormwater drainage systems so that receiving waters will agement District have received full delegation, is properly treated before discharge to the lo- maintain or be restored to good water quality and the Southwest Florida Water Management cal government system and will reduce the local levels. District and the Suwannee River Water manage- government liability for polluting receiving waters. ment District have received partial delegation. Hopefully, these regulations integrate stormwater, Each of the water management districts (except in the Florida panhandle, all stormwater quality landscaping and tree protection requirements and the Northwest Florida Water Management District permitting currently is conducted by the Depart- coordinate onsite stormwater controls with local which is currently developing rules in Chapters ment. For further information on the delegation of government stormwater master plan and level of 40a and 40-40) has implemented Manage- stormwater permitting to the water management service. The City of Tallahassee’s Environmental ment and Storage of Surface Waters rules to districts or to learn which projects are permit- Management Act is an excellent example of such assure that stormwater is properly managed to ted by the Department or by a District, call the an ordinance. prevent flooding problems and other negative Stormwater Management Section of the Depart- effects on water resources. These rules can be ment of Environmental Regulation in Tallahassee (904/488-0782).

63 Table 4 Watershed Management: A Step by Step Guide

1. Delineate and map watershed boundary and the sub-basins within 9. Identify planned infrastucture improvements—5 year, 20 year the watershed Stormwater management defi ciencies should be coordinated and scheduled with other infrastructure or development projects. 2. Inventory and map natural stormwater conveyance and storage systems 10. Analysis Determine infrastructure and natural resources management needs 3. Inventory and map man-made stormwater conveyance and within each watershed storage system. This includes all ditches, swales, storm sewers detention 11. Set resource management goals and objectives ponds, retention areas, and includes information such as size, Before corrective actions can be taken, a resource management storage capacity, and age. target must be set. The target can be defi ned in terms of water quality standards; attainment and preservation of benefi cial uses; 4. Inventory and map land use by sub-basin or other local resource management objectives.

5. Inventory and map detailed soils by sub-basin 12. Determine pollutant reduction (for existing and future land uses) needed to achieve water quality goals. 6. Establish a clear understanding of water resources in the watershed 13. Select appropriate management practices (point source, Analyze water quality, sediments, and biological data nonpoint source) that can be used to achieve the goal Analyze subjective information on problems (such as citizen Evaluate pollutant removal effectiveness, land owner complaints) acceptance, fi nancial incentives and costs, availability of land Evaluate water body use impairment—frequency, timing, seasonal- operation and ;maintenance needs, feasibility, and availability of ity of problem technical assistance Conduct water quantity assessment—low fl ows, seasonality 14. Develop Watershed Management Plan 7. Inventory pollution sources in the watershed Since the problems in each watershed will be unique, each Point sources—location, pollutants, loadings, fl ow, capacity, etc. watershed management plan will be specifi c. Nonpoint Sources—type, location, pollutants, loading, etc. However, all watershed plans will include elements such as: -land use/loading rate analysis for stormwater Existing and future land use plan -sanitary survey for septic tanks Master stormwater management plan that addresses existing -dry fl ow monitoring to locate illicit discharges and future needs Wastewater management plan including septic tank 8. Identify and map future land use by sub-basin maintenance programs Conduct land use loading rate analysis to assess potential Infrastructure and Capital Improvements Plan effects of various land use scenarios

64 CHAPTER SEVEN WHAT LOCAL GOVERNMENTS CAN DO Local governments are the key to solving A. Develop a Watershed Florida’s stormwater management problems Management Plan because of the intimate relationship between The Local Government Comprehensive Plan- land use, infrastructure, and stormwater man- ning Process offers a unique opportunity to ob- agement. Since local governments determine tain much of the information that is needed for land use, zone property, and issue building per- a local government to develop and implement mits, their commitment to sound watershed man- Watershed Management Plans. As shown in agement is essential. Watershed Management Table 4, the steps taken to develop a watershed involves coordination between land use, infra- plan are similar to those undertaken in the com- structure, and water resources management in a prehensive planning process. In fact, a thorough, well-planned, integrated program that protects well done comprehensive plan can be watershed the quality of life in the most economical fashion. management plan. in their planning process local The stormwater management liability borne by governments should inventory their existing infra- the local government strongly implies a need to de- structure, develop appropriate maps and atlases velop comprehensive stormwater management (such as maps of storm sewer systems), conduct programs that will help to prevent problems in a level of service analyses, determine needs and cost effective manner. it is important to remember problem areas and then, based on future land that successful watershed management requires use, develop and implement their master plan to an integration of nonstructural, preventive ap- meet their needs for infrastructure. proaches (e.g., land use management, source controls) with structural approaches (e.g., BMP implementation).

65 B. Implementation of the Watershed landscaping, tree protection, septic tank siting through the porous soils and rock or sinkholes Management Plan and maintenance. These supplemental regula- characteristic of such regions. tions also should include requirements for various The implementation of a watershed management source controls such as open space, natural areas, Public Education plan, especially recommendations about recon- buffer zones, and even nutrient and pesticide Educating the public about stormwater, BMPs struction of infrastructure such as the modification management. Parking requirements represent an and how our everyday activities can add to the of existing stormwater systems to reduce their area where significant benefits can be realized nonpoint source and stormwater problem is a pollutant loads, requires a stable funding source by minimizing the number of parking spaces or continuous need, not only to reduce the effects over as much as 25 years. Frequently, stormwater the amount of by promoting of these pollution sources, but to gain citizen management can be integrated with other infra- the use of alternatives such as pervious concrete, support for local environmental management structure improvements such as road widening turf block or even grass parking using special programs. or urban redevelopment while water quality im- subgrade materials that provide bearing strength. provements can be coordinated with modified It must be stressed that maximum benefits The public should understand fertilizing lawns flood protection for the existing stormwater and then heavily watering the lawn causes the are realized only if these ordinances are inte- system. Even the development of new parks or fertilizer to run off, creating nutrient problems in recreation areas can be used to address storm- grated, allowing maximum use of nonstructural local waters as well as losing the benefits of the water management needs. The watershed man- preventive controls and promoting use of fertilization. They also should know how a swale agement program should include the following the BMP treatment train throughout the site works, and what benefits it provides. They need elements to help assure successful implementa- planning process. to understand that swales and storm sewers are tion. The Land Development Regulations should not receptacles for grass clippings, tree limbs or other debris, and that used oil and debris should Local Ordinances not duplicate state permitting requirements but should ensure that appropriate state and federal not be dumped into these conveyances since Implementation of the watershed management permits are obtained before a building permit is these materials are soon carried to nearby lakes plan (or Comprehensive Plan) will be achieved issued. Specific criteria which complement or rivers. Programs can be undertaken to stencil storm primarily by the adoption of Land Development but are more restrictive than state requirements drains “DUMP TO WASTES—DRAINS TO Regulations. These will include administrative should be included, if needed, to meet Com- LAKE (RIVER, ESTUARY)” to alert the public to procedures, concurrency management systems, prehensive Plan or local resource management the relationship of these drains to water quality zoning classifications and requirements, sub- objectives. For example, a local government in a problems. division regulations, and supplemental regula- karst area should adopt stormwater criteria that tions that are needed to assure that the objec- help prevent contamination of ground water tives of the watershed management plan are met. Supplemental regulations typically include stormwater management, well-head protection,

66 Pamphlets can be inserted into utility bills to help educate citizens about stormwater management. Informative materials have been developed by the Department, water management districts and local governments to help educate the public. Slide shows and other technical assistance is available from the Department and the water management districts.

67 Funding – The Stormwater Utility – An Inno- TABLE 5 va-tive Source of Money to Get the Job Done Florida Stormwater Utilities The largest obstacle to solving Florida’s storm- IMPLEMENTED ERU RATE UNDER CONSIDERATION water management problems is the lack of ad- 1 TALLAHASSEE $5.00 1 ESCAMBIA CO./PENSACOLA 26 DUVAL COUNTY equate financial resources. 2 GAINESVILLE $3.75 2 PALM BAY 27 LAKE COUNTY 3 OCALA $2.00 3 SANIBEL 28 VERO BEACH To effectively implement a stormwater manage- 4 DAYTONA BEACH $1.75 4 GULFPORT 29 BOCA RATON 5 PORT ORANGE $3.00 5 VOLUSIA COUNTY 30 HIALEAH ment program, local governments need money 6 PORT ST. LUCIE $3.33 6 MANATEE COUNTY 31 BROWARD COUNTY that is dedicated exclusively to stormwater. An 7 MIAMI $2.50 7 PINELLAS COUNTY 32 FT. LAUDERDALE innovative alternative for stormwater manage- 8 OAKLAND PARK $1.00 8 EUSTIS 33 LEESBURG 9 ORLANDO $3.00 9 NEW SMYRNA BEACH 34 BELLE GLADE ment financing is the creation of a stormwater 10 ALTAMONTE SPRINGS $2.25 10 CASSELBERRY 35 CITRUS COUNTY utility which relies on user fees rather than the 11 WINTER PARK $3.50 11 ST. CLOUD 36 POLK COUNTY 12 MOUNT DORA $3.00 12 BAY COUNTY/PANAMA CITY 37 WINTER HAVEN government’s limited general tax revenues. The 13 EDGEWATER $3.00 13 COCOA 38 LAKE WALES utility system is user-oriented, with costs allo- 14 ST. PETERSBURG $4.50 14 ST. PETERSBURG 39 OVIEDO 15 TAVARES $3.00 15 ORANGE CITY 40 MAITLAND cated according to the services received. Parcels 16 DUNEDIN $3.00 16 SEMINOLE COUNTY 41 FT. MEADE of land are assessed a charge based on runoff 17 KISSIMMEE $2.00 17 ORANGE COUNTY 42 MADISON 18 HOLLY HILL $0.50 18 NAPLES 43 LAKELAND characteristics. Charges typically are determined 19 S. DAYTONA $1.00 19 MELBOURNE 44 LEE COUNTY according to a parcel’s size and its percent of 20 ORMOND BEACH $2.50 20 MARTIN COUTNY 45 APOPKA impervious (paved) area. Adjustments can be 21 LARGO $1.50 21 PALM BEACH COUNTY 46 BOYNTON BEACH 22 DELAND $2.00 22 HOLLYWOOD 47 TARPON SPRINGS built into the system for properties which use 23 CAPE CORAL $2.50 23 NEW PORT RICHEY 48 TAMPA appropriate BMPs to manage their runoff. Thus, 24 SARASOTA COUNTY $3.50 24 ATLANTIC BEACH 25 BREVARD COUNTY $3.00 25 BROOKSVILLE user charges are related to a given parcel’s 26 HILLSBOROUGH COUNTY $1.00 stormwater contribution in excess of that contrib- 27 CLEARWATER $3.00 28 W. PALM BEACH $3.50 uted in the natural state. 29 JACKSONVILLE BEACH $3.00 30 DELRAY BEACH $2.25 The stormwater utility concept is not new. It has 31 CLERMONT $3.00 been used by several communities in the western 32 TITUSVILLE $3.00 33 COLLIER COUNTY $3.50 United States since 1969. In Florida, the City of 34 DADE COUNTY $2.50 Tallahassee implemented the state’s first 35 FT. MYERS $3.00 36 LEON COUNTY $1.68 stormwater utility in 1986, with single family resi- 37 LAKE MARY $3.00 dents paying $1.00 per month. Today over 38 SANFORD $3.00 thirty-five other communities have implemented stormwater utilities, and many others are in the the need for integrated stormwater management enacted the first county-wide stormwater utility process of adopting one (Table 5). Recognizing throughout a watershed, Dade County recently that also includes twelve of its municipalities. 68 A successful financing program for each commu- Establish a User Fee System – User charges are set Establish a Permit Fee System – While revenue nity must be based on that community’s needs. at rates sufficient to cover the utility’s annual from a permit fee is minimal, the system estab- however, a high degree of public acceptance and operation, maintenance, capital and debt ser- lishes control on all proposed stormwater government confidence has been demonstrated vice requirements. projects, thus facilitating compliance with the for establishing a stormwater utility program which master stormwater plan. Establish a Developer Contribution System – De- integrates the following components: veloper contributions represent a source of Phase Out General Fund Contributions – Allows capital for constructing new stormwater man- a gradual transition to a full utility, usually over agement facilities. Methods include:

a five-year period. Subdivision dedications that require the devel- Adopt a Stormwater Ordinance – The ordinance oper to construct stormwater management identifies the duties of the local government, facilities and dedicate them to local govern- the users and developers; establishes the legal ment, framework and fee structure; establishes the Fees-in-lieu-of that require developers to pay stormwater management goals, policies and an impact fee for the capital improvements standards, and sets up an operating permit needed to serve the development or pay a system to assure that privately owned facilities portion of the cost for a regional facility that continue to function properly. will serve the development. Prepare Stormwater Master Plan – A comprehen- Availability charge that recover a debt service sive stormwater master plan is needed to charge on a previously constructed facility guide near-term and long-term stormwater which will serve the new development. system improvements and determine cost.

69 C. Operation and Maintenance of the Stormwater System While Florida’s stormwater regulatory program Local governments can also help to assure that assuring that stormwater systems serving com- has helped to minimize adverse effects of stormwater systems are properly maintained. mercial properties are properly maintained. stormwater and has led to the construction of Stormwater systems need to be thought of as Before an Occupational License can be renewed stormwater management facilities, a major prob- part of the community’s infrastructure just like its the stormwater system is inspected by the City lem is how to assure that the facilities, once they roads, water and wastewater systems. The City Engineer’s Office which makes sure the system are properly constructed, are being maintained. of Orlando uses its code enforcement powers to has been maintained and is operating properly. Staffing limitations have prevented the Depart- assure that needed maintenance is performed. Most recently, as part of a thorough revision of ment of Environmental Regulation or delegated The City of Altamonte Springs has considered its Environmental Management Ordinance and water management districts from conducting in- using Occupation License renewal as a means of the implementation of its stormwater utility, the spections and emphasizing compliance and City of Tallahassee implemented a stormwater long-term maintenance. Local government assis- operation permit system that requires regular tance is needed to help assure that the tremen- maintenance of the stormwater system and peri- dous investment in stormwater management infra- odic renewal of the operating permit. Currently, structure continues to provide benefits. Since the Department is working with the Florida Water most of these systems discharge into local gov- and Pollution Control Operators Association to ernment stormwater system, it is imperative to develop a standardized curriculum and certifica- make sure that they function properly to minimize tion program for local government stormwater liabilities to local government. maintenance staff. Local governments can help tot inspect storm- D. Intergovernmental Coordination water systems during construction. They already Since stormwater does not recognize political have building inspectors who travel to develop- boundaries it is essential that local governments ment projects to conduct various inspections. If within a watershed work together to develop and properly trained, these inspectors could greatly implement their stormwater master plan. Coordi- improve the effectiveness of Florida’s stormwater nation with the Department, water management program. Training programs for local government districts, and the Department of Transportation inspectors hopefully will be developed by the is also needed as is cooperation with the private Department and water management districts in sector. THE WATERSHED MANAGEMENT the near future. TEAM NEEDS YOU!

70 CONCLUSION 4. COMMUNICATION is essential to edu- cate ourselves about how we are all part of the Proper stormwater management is vital to the problem and how we can and must be part of health of Florida’s economy and our quality of the solution life. Properly designed stormwater management is a practical, feasible and desirable element in 5. COORDINATION of stormwater retrofitting urban development and redevelopment. to reduce pollutant loading with other in- Stormwater can be controlled in conjunction frastructure improvements or redevelopment is with development of any site. The particular con- needed for cost-effective implementation and trol strategy should be tailored to fit the needs to maximize benefits of the individual project by sound selection of 6. CREATIVITY in both BMP technology and in appropriate BMPs, good technical and aesthetic our approach to solving complex problems is design, and quality construction and maintenance. vital Effective watershed management programs must 7. COMMITMENT to solving these problems be based upon the big C’s of watershed manage- so our children will have a bright future (JUST ment: SAY NO TO STORMWATER POLLU 1. COMPREHENSIVE management of land use, TION) will depend upon putting our money water resources and infrastructure throughout where our mouths are. a watershed This guidebook has presented a variety of ap- 2. CONTINUITY of stormwater and watershed proaches to control stormwater. We hope it will management programs over a long period of be a resource of ideas and will stimulate imagina- time will be required to solve these problems tive new solutions to our watershed management 3. COOPERATION between state and local problems. governments, cities and counties, the public and private sectors and all of our citizens is essential to prevent and solve problems

71 The Florida Development Manual: A Guide to Sound Land and Water Management, 1988 INFORMATION Stormwater/Nonpoint Souirce Management Section, Florida Department of Environmental Regulation, SOURCES Tallahassee, Florida Controlling Urban Runoff, A Practical Manual for Planning and Designing Urban BMPs, 1987 Metropolitan Washington Council of Governments Ohio Stormwater Control Guidebook, 1980 Ohio Department of Natural Resources A Guide to Protecting Coastal Waters Through Local Planning, 1986, Division of Coastal management, North Carolina Department of Natural Resources and Community Development Principal Aquifers in Florida, 1975, Florida Bureau of Geology, May Series 16

Mr. Jim Lewis – for his editorial excellence ACKNOWLEDGMENTS Ms. Cynthia Courson – for her word processing expertise North Carolina Department of Natural resources and Community Development – for the figures on pages 6, 12, 16, and 20 LB Desktop Publishing and Graphic Design – for the book layout Mr. Randy Hollingsworth, Post, Buckley, Schuh & Jernigan – for preparation of the line drawings in this booklet Photography courtesy of: Ohio Department of Natural Resources (page 48) Mr. Stephen Lienhart (pages 28 and 49) Ms. Carla Palmer (page 40, 45, and 50) Mr. Clark Hull (page 52) Mr. Robert Day (page 67) Mr. Gary Maddox (page 13) 72 Mr. Eric Livingston (others)