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North Central Texas Council Of Governments TO: Storm Water Program Participants DATE: July 15, 2002 FROM: Jeff Rice, Environmental 􀁐􀁬􀁡􀁮􀁮􀁾􀀠SUBJECT: Menu of Management Program Options
for Post-Construction Dear Storm Water Program Participants: Enclosed is the draft Menu of Management Program Options for the Post-Construction Storm Water Management Minimum Control'Measure.
The current version contains information from the workshops that were held in April, as well as EPA guidance documents and other sources. This version has been reviewed internally by
NCTCOG staff and has received limited 9utside review, and we are now seeking further input on the document. Please look over the Menu of Options and provide any comments that you have
regarding the document. Please provide your comments by July 26, 2002 by whatever format is most convenient (e-mail, fax, phone). Based on the number and type of comments that we receive,
we may convene a committee of participants to review the comments and develop the final version of the text. Please indicate along with your comments whether you would be willing to
participate on such a committee that would meet once or twice to finalize the document. Once the final version is completed, we will send the updated version to you and post it on the
web, We hope that the Menu 01 Management Program Options is useful in your efforts to develop your management program for Post-Construction Storm Water Management and look forward to
your comments. Please feel free to contact me at jrice@dtwinfo.com or 817-695-9212 if you have any questions. Also, please note that the Menu contains information on the Comprehensive
Drainage Criteria and Design Manual, which will be a tool to implement the concepts included in the Menu 01 Options lor PostConstruction, The CDCD Manual is a separate cost-share project
being initiated by NCTCOG's Public Works Council to assist local governments in managing storm water in their jurisdictions and meeting TPDES permit requirements. If you have any questions
about the CDCD Manual, please contact Kenneth Calhoun, NCTCOG, at kcalhoun@d!winfo.com or 817/695-9224. 616 Six Flags Drive, Centerpoint Two . P. O. Box 5888, Arlington, Texas 76005-5888
(817) 640,3300 FAX,817-640-7806 ® recycled paper http://WMv.dfwlnfo.com 
MENU OF MANAGEMENT PROGRAM OPTIONS Post-Construction Storm Water Management in New Development and Redevelopment The following "Menu of Management Program Options" has been developed
from a number of sources, including suggestions by Regional Program participants at the Post-Construction Storm Water Workshops, EPA documents, and others. Participants may consider
these options in the process of developing the post-construction component of their municipal storm water management plan. These suggestions do not represent the complete universe of
alternatives available, nor do they represent an attempt to present a packaged storm water management plan. It is the responsibility of each city or county to develop a complete storm
water management plan that meets the regulatory requirements. Consider the regulatory goal of "maximum extent practicable" (MEP) when developing your storm water management plan and
realize that implementation of the plan and related ordinances becomes a condition of your storm water permit. Prepare a plan that is functional and can be implemented effectively in
your jurisdiction. The italicized text included below is the language for the "Post-Cons,truCtion Storm Water Management in New Development and Redevelopmenf' Minimum Measure taken from
EPA's Final Phase II Rule. The Final Phase II Rule establishes the minimum 'requirements that TNRCC will use in drafting the corresponding storm water permit for small municipalities'in
Texas. Cities and counties should use these requirements in planning their stonilwater management programs until TNRCC issues the Texas permit (TNRCCmust issue the Ptiase II municipal
stbrm water permit by December 9,2002). " t" , You must develop, implement, and enforce a programto address storm water runoff from new development and redevelopment projects thatdislurb
greater than or equal to one acre, including projects less than one acre that are part ofa larger common plan ofdevelopment or sale, that discharge into yoursmall MS4. Your program must
ensure that controls are in place that would prevent orminimize water quality impacts. You must: • Develop and implement strategies which include a combination of structural andlor nonstructural
best managementpractices (BMPs) appropriate for your community; • Use an ordinance or other regulatory mechanism to address post-construction runoff from new development and redevelopment
projects to the extent allowable under State, Tribal or local law; • Ensure adequate long-term operation and maintenance of BMPs. Guidance If water quality impacts are considered from
the beginning stages of a project, new development and potentially redevelopment provide more opportunities for water qualityprotection. EPA recommends that the BMPs chosen: be appropriate
for the local community; minimize water quality impacts; and attempt to maintain pre-development runoff conditions. In choosing appropriate BMPs, EPA encourages you to partiCipate in
locally-based watershed planning efforts which attempt to involve a diverse group of stakeholders including interested citizens. When developing a program that is consistent with this
measure's intent, EPA recommends that you adopt a planning process that identifies the municipality's program goals (e.g., minimize water quality impacts resulting from post-construction
runoff from new development and redevelopment), July 9, 2002 
implementation strategies (e.g., adopt a combination of structural and/or non-structural BMPs), operation and maintenance policies and procedures, and enforcement procedures. In developing
your program, you should consider assessing existing ordinances, policies, programs and studies that address storm water runoff quality. In addition to assessing these existing documents
and programs, you should provide opportunities to the public to participate in the development of the program. Non-structural BMPs are preventative actions that involve management and
source controls such as: policies and ordinances that provide requirements and standards to direct growth to identified areas, protect sensitive areas such as wetlands and riparian areas,
maintain and/or increase open space (including a dedicated funding source for open space acquisition), provide buffers along sensitive water bodies, minimize impervious surfaces, and
minimize disturbance ofsoils and vegetation; policies or ordinances that encourage infill development in higher density urban areas, and areas with existing infrastructure; education
programs for developers and the public about project designs that minimize water quality impacts; and measures such as minimization ofpercent impervious area. Introduction to Post-Construction
Runoff Control BMPs Storm waler best management practices are the primary tool to improve the quality of urban streams and meet the requirements of NPDES permits. Best management practices
are defined as schedules of activities, prohibitions of practices, maintenance procedures, the. use of pollution control devices and other management practices or policies used,to prevent
or reduce the amount of pollution introduced to receiving waters from storm water, runoff. Stated more simply, BMPs are devices or design considerations that are used to reduce the impactsO!
development or human activities on water quality. Used individually or in combination; BMPs are intended to be a cost effective, practicable means to reduce pollutants andlor the arnountof
runoff that reaches receiving waters. The EPA regulations refer to two categories of best management practices, structural and nonstructural (some BMPs such as grassed swales and filter
strips seem to fit into both categories). Structural best management practices are physical devices (i.e., "structures") or landscape features that remove pollutants from storm water
runoff through filtration, infiltration, or detention. Structural BMPs such as wet ponds, infiltration basins, and sand filters are the traditional techniques that have been used to
treat storm water runoff from developments, and are generally incorporated into projects independently of other design considerations for the project. Nonstructural best management practices
are more difficult to define, but involve rethinking the way the built environment is planned and designed, including aspects such as minimizing impervious surfaces (reduced parking
and narrower streets), building in the least sensitive areas of the site, preserving natural streams and riparian buffers, directing runoff over vegetated areas, and providing open space.
Management Program Considerations In formulating a management program to address post-construction impacts, overall objectives for the program should be established for the jurisdiction.
Since many of the structural and non-structural BMPs have water quantity management benefits in addition to water quality benefits, it would be useful to consider a comprehensive storm
water management program that addresses multiple impacts of post-construction storm water runoff. An effective program for managing post-construction runoff should include options for
implementation of both structural and nonstructural controls. Generally, it is cheaper and more effective to implement design elements that prevent or reduce the generation of storm
water runoff andlor pollutants at the source. In many cases, the need for expensive structural controls can be avoided (or they can be July 9, 2002 
reduced in size) if the amount of runoff and entrained pollutants are minimized by the design of the project. Where necessary, structural BMPs used alone or in combination with nonstructural
controls are an effective means of reducing the impact of development on receiving waters. NCTCOG Comprehensive Drainage Criteria and Design Manual In response to the changing regulatory
climate and in recognition of the impact of post-construction storm water runoff on the environment, the Regional Public Works Council, the Regional Storm Water Management Coordinating
Council, and the Trinity River Flood Management Task Force are beginning a multi-year, cost-share project to develop a comprehensive drainage criteria and design manual. The manual,
to be designed in accordance with the Regional Strategy for Managing Storm Water Quality in North Central Texas, will offer step-by-step instructions to help local governments and developers
estimate runoff quantities and select, design, and analyze storm water conveyance facilities that incorporate management practices for storm water quality and quantity mitigation in
new development and redevelopment. The manual will be designed to meet the applicable elements of the post-construction storm water management requirements of MS4 storm water permits.
Specifically, the Comprehensive Drainage Criteria and Desigt:l.(C[)CD) Manual will integrate storm water quality and quantity management with comprehensivestdm1.,water management practices.
The manual will be flexible, yet will contain uniform, consistent 􀁰􀀨􀀶􀀩􀀱􀁩􀀤􀁩􀁾􀁮􀁳􀁦􀁯􀁲􀀠specific levels of seNice that will be applicable to projects of all sizes and locations
in th€i r!;lgion•. , The manual will be available in both traditional hard copy and in electronic format with a. u:>er,friendly, adaptable program for performing hydrologic and hydraulic
analyses andonc!irie c!:>:mpatioility with links to web sites and other technical data. Soils information and current ioel'll 􀁲􀁡􀁩􀁨􀁦􀁾􀀱􀁉􀀠dalawill be included, and recommended
recommended best managemeni practiqes.will be Qusto'mized'for'the North Texas Region. The COCO Manual will 􀁳􀁩􀁭􀁰􀁬􀁩􀁦􀁹􀁣􀁯􀁾􀁳􀁵􀁬􀁴􀁡􀁮􀁴􀁤􀁥􀁳􀁩􀁧􀁮􀁳􀀬􀁣􀁲􀁥􀁡􀁴􀁥􀁣􀀨􀀩􀁮􀁓􀁩􀁳􀁴􀁥􀁮􀁴􀀠runo
ff estimates, faCilitate multijurisdiction drainage analYSis, and enable regipnal training opportunities. The manual will incorporate practices for storm water quality and quantity mitigation
that could seNe as a component of MS4 storm water management plans for post-construction runoff control. The TNRCC has submitted written correspondence to NCTCOG regarding the manual
stating that "Texas Pollutant Discharge Elimination System (TPqES)f1torm water permits for municipal storm sewer systems will contain the requirement that operators (fif these [MS4]
systems develop a minimum control measure for areas of new development and re-development. The TPDES general permit for Phase 1/systems will be issued by December 2002. Development of
the proposed [CDCD] manual, consistent with the requirements ofthis permit, will result in a valuable tool for permittees." Correspondence from Steve Ligon, TNRCC Storm Water & General
Permits Team Leader to John Promise, NCTCOG Director of Environmental Resources, July 8, 2002. Suggested Program Development Schedule The federal Phase II Storm Water Rule states that
"Your NPDES permitting authority [fNRCC for Texas] will specify a time period of up to 5 years from the date ofpermit issuance [March 10,2003 for most jurisdictions] for you to develop
and implement your program." This means that regulated cities and counties will have until March of 2008 to develop and fully implement the storm water management plan, unless TNRCC
modifies this aspect of the EPA rule when it issues its permit, which is unlikely. The following suggested schedule takes full advantage of the allotted time for program development
and implementation for the Post-Construction Minimum Measure since this aspect of the regulations July 9, 2002 
• is likely the most difficult to address. The schedule could be adapted for use by local governments participating in the CDCD Manual project, as well as those who plan to prepare and
implement their own design criteria and standards. The review draft of the CDCD Manual is scheduled to be completed in September 2003 (Permit Year 1) and the final manual is scheduled
to be completed in September 2004 (Permit Year 2). Year 1 (March 2003 -Februarv 2004) • Review existing drainage criteria and standards. • Gather technical information on post-construction
storm water management (could be accomplished through participation in NCTCOG's CDCD Manual or separately by city staff/consultant). Year 2 (March 2004 -February 2005) • Develop draft
criteria and standards for post-eonstruction storm water management, to include both structural and non-structural BMPs (could be accomplished through participation in NCTCOG's COCO
Manual or separately by city staff/consultant). • Initiate review of draft criteria and standards by public works, development services, planning, engineering, administration, planning
commission, and city cO\Jncil/• Prepare procedures for Development Review committee., ' Year 3 (March 2005 -February 2006) • Complete review of and approve criteria and standards (either
NCTCOG COCO Manual, with amendments if necessary, or locally developed criteria and 􀁳􀁴􀁡􀁾􀁡􀀡􀁬􀀮􀁲􀁤􀁳􀀠manual), • Develop and adopt an ordinance requiring regIJlateddevelopmElntand
redevelopment projects to comply with the criteria and 􀁳􀁴􀁡􀁮􀁾􀁡􀁲􀁤􀁳􀀠􀀱􀁝􀀩􀀱􀀡􀀭􀀮􀁲􀀺􀁬􀁩􀁊􀁾􀁉􀀻􀀠iric!\.lginQ 􀁡􀁳􀁹􀁳􀁴􀁾􀁲􀁲􀀬􀁩􀀠of escalating penalties for noncompliance.
􀀬􀁾􀀠. '. ':'>',< 􀀺􀁉􀀺􀁜􀀢􀀧􀁾􀂷􀀢􀀠" ,.'. ,.., • Develop and adopt an or,dil")ari.cll.t9r􀁲􀁴􀁮􀁾􀁩􀁲􀁬􀁴􀁥􀁬􀁊􀀿􀁮􀁣􀁥􀀡􀁯􀁦􀀠post-eonstruction storm water managementBMPs.···· .·.··c.,
/:" '-'." '/;' . • Conduct an inventory ofStrucWral'BMP,s locafedin the jurisdiction. • Develop a program for PIlriodic liispklbtion of both publicly and privately owned BMPs. ! " -􀁾􀀠,
Year 4 (March 2006 -FebruarV2d07r" • Implement Development Review Committee review of all regulated projects, • Implement and enforce. all applicable post-construction storm water management
criteria and standards. ' • Implement periodic inspection program for post-construction BMPs. Year 5 (March 2007 -Februarv 2008) • Continue Year 4 actiVities. • Conduct a review of program
and prescribe changes for succeeding permit term if necessary. Post-Construction Storm Water Management Program Elements Development Review and Approval Process • Implement a Development
Review Committee to review applicable plans to ensure compliance with post-construction storm water management requirements for all regulated public and private development and redevelopment
projects. • Development Review Committee composition could include staff from development services, planning, engineering, public works, and environmental management as appropriate.
• Require a basic environmental inventory consisting of lakes, ponds, streams, drainages, wetlands, protected trees, and soils to be submitted at the earliest stages of site planning.
July 9, 2002 
o Conduct a pre-platting review of development proposals early in the site planning process to outline storm water management requirements and to ensure that non-structural BMP options
are fully explored. o Require submittal of a preliminary storm water management plan including maps, drawings, narrative, and analysis of existing hydrologic conditions, post-construction
hydrologic analysis, storm water management system, and downstream analysis. Site/Project Type Applicability o Adopt minimum regulatory requirement of addressing new development and
redevelopment projects that disturb greater than or equal to one acre, including projects less than one acre that are part of a larger common plan of development or sale. o Consider
regulating new or redevelopment projects that result in the creation or addition of 5,000 square feet or greater of new impervious area. o Consider regulating any commercial or industrial
new or redevelopment, regardless of size, that is required to obtain a TPDES Multi-Sector Storm Water Permit. o Consider placing additional requirements on specific land uses that are
likely to produce higher than normal pollutant concentrations, including retail gas stations, automotivelvehicle service and repair shops, salvage yards, and waste transfer stations.
c; /-,", Comprehensive Storm Water Management Criteria '. . ....., . The following represents an integrated, comprehensive approach to managing storm water quality and quantity. Because
of the synergistic nature of the criteria and multiple benefits to be gained, local governments should consider a similar approach in the management.of post-construction storm water
runoff. The criteria should be developed by qualified storm; water staff. or a consultant based on hydrologic analysis. The proposed Comprehensive D,rainageandCriteria Design Manual
project will result in the development of criteria based on extensive al\alysis of North Texas hydrology and broad input from local government storm water management profeSSionals. Protect
Water Quality o Require all regulated new and redevelopment projects to implement a combination of BMPs (nonstructural and/or structural) designed to remove a specified percentage of
the average annual postconstruction total suspended solids (TSS) load (see note). o Specify that a storm water management system for a site complies with the TSS removal standard if
it is sized to capture and treat the runoff volume from a corresponding appropriately specified percentage of the storms that occur in an average year. Note: TSS was chosen as the representative
storm water pollutant for establishing treatment effectiveness for the following reasons: • The use of TSS as an "indicator" pollutant is well established; • Sediment and turbidity and
other pollutants that adhere to suspended solids (and are consequently removed with TSS) are a significant problem for local urban waterways. Maintain Pre-Development Hydrology o Require
all regulated new and redevelopment projects to control the peak runoff for a specified range of design storm events. PrevenVReduce Flood Damage • Require all conveyance systems to pass
the runoff for a specified design storm event and prohibit development in the full buildout floodplain; and/or • Where structures have already been built in the 1 OO-year floodplain
fringe area, require on-site or regional structural storm water controls to maintain the 100-year floodplain. July 9, 2002 
Consider Downstream Impacts • Require all regulated new and redevelopment projects to perform a downstream hydrologic analysis to determine if there are any additional impacts not addressed
through the previous criteria. • Require the analysis to be performed at the outlet(s) of the site, and downstream at each tributary junction to the point(s) in the conveyance system
where the area of each of the portion of the site draining into the system is less than or equal to a specified percentage of the total drainage area above that pOint. Regulated projects
are required to integrate a storm water management system consisting of nonstructural and/or structural best management practices into overall layout of the project in order to meet
the criteria developed by the local government. Non-structural BMPs are particularly effective since they have inherent storm water quality and quantity benefits, and in addition they
reduce the runoff volume and therefore reduce the size requirements for structural BMPs (see discussion of non-structural BMPs below). . Operation and Maintenance Plans • Require development
submittals to include a plan for operation,and'maintenance of all structural storm water controls and drainage facilities. ' • Plans should contain operation, inspection, and maintenand:H:ictivities,
schedule, and responsible parties; and should also address access and safety issues. <;,' ,',' • Activities to be addressed should include vegetation mainten<jnCe;sediment removal, floatables
removal, mosquito control, and outlet structure maintenance.' ' • Require operation and maintenance plans for 􀁳􀁴􀁲􀁩􀀮􀁪􀀨􀀧􀀺􀁴􀁬􀁬􀁲􀁡􀁬􀀧􀁳􀁴􀀰􀁾􀁭􀀠water'controls to be recorded
with property deed and disclosed lIPon sale or transfer of properties:',,ct., .-., ,. Inspection and 􀁅􀁮􀁦􀁯􀁲􀁣􀁥􀁬􀁔􀁬􀁥􀁩􀁩􀁾􀀻􀀻􀀺􀀠' • Establish appropriate 􀁦􀁲􀁾􀁵􀁥􀁮􀁣􀁩􀁥􀁳􀁦􀁯􀁲􀀠municipa
l inspection during construction of storm water BMPs to ensure proper installation (i.e., once every two weeks, and/or at other required inspections). • Conduct inspections ot'public
and private storm water management facilities to ensure proper operation and maintena,ilGe onan annual baSis (or other appropriate frequency). • Establish procedures f,oF isstiance of
warning notice of violation (with no fine associated) for first time offense. ' ", • Establish provisions for fines for violations, with each day of noncompliance constituting a separate
offense. ' , • Establish provisions for the local government to correct violations and charge the offender for reimbursement of costs incurred. Non-Structural Best Management Practices
Nonstructural best management practices involve rethinking the way the built environment is planned and deSigned, including aspects such as minimizing impervious surfaces (reduced parking
and narrower streets). building in the least sensitive areas of the site, preserving natural streams and riparian buffers, directing runoff over vegetated areas, and providing open space.
This section is organized in accordance with the Develop-Naturally! brochure and accompanying Guide to Developing Naturally that were prepared in response to Phase I MS4 storm water
permit requirements, but are applicable to Phase II permit requirements as well. Note that the Develop Naturally! Brochure and Guide to Developing Naturally in North Central Texas are
available on-line at www.dfwstormwater.comienhancing.html.ormaybeobtainedbycontactingJeffRice.NCTCOG.at jrice@dfwinfo.com or 817-695-9212. July 9, 2002 
The Develop-Naturally! brochure and guide feature ''Ten Keys to Developing Naturally;" keys 1 through 7 of which contain non-structural BMP elements. Under each key below, there is a
brief explanation and rationale for the key followed by potential program elements, which are policies proposed for consideration by local governments. Along with each proposed program
element there is a partial list of ordinances, codes, and other procedures local governments may use for implementation. In addition, providing educational materials to developers will
facilitate compliance with requirements. 1. Maintain existing terrain Incorporating the development into the existing terrain rather than regrading the site helps preserve tree canopy
and other vegetative cover. Maintaining the terrain and natural drainage ways helps to reduce pollution and storm flows from the development and provides protection for environmentally
sensitive features on the site. Potential Program Elements • Limit allowed clearing and grading to the minimum required to install the infrastructure and buildings -Grading Ordinance,
elc • Maintain existing natural topography and drainage patterns of land to be developed -Drainage Manual, Design Review Meetings, etc ... . • Preserve and protect as many trees as possible
-Tree Ordinance, Landscaping Ordinance • Avoid clearing and grading of areas with permeable SOils -Environmental Inventory, Grading Ordinance, etc 2. Minimize impervious surtaces Impervious
surfaces are those such as roads, parking lots, driveways, and rooftops, that don't allow infiltration of storm water intoJh!fground. The inCrease in storm Water runoff, along with the
pollutants the runoff picks up from impt3rvious surfaces, cause major problems for our waterways. Narrower streets and smaller parking lots bel;l¢fitlhe environrrient and can make a
development more attractive as well. . Potential Program Elements . • Develop residential street standards for the minimum required pavement width needed to support travel lanes, on-street
parking, and emergency vehicle access -Street Specifications, Subdivision Ordinance . • Consider limiting on-lltreet parking to one side of the street -Street Specifications, Subdivision
Ordinance • Incorporate sunken landscaped islands in the middle of cul-de-sac turnarounds -Street Specifications, Drainage Manual • Minimize street length by concentrating development
in the least sensitive areas of site -Zoning Ordinance • Reduce parking lot size by lOWering the number of parking spaces (minimum and maximum ratios) and by sharing parking among adjacent
businesses -Zoning Ordinance, Development/Engineering Standards • Reduce parking requirements for developments in proximity to public transportation -Zoning Ordinance • Provide incentives
or opportunities for structured parking rather than surface parking -Zoning Ordinance • Use pavers or porous pavement in parking overflow areas -Development/Engineering Standards • Reduce
frontage requirements in residential areas to reduce road length -Zoning Ordinance • Reduce the rooftop area of buildings by constructing multiple level structures where feasible Zoning
Ordinance July 9, 2002 
3. Build in the least sensitive areas By building in the least sensitive areas, negative impacts on ecologically valuable features are avoided. Areas that should be preserved include
wetlands, floodplains, buffer areas adjacent to streams and lakes, prairies, and stands of mature trees. By increasing the density on the remaining portion of the property, approximately
the same number of building lots or sites can be created compared to "conventional" designs. Potential Program Elements • Require an inventory of a site's natural features including
streams, wetlands, wooded areas, and soils -Environmental/nventory • Require homes, buildings, and parking lots to be located away from streams, floodplains, and other ecologically and
aesthetically valuable areas -Floodplain Regulations, Stream Corridor Ordinance, Zoning Ordinance • Allow higher densities in suitable areas of sites, while preserving ecologically sensitive
or aesthetically valuable features as permanent open space -Zoning Ordinance 4. Provide open space/parks Natural open space is extremely valuable as wildlife habitat, storm watj,r infiltration
areas, and as protective buffers for ecologically sensitive areas. Just as importantibpen space serves as an extension of individual residential lots. Quality open space that prbvidesopportunities
for walking. biking. bird watching, and play is becoming extremely popular witll residents and homebuyers. . ! '.' Potential Program Elements . . , " ; • Implement a program to identify
and acquire 􀁜􀀬􀂢􀁾􀁳􀁩􀁴􀁩􀁶􀁥􀁥􀁣􀁯􀁬􀁯􀁧􀁩􀁣􀁡􀀡􀁡􀁲􀁥􀁡􀁳􀀠as open space or parks OpenSpace and/or Parks M/'!s;ter Plan, /fJpo/pref(erlsive Plan ' 􀀺􀀬􀀧􀁾􀀠• Require a percentage ofdevelopment;silesito bEfprdtepted as'cipen space (10 -20+%. net of roads, easements, floodplain'sietc.y
""ZdhingOrdih.;tnce • Require permanent 􀁰􀁲􀁤􀁴􀁥􀁣􀁴􀁩􀁯􀁮􀁏􀁲􀁯􀁰􀁅􀁭􀀧􀁳􀁰􀁡􀀶􀁩􀁴􀁡􀁾􀁊􀁡􀁳􀀠through acquisition or conservation easements -Zoning Ordinance, Open Space ordinance
• Require developments to proVide direct access to open space areas by residents and the public with trails -Subdivision Ordinance . 5. Preserve streams 􀁡􀁮􀁾flc:icidpfains Natural
streams, floodplaiijs; and riparian buffers are vital to the success of natural systems. Buffered with trees and vegetation;c'rlatural streams also provide extremely important aesthetic
value to neighborhoods and communities. Natural, undeveloped floodplains provide storage for storm flows, minimizing downstream flooding. Potential Program Elements • Require streams
to be maintained in a natural state, or if not possible, require use of bioengineering rather than hard armoring practices -Drainage Manual • Require hydrauliC analyses of streams to
determine flow capacity -Drainage Manual • Require vegetated and wooded riparian buffers along streams (50 feet or more on each side)Stream Corridor Ordinance, Subdivision Ordinance
• Prohibit construction of structures in the "full build-ouf' 1 􀁾􀁏􀀭􀁹􀁥􀁡􀁲􀀠floodplain -Floodplain Ordinance • Prohibit placement of fill material in the 1 DO-year floodplain -Floodp/ain
Ordinance 6. Direct runoff over vegetated areas Discharging runoff from roofs, roads, and parking lots onto vegetated areas, rather than directly into storm drains offers an opportunity
for infiltration of storm water runoff into the ground. Infiltration of storm water runoff reduces both the quantity of water and the amount of pollutants that would otherwise reach
a stream or lake. Landscaped and vegetated areas. particularly in commercial and multi-family residential settings, also provide aesthetic value. July 9,2002 
Potential Program Elements • Require roof drains to discharge onto vegetated areas (rather than driveways and parking lots, or plumbing to storm drains) -Drainage Manual, Development/Engineering
Standards • Require a minimum percentage (10 -20+%) of a parking lot to be landscaped -Zoning Ordinance, Development/Engineering Standards, Landscape Ordinance • Require runoff from
parking lots to discharge as sheet flow into vegetated filter strips bordering the lot -Drainage Manual, Development/Engineering Standards • Require depressed vegetated areas (bioretention)
within and adjacent to parking lots, rather than raised landscaped areas, to allow runoff to infiltrate -Development/Engineering Standards, Landscape Ordinance • Allow/require open drainage
(vegetated swales) where feasible instead of underground storm drain systems -Drainage Manual, Development/Engineering Standards 7. Use Texas SmartScape plants Landscaped areas, with
all of their benefits, can also contribute to the pollution of streams and lakes if they are not managed properly. Using native plants, and those that have been adapted to the local
climate and conditions, decreases the potential for water poliutiCln by riiducing the amount of water, pesticides, and fertilizer that must be applied to keep the plal")tsllealthY -and
saves money. Texas SmartScape is an interactive multimedia tool on compact disk ihatcan'be used to select native and adapted plants for North Texas (more information available atwWw.dfwstormwater.com
). Potential Program Elements ,. "..,. .; ... • Require/encourage native and adapted plantsinlands6aped areas for commercial developments -Landscape Ordinance .' . . .' .' i,'.. '.'
'..' • Encourage native and adapted plants in 􀁬􀁡􀁮􀁤􀁳􀁣􀁡􀁰􀁥􀁤􀀻􀁡􀁲􀁥􀁡􀁾􀀠for commercial developments -Public Education Materials . .' .. .. Structural· Best Management Practices
Structural BMPs such aswet ponds, infiltration basins, and sand filters are the traditional techniques used to treat storm water runoff from developments, and are generally generally
incorporated into projects independently of other design considerations for the project. These controls generally work by capturing and holding a portion of the runoff and then releasing
it slowly over a sufficient period of time to promote settling out of pollutants, resulting in improved water quality and reduce the "peak" flow from the site. Also categorized as structural
BMPs, grassed channels/swales and filter strips treat storm water runoff by using vegetation to filter and settle pollutants. Swales and filter strips also function to attenuate post-development
peak discharge rates for small storm events when compared to concrete channels as a result of runoff velocity reduction and limited infiltration. Detention controls, or dry detention
ponds, fill up during storms but they discharge completely and are dry during the periods between storms. With proper design and maintenance, dry ponds can be used for recreation when
they are dry. Retention controls are known as wet ponds since they maintain a permanent pool of water between storms. The banks and outlet of a wet pond are constructed to provide for
storage and subsequent slow release of storm water runoff. Wet ponds look much like any other pond, and with careful attention to design and maintenance, they can serve as an attractive
water feature in residential and commercial developments. Infiltration basins also collect storm water runoff, but rather than release the water gradually, they hold the water and allow
it (and any pollutants) to infiltrate into the ground. Proper design and construction of infiltration basins is vital to achieve treatment of polluted runoff in the soil path prior to
percolation into ground water. July 9, 2002 
Land intensive or expensive structural BMPs (detention and retention ponds, infiltration basins, and sand filters) should be considered only after non-structural BMPs have been explored
and implemented to the greatest extent possible. In many cases, the need for structural controls can be avoided (or they can be reduced in size) if the amount of runoff and entrained
pollutants are minimized by the design of the project. Generally, it is cheaper and more effective to implement design elements that prevent or reduce the generation of storm water runoff
and/or pollutants at the source. Oil and grit separators fall into a different category of treatment device and are designed specifically to trap oil, grease, and grit, which are common
pollutants generated by automobile use. Oil and grit separators should be considered for use to treat the runoff from high volume parking lots and businesses such as gas stations, car
washes, or automobile service garages. Unlike the other treatment devices discussed above, oil and grit separators offer no benefits for reduction in storm water runoff volume or flow,
but they may be utilized as a pretreatment device upstream of wet ponds, infiltration basins, etc. Potential Program Elements • Incorporate non-structural BMPs, grassed swales, and filter
strips t6 the greatest extent possible. • Evaluate the need for and design retention/detention PQnoi5; sand filters, and infiltration basins after incorporation of non-structural BMPs.
i,i: . ' • Integrate treatment controls in a manner that they function as amenities. • Use oil and grit separators in areas where large amounts of oil and grit can be expected (parking
lots with heavy automobile traffic, gas stations, service'stations);,; The following descriptions of structural BMPs contain linkslo,"BMP Fact Sheets" which were developed for the NCTCOG
Residential/Commercial, BMP Manual. These Fact Sheets contain basic design information for structural best management practices and are included for information purposes only. These
designs are nearly a decade old and no longer represent the state of the art in post-construction storm water management. The designs alsc lack sufficient detail to ensure proper construction
and should not be adopted as part of a drainage manual or ordinance. Through the proposed Comprehensive Drainage Criteria and Design Manual project, NCTCOG intends to develop current
structural (and non-structural) BMP designs specifically tailored for the North Central Texas region. Note: for the purposes of this draft, there are no active links to BMP Fact Sheets.
The BMP Fact Sheet for wet ponds is included as a separate document as a sample of the BMP Fact Sheets. The final electronic version will include live links to all BMP Fact Sheets. Grassed
Swales (Link toBMP Fact Sheet) Grassed swales are storm water conveyances that are specifically designed to filter runoff as it peSses through the swale. Pollutants are removed through
the filtration by the grass, by deposition, and by infiltration into the soil. Grassed swales must be placed on gentle slopes to provide for shallow flow and low velocities. Grassed
swales should also be used on relatively permeable soils to promote infiltration and to prevent standing water. Maintaining healthy cover of turfgrass is essential to performance of
grassed swales. Filter Strip (Link to BMP Fact Sheet) Filter strips are landscaped or natural areas that filter runoff as it flows over vegetation. The vegetation can range from grasses
to woody species, or a mixture of the two. They may closely resemble many natural ecosystems, such as grassy meadows or riparian forests. The dense vegetative cover facilitates sediment
deposition and infiltration, thereby removing pollutants from July 9, 2002 
runoff as it flows over the filter strip. Maintaining a healthy stand of vegetation and periodic maintenance to remove rills or channels is essential to proper function of filter strips.
Sand Filter (Media Filtration) (Link to BMP F;act Sheet) Sand filters are devices designed to remove pollutants from storm water runoff by passing the water through a layer of sand acting
as a filter media. Sand filters typically consist of an inlet structure designed to capture runoff. a sediment chamber to remove excessive sediment. and a concrete basin or chamber to
hold the filter media. Water leaving the filter is collected in pipes underlying the sand and returned to the stream or channel. Sand filters remove pollutants from runoff through the
processes of sedimentation. adsorption. chemical transformation. and decomposition. Since sand filters do not provide for infiltration or detention of runoff. they do not offer any benefits
with respect to downstream flooding or stream channel erosion. Infiltration Trench (Link to BMF! Fact Sheet) Infiltration trenches are shallow excavated ditches that have been backfilled
with stone to form an underground reservoir. Storm water runoff diverted into the trench gradually infiltrates from the trench into the subsoil and eventually into the ground water.
Infiltration trenches are effective in removing both dissolved pollutants and particulates. Infiltration trenches, where feasible, are also effective in preserving pre-development hydrologic
conditions on develop,ed s.ites .. Infiltration trenches are ideal for small drainage areas and may be used as complements tofilter:!!trij)s and swales. Infiltration Basin (Link to BMPFact
Sheet) Infiltration basins or ponds temporarily store storm water runoff until it gradually infiltrates into the soil surrounding the basin. Infiltration basins work onJhe sarne principii;)
as infiltration trenches, but are designed to treat larger drainage areas, and.infiltrate storm water through the basin bottom rather than a trench. Infiltration basins.€lre.lre.effes:tNein'removing
both dissolved pollutants and particulates. Infiltration basins are also effeCtiliein preserving pre-development hydrologic conditions on developed sites. Infiltration basins 􀁣􀁡􀁮􀁾􀁥􀁲􀁶􀁥􀀮􀁲􀁥􀁬
􀁡􀁴􀁩􀁜􀁬􀁥􀁬􀁹􀀠large developments (up to 50 acres in size), . ..􀁾􀀠. Porous Pavement (Link to BMPFact Sheet) . Traditional asphalt and cqncrete are impervious to infiltration of
water, causing storm water to flow off of the road and accumulate in conveyances. Alternatively, porous pavement surfaces allow the infiltration of storm water and associated pollutants
through the pavement into the ground. The most common form of pervious surface for roadway use is a coarse asphalt that has more open pore space than typical asphalt. When performing
properly, porous pavement is comparable in cost and effectiveness to traditional paving techniques and associated storm water management systems. Extended Detention Pond (Basin) (Linkle>
BMP Fact Sheet) Extended detention basins are impoundments that capture a portion of storm water runoff during a storm event and release the stored volume of water slowly over a period
of time. The detention of storm water allows suspended solids, particularly sediment, to settle out of the runoff. Generally, runoff must be retained for approximately 48 hours to provide
adequate settling of suspended solids. Extended detention dry basins are designed to drain completely and to remain dry between storm events. A healthy cover of turfgrass or native prairie
vegetation should be maintained on the bottom and side slopes of the basin to prevent erosion. Wet Pond (Link to BMP Fact sheet) Wet ponds are similar to extended detention basins, except
that a permanent pool of water is maintained. Storage above the base pond elevation is provided to capture and temporarily store runoff and release it at a controlled rate. In addition
to removal of suspended solids through sedimentation, wet ponds are effective at reducing nutrients through biological activity and uptake by aquatic plants growing in and around the
edge of the pond. Wet ponds are usually designed as multipurpose facilities to achieve pollutant removal and peak flow attenuation. Wet ponds require a yearround source of water to maintain
a permanent pool of water. July 9, 2002 
Constructed Wetlands (Vegetated Treatment Pond) (Link to BMP Fact. Sheet) Constructed wetlands are engineered systems designed to simulate natural wetlands in their ability to capture
and treat surface water runoff pollutants. Constructed urban runoff wetlands differ from artificial wetlands created to comply with mitigation requirements in that they do not necessarily
replicate all of the ecological functions of natural wetlands. Constructed wetlands systems provide effective treatment of storm water runoff over a wide range of pollutant loading and
hydraulic conditions. The mechanisms by which wetlands remove pollutants include a combination of sedimentation, adsorption, filtration, chemical precipitation, microbial interactions
and uptake by vegetation. Harvesting of vegetation and maintenance of constructed wetlands are needed to ensure long-term effectiveness. Constructed wetlands require a year-round source
of water to maintain a permanent pool of water. Water Quality Inlet (Oil and Grit Separators) (Unkto BMP Fact Sheet) Water quality inlets are underground retention systems designed to
remove suspended solids, oil, and grease. Water quality inlets, like ponds, rely on gravity settling and retention time to remove large particulates before discharging water to the storm
sewer or other collection system. Oil and grease are trapped by allowing time for them to rise to the surface of the oil separation chamber while the water flows out at a lower level.
Water quality inlets may also .be designed to trap floatable trash and debris. Water quality inlets provide limited treatment of runoff fn)m very small drainage areas. These devices
must be maintained frequently to remove trapped sediment, hydrocarbons, and trash. • July 9, 2002 
􀁾􀁅􀁁􀁾􀁁􀁴􀀭 OFFICE OF •• ASTEWAIER '" :I"'\&nronmenul PrateetlCf'1 Ageoor MANAGEMENIOffice of Water Storm Water , 􀁾􀁈􀁯􀁭􀁥􀀠􀁾􀀠What's New 􀁾􀁆􀁁􀁑􀁳􀀠􀁾􀀠Publications 􀀮􀁾􀀠 ..
Regulations 􀁾􀁏􀁕􀁬􀁲􀁥􀁡􀁣􀁨􀀠.. Llnkll 􀁾􀀠Contacts • PHASE II BMP AND MEASURABLE GOAL EXAMPLES POST-CONSTRUCTION STORM WATER TopicsMANAGEMENT IN NEW I I DEVELOPMENT IREDEVELOPMENT
MINIMUM Measurable Goals MEASURE Part 1: Background & • EPA's 􀁒􀁥􀁧􀁵􀁬􀁡􀁴􀁯􀁲􀁹􀁒􀁾􀁧􀁊􀁬􀁪􀁲􀁥􀁭􀁥􀁮􀁴􀁳􀀠Regulatory £Q:ntext • BMP: 􀁒􀁥􀁤􀁵􀁾􀁥􀀠direcJl)' conn(:)cted 􀁩􀁊􀀱􀀱􀀤􀀭􀁾iouS
surfaces throue:h the use of low impact Part 􀁾􀀮􀁕􀀺􀀧􀁾􀀧􀁌􀀱􀀹􀀢􀀧􀀡􀀠: Developing development and better site design 􀁴􀁥􀁣􀁨􀁾1 􀁵􀁥􀁾􀀠i ti!easurgtdliJ Goaf::ij Under I £i{meral
• BMP: peyeIOp-.lLprQg]JlmioLJ11aintenanceof Perm.ltstructural storm water controls • BMP: Peve10p .and implement a storm w ater f..art 3: 􀁅􀁾􀁦􀁦􀁩􀁐􀁊􀂧􀀠ofordinance and guidance
or a design manJ1al that Pb..e11.BMPs & 􀁁􀁓􀀤􀁾􀀡􀁉􀁄􀁭􀀡include performance standards desigl]ed ed to 􀁍􀀡􀀡􀂧􀁵􀁲􀁾􀁬􀁥􀀮􀁾􀁯􀁡􀁬􀀬􀁾co@ol runoff iJ11/2ilcts Part!; 􀀲􀀰􀀰􀁾􀁾for
New development and significant redevelopme nt 􀁾􀁹􀁥􀁬􀁯􀁰􀁩􀁮􀁱􀁊􀀩􀁾􀀠Water Mangggmgolprojects offer a host of opportunities to install Progrsmstructural runoff controls on both the
site and regional scales. 􀁾􀁮􀁶􀁩􀁲􀁯􀀮􀁊􀀱􀁾􀀠IndicidQ[§ for §iorm !yater 􀁐􀁲􀁯􀁧􀁲􀀮􀁾􀁭􀁳Hypothetical Case Study: Smalltown, USA, has substantial existing development and many neighborhoods
that are still growing. For existing II Menu of BMP. development, the City plans to use on-lot treatm ent to. 􀁾􀁴􀁯􀁲􀁭􀀠Weter Phase II handle some storm water by disconnecting i impervious
surfaces. The City also wants to ens ure that existing storm water controls are functioning properly. Growing areas will also be targeted by requiring impervious area disconnection and
new storm water controls. Minimum Measure Objective: Reduce the volume and improve the quality of storm water runoff by disconnecting impervious surfaces and installing and maintaining
structural storm water controls . 19.11 BMP: Reduce directly connected 􀁩􀁭􀁾􀁲􀁶􀁩􀁯􀁵􀁳􀀠surfaces in new developments and redevelopment projects by reguiring that grassed swales or
filter strips be installed along rQadsides inJieu of curbs and gutters Measurable Goal: Directly connected impervious road surfaces in new developments and redevelopment areas will be
reduced by 30 percent (relative to the traditional scenario in which curbs and gutters are used) over the course of the first permit term. tp:/lwww.epa.gov/npdeslstormwater/measurablegoals/ex5.htm
4/1112002 
Justification' Opportunities abound to provide treatmC'nt and infiltration of runoff in the oht-of-way adjacent to roads. This prac ; would provide onlot treatment of storm water, reduce
the total volume of storm water being discharged from sites, and increase the time of concentration of the runoff that is generated from road surfaces. I.Oj) BMP: Develop a progrll!ll
for maintenance .9f structural storm water controls Measurable Goals: In the first year, conduct an inventory of structural runoff controls. In year 2, develop a GIS to integrate the
location of these controls with schedules for regular inspection and maintenance. Conduct four inspections of each structural control per year and conduct regular maintenance as prescribed
for each type of practice. Justification: There are many structural controls located throughout the municipality that are owned and operated by both public and private entities. Before
a comprehensive maintenance plan can be implemented to address all of the practices, a complete list of BMPs and their locations and site conditions needs to be compiled. An inspection
and maintenance schedule can be developed to maximize efficiency and minimize labor requirements. The system can be expanded to include other types of MS4 maintenance, including street
sweeping, catch basin cleaning, stOtm drain flushing, etc. ThR BMP: Develop and implement a storm water ordinance and guidance or a desigILI1lI).J]IL3!Jhat include 􀁰􀁥􀁲􀁦􀁏􀀡􀁬􀀡􀀡􀁏􀁏􀀮􀁣􀁾􀁳􀁴􀁡�
�􀀹􀁍􀁤􀁳􀁁􀁾􀁳􀁩􀁧􀁮􀂧􀁴􀀺􀁬􀁊􀀨􀀺􀁵􀀻􀀺􀁳􀁭􀁴􀁲􀁊􀀻􀀾􀁌􀁲􀁵􀁬􀀱􀁯􀁦􀁦􀀠impll.cts Measurable Goal: By year 3 of the permit term, 95% of all building permits will include descriptions
and plans regarding storm water control practices and site designs that comply with the criteria and guidance specified or referenced in the municipal code. Justification: Ordinances
are an effecti ve way to establish performance standards for runoff controls. These performance standards might, for example, specify a target for percent removal of annual post-development
total suspended solids loadings, require maintenance of annual ground water recharge rates, or limit runoff volumes and rates such that receiving waters are not negatively impacted.
I I1I!AJiQME PAGE I 􀁑􀁦􀁆􀁉􀁾􀁅Of WAll!!! I 􀁾􀁦WASTEWATERJoIMIAGJ;ME!!!I I I DISCLAIM.&I!. I PRIVACV AND SECURITY I 􀁾EPA I !:llMMmIli I URL: 􀁨􀁬􀁴􀁲􀀺􀁬􀁬􀁷􀁜􀀧􀁲􀁷􀀮􀁃􀁰􀀻􀀱􀀮􀁧􀁯􀀧􀁴􀀯􀁮􀁰􀁤􀁣�
�􀁍􀁏􀁦􀁭􀁜􀁜􀀧􀀮􀀱􀁦􀁴􀁲􀀯􀁭􀁥􀁡􀀮􀀺􀀮􀁵􀁦􀀳􀁢􀁬􀁾􀁧􀁲􀁯􀁬􀁳􀁬􀁣􀀩􀀮􀀬􀀵􀀮􀁨􀁬􀁭􀀠LlSlmodific;i: 12r.:711001 17:11:49 • tp:/Iwww.epa.gov/npdeslstOtmwater/measurablegoals/ex5.htrn 4/1112002

POST CONSTRUCTION 'STOIRM .....·TeD -" . ,} , , 􀀿􀁜􀁦􀁩􀁊􀁦􀁩􀁴􀁴􀀿􀀻􀀦􀀢􀂱􀁖􀁩􀀤􀀻􀀺􀁷􀀺􀁴􀁾􀀬􀀣􀀠􀁾􀀴􀁐􀁩􀁧􀀦􀀠Storm Water , ",: • 􀁟􀁾􀀬􀀮􀁟􀀮􀁟􀀠. CONTROL IN NEWDE1ifEL.OPM , ,
..." . . . ALTERNATIVE TURNAROUNDS o The reduction in impervious cover .. o The number of turnarounds modified: o Whether or not development codes 􀀢􀀧􀀻􀁾􀁩􀁥􀁣􀁨􀁡􀁮􀁧􀁥􀁤􀀠to allow
alternative turnarounds. . .... o The riduction iri,runoff quantity.',,' " o Changes in the physiCal characteristics of streams downstream from modified areas. "., ALTERNA,TrvE PAVERS,
' , " .'. " o Whether'or not develoPment codes were changed to allow for alternative, pavers.:!: o The amount of new alternative paver installations added qf'i!iplaced. .' , '.,,; ,
o The nUfoi>er of new 􀁤􀁾􀁹􀁹􀁬􀁯􀁰􀁭􀁥􀁮􀁴􀀠site,srnlit use alternatiye, pavers.:;},\ . ";:,:' o The reguction in runoff quantity. <,,;.::,: o Chan'g#in the 􀁰􀁨􀁹􀁳􀁩􀀹􀁩􀁩􀁬􀀮􀁣􀁨􀁡􀁲􀁡􀁣􀁴􀁥􀁲􀁩
􀁳􀁴􀁩􀁣􀁳􀁾􀁦􀀠streams downstreanl from areas\"ith alternative'paver installations. . :';;';'. 􀁾􀀮􀁾􀀾􀀬􀀠' , ,"-,!' , ' '." , ALUM INJEcnON ,,'>,'. "',;. o Whether or not an in\;ehiory
of siteswneiealum injectiori:was used 􀁷􀁡􀁳􀀺􀁤􀀹􀁭􀁰􀁬􀁥􀁴􀁥􀁤􀀮􀀺􀀢􀁾􀂷􀀺􀀺.:" _ ,', ". ", : f};:'. '. o 􀁃􀁨􀁡􀁮􀁧􀁥􀁾􀀠in water quality :,:\ii:':.. o Chariges in biologicaJ PoPulations."'"
. . . ' , ._.' <' , "'-:..:i:·' . '::.•􀀬􀀢􀀮􀀺􀀡􀀬􀀺􀀢􀁾􀀬.•.􀁾􀀮􀁟􀀬􀀺􀀮􀀬􀀻􀀮􀀬􀀻􀁾􀀬􀀻􀀮􀀬􀀷􀁾􀀮􀀬􀀧􀀺􀀭􀀮􀀧􀀠-.􀂷􀀮􀁾􀀬􀀮􀀺􀀬􀁲􀁾􀀮􀀺􀁾􀀮􀂷􀁾􀀬􀀺􀀮􀁾􀀬􀀻􀀮􀁦􀀧􀀻􀀢􀀠-'.--... , 􀀭􀀺􀁾􀀭􀀿􀁴􀀮􀁴􀀻
􀁾􀀮􀀭􀁾􀀠BIOReT.;p!nONJ/it:; . 􀂷􀁊􀁬􀁾􀁾􀁜􀀠o The reduction in imperyious cover. ".:"g'\' o The 􀁾􀁤􀁵􀁣􀁴􀁩􀁯􀁮􀀠in runof'fguantity. )i'/. LISt of Measurable ,.',:::Parameters , 􀀬􀀧􀀮􀁾􀀬􀀠:
Measurable Goals ! :" ," ; 􀁾􀀧􀁾􀁾􀁾􀀱􀁲􀁩'Outreach & educatIon on Storm 􀁾􀀠"'.' , Water Impacts InvolvementIPartlclpation Illicit Dlscharoe Detection & Elimination 􀁃􀁯􀁮􀀬􀁾􀁴􀁲􀁵􀁣􀁴􀁩􀁯􀁮􀀠SUe
Storm W8tei Runoff ControJ i 􀀬􀀺􀁾􀁾􀀻􀁩􀁻􀀢􀀬􀀮􀀠i po;st 'Construction lt2rm 􀁗􀁡􀁬􀁅􀁩􀁤􀁾􀁵􀁮􀁯􀁦􀁦Control In New Oevelopl.11rul!..l. ..􀁒􀁥􀁤􀁦􀀻􀁾􀁊􀁏􀁰􀁭􀁥􀁮􀁴􀀠􀁐􀁑􀁉􀁾􀁾􀁾􀁑􀁮􀀠Preventlon!Go
od i 􀁈􀁯􀁵􀁳􀁥􀁫􀁥􀀦􀁰􀁩􀁾􀁧􀀠tor MunicIpal Operations •"i":" ' 􀁍􀁾􀁾􀁾􀀧of 􀁓􀁍􀁾􀁳􀀠,,' o ChangeS'in runoff wiliet quality (nutrie'iits, sediments; metals, organics, 􀁥􀁴􀁣􀀮􀀩􀀮􀀺􀀺􀀺􀀻􀁾􀀻􀁾􀀺�
�􀀠o The number of new bioretention cells installed (both coi:nmercial and 􀁲􀁥􀁳􀁩􀁤􀁥􀁮􀁴􀁩􀁾􀀩􀀺􀀺􀁾􀀷􀁩􀀻􀀻􀀠,.•.•. . ',;\; . o The number of acres that are drained by bioretention
cells. BMP INSPEcnON 􀁁􀁎􀁲􀁩􀁾􀁁􀁉􀁎􀁔􀁅􀁎􀁁􀁎􀁃􀁅􀀮􀀬􀀠'. 0 The frequency of inspection and maintenance 􀁡􀁣􀁴􀁩􀁶􀁩􀁴􀁩􀁥􀁳􀀺􀀻􀀧􀀻􀀺􀁾􀀠o The riilinber of problefusthat were identified
and remecIied. o The change in the proPQition ofBMPsthat are well-maintained as a result ofinspection and maintenance. ",' , " p:l!www.epa.gov/npdeslstormwater/measurablegoalsipararn5.htrn
rag'" 1 OJ :>. , " ifo' '-J; .,I I I, " •• I 4/1112002 ,I I 
􀁾􀀺􀀠
Post-Construction Storm Water Management in New Development and Redevelopment The italicized text included below is the language for the "Post-Construction Storm Water Management in
New Development and Redevelopment" Minimum Control Measure taken from EPA's Final Phase II Rule. The Final Phase II Rule establishes the minimum requirements that TNRCC will use in drafting
the corresponding storm water permit for small municipalities in Texas. Cities and counties should use these requirements in planning their storm water management programs until TNRCC
issues the Texas permit (TNRCC must issue the Phase II municipal storm water permit by December 9, 2002). Following the regulatory language, NCTCOG staff has assembled some guidance
materials to supplement the regulations for use by local governments in early progrem assessment and formulation processes. Note that this is not the Menu of Management Program Options
for PostConstruction Storm Water Management, which will be issued at a later date. NPDES Phase II Regulatory Text You must develop, implement, and enforce a program to address storm
water runoff from new development and redevelopment projects that disturb greater than or equal to one acre, including projects less than one acre that are part of a larger common plan
of development or sale, that discharge into your small MS4. Your program must ensure that controls are in place that would prevent or minimize water quality impacts. You must: • Develop
and implement strategies which include a combination ofstructural and/or nonstructural best management practices (BMPs) appropriate for your community; • Use an ordinance or other regulatory
mechanism to address post-construction runoff from new development and redevelopment projects to the extent allowable under State, Tribal or local law; • Ensure adequate long-term operation
and maintenance of BMPs. Guidance If water quality impacts are considered from the beginning stages of a project, new development and potentially redevelopment provide more opportunities
for water quality protection. EPA recommends that the BMPs chosen: be appropriate for the local community; minimize water quality impacts; and attempt to maintain pre-development runoff
conditions. In choosing appropriate BMPs, EPA encourages you to partiCipate in locally-based watershed planning efforts which attempt to involve a diverse group of stakeholders including
interested citizens. When developing a program that is consistent with this measure's intent, EPA recommends that you adopt a planning process that identifies the municipality's program
goals (e.g., minimize water quality impacts resulting from post-construction runoff from new development and redevelopment), implementation strategies (e.g., adopt a combination ofstructural
and/or non-structural BMPs), operation and maintenance policies and procedures, and enforcement procedures. In developing your program, you should consider assessing existing ordinances,
policies, programs and studies that address storm water runoff quality. In addition to assessing these existing documents and programs, you should provide opportunWes to the public to
participate in the development ofthe program. April 3, 2002 
Non-structural BMPs are preventative actions that involve management and source controls such as: policies and ordinances that provide requirements and standards to direct growth to
identified areas, protect sensitive areas such as wetlands and riparian areas, maintain andlor increase open space (including a dedicated funding source for open space acquisition),
provide buffers along sensitive water bodies, minimize impervious surfaces, and minimize disturbance of soils and vegetation; policies or ordinances that encourage infil/development
in higher density urban areas, and areas with existing infrastructure; education programs for developers and the public about project designs that minimize water quality impacts; and
measures such as minimization ofpercent impervious area. Introduction to Post-Construction Runoff Control BMPs Storm water best management practices are the primary tool to improve the
quality of urban streams and meet the requirements of NPDES permits. Best management practices are defined as schedules of activities, prohibitions of practices, maintenance procedures,
the use of pollution control devices and other management practices or policies used to prevent or reduce the amount of pollution introduced to receiving waters from storm water runoff.
Stated more simply, BMPs are devices or design considerations that are used to reduce the impacts of development or human activities on water quality. Used individually or in combination,
BMPs are intended to be a cost effective, practicable means to reduce pollutants andlor the amount of runoff that reaches receiving waters. TheEPA regulations refer to two categories of best management practices, structural and nonstructural (some BMPs such as grassed swales and filter strips seem to fit into both categories).
Structural best management practices are physical devices ("structures") or landscape features that remove pollutants from storm water runoff through filtration, infiltration, or detention.
Structural BMPs such as wet ponds, infiltration basins, and sand filters are the traditional techniques that have been used to treat storm water runoff from developments, and are generally
incorporated into projects independently of other design considerations for the project. Nonstructural best management practices are more difficult to define, but involve rethinking
the way the built environment is planned and designed, including aspects such as minimizing impervious surfaces (reduced parking and narrower streets), building in the least sensitive
areas of the site, preserving natural streams and riparian buffers, directing runoff over vegetated areas, and providing open space. Management Program Considerations In formulating
a management program to address post-construction impacts, overall objectives for the program should be established for the jurisdiction. Since many of the structural and non-structural
BMPs have water quantity management benefits in addition to water quality benefits, it would be useful to consider a comprehensive storm water management program that addresses multiple
impacts of post-construction storm water runoff. Some of the objectives for post-construction storm weter management being considered by EPA in its proposed Construction and Development
Effluent Guidelines (proposed rule release deadline May 15, 2002) include": • remove suspended solids and associated pollutants entrained in runoff that result from activities occurring
during and after development: • decrease the erosive potential of increased runoff volumes and velocities associated with development-induced changes in hydrology; • retain hydrological
conditions to closely resemble those of the predisturbance condition; • preserve stable, natural stream channels including in-stream habitat; • minimize potential for flooding damage
to structures. * Based on Public Meeting Briefing Packet (and referenced document) from EPA Construction and Development Effluent Guidelines Public Meeting held in July 2001. April 3,
2002 
An effective program for managing post-construction runoff should include options for implementation of both structural and nonstructural controls. Generally, it is cheaper and more
effective to implement design elements that prevent or reduce the generation of stonn water runoff and/or pollutants at the source. In many cases, the need for expensive structural controls
can be avoided (or they can be reduced in size) if the amount of runoff and entrained pollutants are minimized by the design of the project. Where necessary, structural BMPs used alone
or in combination with nonstructural controls are an effective means of reducing the impact of development on receiving waters. Structural Best Management Practices Structural practices
to control urban runoff rely on three basic mechanisms to treat runoff: removal of pollutants from runoff using filtration by vegetation or sand; infiltration of storm water runoff and
pollutants into the ground; and detention of runoff to allow sedimentation of suspended pollutants. The following is a brief description of some of the structural BMPs used to manage
post-construction storm water runoff. Filtration BMPs Filtration practices, such as grassed channels/swales, filter strips, and sand filters, treat stonn water runoff by using vegetation
or sand to filter and settle pollutants. In some cases infiltration and treatment in the subsoil may occur. Swales and filter strips also function to attenuate postdevelopment peak discharge
rates for small stonn events when compared to concrete channels as a result of runoff velocity reduction and limited infiltration. Grassed Swales Grassed swales are storm water conveyances
that are specifically designed to filter runoff as it passes through the swale. Pollutants are removed through the filtration by the grass, by deposition, and by infiltration into the
soil. Grassed swales must be placed on gentle slopes to provide for shallow flow and low velocities. Grassed swales should also be used on relatively permeable soils to promote infiltration
and to prevent standing water. Maintaining healthy cover of turfgrass is essential to performance of grassed swales. Filter Strip Filter strips are landscaped or natural areas that filter
runoff as it flows over vegetation. The vegetation can range from grasses to woody species, or a mixture of the two. They may closely resemble many natural ecosystems, such as grassy
meadows or riparian forests. The dense vegetative cover facilitates sediment deposition and infiltration, thereby removing pollutants from runoff as it flows over the filter strip. Maintaining
a healthy stand of vegetation and periodic maintenance to remove rills or channels is essential to proper function of filter strips. Sand Filter Sand filters are devices designed to
remove pollutants from stonn water runoff by passing the water through a layer of sand acting as a filter media. Sand filters typically consist of an inlet structure designed to capture
runoff, a sediment chamber to remove excessive sediment, and a concrete basin or chamber to hold the filter media. Water leaving the filter is collected in pipes underlying the sand
and retumed to the stream or channel. Sand filters remove pollutants from runoff through the processes of sedimentation, adsorption, chemical transformation, and decomposition. Since
sand filters do not provide for infiltration or detention of runoff, they do not offer any benefits with respect to downstream flooding or stream channel erosion. Infiltration BMPs Infiltration
practices, such as infiltration basins and trenches, and porous pavement rely on absorption of runoff into the ground to treat urban runoff discharges. Water is percolated through soils,
where filtration and biological action remove pollutants. In addition to water quality benefits, infiltration April 3, 2002 
practices raduce runoff volume and peak discharge rate. Infiltration of storm water runoff helps to reduce downstream flooding and stream channel degradation and replenishes groundwater
supplies, thus contributing to low stream flow augmentation. Infiltration BMPs must be built on sites where the natural permeability of the soils is high to allow for the maximum possible
infiltration of water. Infiltration Trench Infiltration trenches are shallow excavated ditches that have been backfilled with stone to form an underground reservoir. Storm water runoff
diverted into the trench gradually infiltrates from the trench into the subsoil and eventually into the ground water. Infiltration trenches are effective in removing both dissolved pollutants
and particulates. Infiltration trenches, where feasible, are also effective in preserving pre-development hydrologic conditions on developed sites. Infiltration trenches are ideal for
small drainage areas and may be used as complements to filter strips and swales. Infiltration Basin Infiltration basins or ponds temporarily store storm water runoff until it gradually
infiltrates into the soil surrounding the basin. Infiltration basins work on the same principle as infiltration trenches, but are designed to treat larger drainage areas, and infiltrate
storm water through the basin bottom rather than a trench. I nfiltration basins are effective in removing both dissolved pollutants and particulates. Infiltration basins are also effective
in preserving pre-development hydrologic conditions on developed sites. Infiltration basins can serve relatively large developments (up to 50 acres in size). Porous Pavement Traditional
asphalt and concrete are impervious to infiltration of water, causing storm water to flow off of the road and accumulate in conveyances. Alternatively, porous pavement surfaces allow
the infiltration of storm water and associated pollutants through the pavement into the ground. The most common form of pervious surface for roadway use is a coarse asphalt that has
has more open pore space than typical asphalt. When performing properly, porous pavement is comparable in cost and effectiveness to traditional paving techniques and associated storm
water management systems. Detention BMPs Detention practices temporarily impound runoff to control runoff rates and to provide time to allow for settling of suspended solids and associated
pollutants. Extended detention basins, wet ponds, and constructed wetlands fall within this category. Detention practices remove storm water pollutants primarily by allowing for sedimentation
(gravitational settling of suspended solids). Pond vegetation can also help reduce nutrient loads and also provide terrestrial and aquatic wildlife habitat. In addition to water quality
benefits, properly designed detention structures protect downstream channels by contrOlling peak discharge rates, thereby reducing the frequency of bankfull flooding and resultant stream
bank erosion. Extended Detention Dry Basin Extended detention basins are impoundments impoundments that capture a portion of storm water runoff during a storm event and release the stored
volume of water slowly over a period of time. The detention of storm water allows suspended solids, particularly sediment, to settle out of the runoff. Generally, runoff must be retained
for approximately 48 hours to provide adequate settling of suspended solids. Extended detention dry basins are designed to drain completely and to remain dry between storm events. A
healthy cover of turfgrass or native prairie vegetation should be maintained on the bottom and side slopes of the basin to prevent erosion. Wet Pond Wet ponds are similar to extended
detention basins, except that a permanent pool of water is maintained. Storage above the base pond elevation is provided to capture and temporarily store runoff and release it at a controlled
rate. In addition to removal of suspended solids through sedimentation, wet ponds are effective at reducing nutrients through biological activity and uptake by aquatic plants growing
in and around the edge of the pond. Wet ponds are usually designed as multi-April 3, 2002 
purpose facilities to achieve pollutant removal and peak flow attenuation. Wet ponds require a yearround source of water to maintain a permanent pool of water. Constructed Wetlands Constructed
wetlands are engineered systems designed to simulate natural wetlands in their ability to capture and treat surface water runoff pollutants. Constructed urban runoff wetlands differ
from artificial wetlands created to comply with mitigation requirements in that they do not necessarily replicate all of the ecological functions of natural wetlands. Constructed wetlands
systems provide effective treatment of storm water runoff over a wide range of pollutant loading and hydraulic conditions. The mechanisms by which wetlands remove pollutants include
a combination of sedimentation, adsorption, filtration, chemical precipitation, microbial interactions and uptake by vegetation. Harvesting of vegetation and maintenance of constructed
wetlands are needed to ensure long-term effectiveness. Constructed wetlands require a year-round source of water to maintain a permanent pool of water. Water Quality Inlet Water quality
inlets are underground retention systems designed to remove suspended solids, oil, and grease. Water quality inlets, like ponds, rely on gravity settling and retention time to remove
large particulates before discharging water to the storm sewer or other collection system. Oil and grease are trapped by allowing time for them to rise to the surface of the oil separation
chamber while the water flows out at a lower level. Water quality inlets may also be designed to trap floatable trash and debris. Water quality inlets provide limited treatment of runoff
from very small drainage areas. These devices must be maintained frequently to remove trapped sediment, hydrocarbons, and trash. Non-Structural Best Management Practices Note: The following
was adapted from the Georgia Sformwafer Management Manual, Volume 1, and serves as a tool for assessing your current development regulations/policies and for considering future nonstructural
practices (referred to as Better Site Design Practices) that Gould be included in your stomr water management plan. Implementing Stormwater Better Site Design Practices Communities should
actively promote the use of stormwater better site design as a way to both protect watersheds and water resources, and implement cost-effective and lower maintenance stormwater management.
However, in order to make better site design a reality, local jurisdictions will often need to review their regulations, development rules, community plans and review procedures to ensure
that they support the belter site design concepts outlined above. Often, communities have in place development rules that work against belter site design and create needless impervious
cover and unnecessary environmental impact. Examples include the minimum parking ratiOS that many communities require for retail or commercial development and zoning restrictions that
limit cluster development designs. Some of the policy instruments that need to to be reviewed for compatibility with the better site design principles include: • Zoning Ordinances and
Procedures • Subdivision Codes • Stormwater Management or Drainage Criteria • Tree Protection or Landscaping Ordinance • Buffer and Floodplain Regulations • Erosion and Sediment Control
Ordinance • Grading Ordinance • Street Standards or Road Design Manual • Parking Requirements April 3, 2002 
• Building and Fire Regulations and Standards • Septic/Sanitary Sewer Regulations • Local Comprehensive Plan Below is a set of questions that can be used to review a community's local
development codes and ordinances with the goal of making it easier to implement stormwater better site design. Conservation of Natural Land Conservation Incentives Features and Resources
• Does the community have a viable greenspace (or open space) program (acquisition, requirements in zoning ordinance, etc.)? • Are there any incentives to developers or landowners to
preserve nonregulated (i.e., floodplain) land in a natural state {density bonuses, conservation easements, stormwater credits orl()lfIIer ro e tax rates? , Natural Area Conservation
• Are there any requirements, incentives, or provisions for preservation of importsnt or sensitive environments (mature forests, wetlands, etc.)? • Are there requirements to maintain
streams in their natural conditions? What exceptions are allowed? • Is there an ordinance or reqUirements for the preservation of natural ve etation on develo men! sites? ________._____--l
Tree Conservation • Does the community have a tree protection ordinance? . . Stream Buffers • Are there requirements to maintain a stream buffer? What is the minimum width? • Do the
stream buffer requirements include lakes, freshwater wetlands, or steep slopes? • Do the stream buffer requirements specify that at least part of the buffer 􀁾􀁢􀁥maintained with.undisturbed
vegetation? Floodplains • Does the community restrict or discourage development in the full buildout 1DO-year floodplain? Steep Slopes • Does theQommunity restrict or discourage building
􀁯􀁮􀀡􀁬􀁴􀁾􀁥􀁰􀀠slopes? Lower Impact Site Designs ! Fitting Site Designs to the Terrain • Does the community provide preconsultation meetings, joint site visits, or technical assistance
with site plans to help developers best fit their design concepts to the topography of the site and protE:ict key site resources? Clearing and Grading • Are there development requirements
that limit the amount of land that can be cleared in a 􀁭􀁵􀁬􀁴􀁩􀁾􀁰􀁬􀀱􀁇􀀡􀁳􀁥􀀠proiect? i'Locating Development In Less Sensitive Areas i • Does the community actively try to plan
and zone to keep development ! out of enVironmental sensitive areas? . Open Space Development : • Are open space or cluster development designs allowed? • Are the submittal or review
requirements for open space designs greater than those for conventional development? • Are flexible site design criteria (e.g. setbacks, road widths, lot sizes) available for developers
who utilize open space or cluster design approaches? • Does a minimum percentage of the open space have to be managed in an undisturbed natural condition? • Does the community have enforceable
requirements to establish associations that can effectivelv manaQe ooen space? Nontraditional Lot Designs'-_________---"_-=-"-'CA",re"-",no,,,n.!!t:..:ra=ditional lot designs and shapes
allowed? April 3, 2002 
I ! Creative Development Design I • Does the community allow and/or promote Planned Unit Developments (PUD's) that give the developer or site designer additional flexibility in site
desiQn? Reduction of Impervious Roadway Length Cover • Do roed and street standards promote the most efficient site and street layouts that reduce overall street length? Roadway Width
• What is the minimum pavement width allowed for streets in low density residential developments that have less than 500 average daily trips (ADn? I Building Footprint • Does the community
provide options for taller buildings and structures which can reduce the overall impervious footprint of a development? Parking Footprint • What is the minimum parking ratio for a professional
office building (per 1000 ft 2 of gross floor area)? Is there a maximum parking ratio in addition to the minimum? • What is the minimum parking ratio for shopping centers (per 1000 if
of gross floor area)? Is there a maximum parking ratio in addition to the minimum? • What is the minimum required parking ratio for Single family homes? • If mass transit is provided
nearby, are parking ratios reduced? • What is the minimum stall width for a standard parking space? • What is the minimum stall length for a standard parking space? • Are larger commercial
parking lots required to have smaller dimensions for compact cars? • Is the use of shared parking anrangements promoted? • Are there any incentives to developers tc provide parking within
structured decks or ramps rather than surface parking lots? • Can porous surfaces be used for overflow parking areas? : • Is a minimum percentage of a parking lot required to be landscaped?
• Is the use of bioretention islands and other structural control practiCes within 􀁬􀁡􀁮􀁤􀁳􀁣􀁡􀁾􀁥􀁤􀀠areas or setbacks allowed? I Setbacks and Frontages ! • Are minimum frontage
and setback reQuirements excessive? Alternative Cul-de-sacs • What is the minimum radius allowed for cul-de-sacs? • Can a landscaped island or bioretention area be created within a cul-desac?
• Are alternative turnarounds such as "hammerheads" allowed on short streets in low dens! residential nei hborhoods? Utilization of Natural Using Natural Dralnageways Features for Stormwater
• Are stcrm sewer systems required for all new developments? Are natural Management s stems allowed? Using Vegetated Swales • Are curb and gutters required for residential street sections?
• Are there design standards for the use of vegetated swales instead of curb and utter? Rooftop Runoff • Are there incentives or requirements for rooftop runoff to be discharged to pervious
areas? • Do current grading or drainage requirements allow for temporary ponding of runoff on lawns or roofto s7 April 3, 2002 
AGuide to Developing Naturally In North Central Texas A companion guidebook to the DEveLoP -NATUMt.Ly! brochure DeveLOP -NATtlRAJ.LY/What is Land Development? According to Webster's
Dictionary. it is to make the land (the surfoce of the earth and aU its natural resources) suitable for residential or commercial purposes, North Central Texas has been blessed with
an abundance of tond to develop and a cur'r'ent economy that is second to none.. Deve10pment is ne.ces:sory for the economic viability of this region but, os we are. learning, how this"development"
occurs has 0 profound impo:ct on the natural environment. We are seeing the consequences of our thriving economy and our development practica on the environment we live in. Some of our
most precious natural resources slICh as the Trinity River, the Ancient Cross Timbers Forest, and cur areO Jokes ore being threatened due to impaired _or quality and loss of habitat,
North Centrol Texas has Q great naturaf heritage that can be pre.s:erve.d by enVironmentally enVironmentally sensitive de1,el"pment practices. IOO.ny of the practices for minimizing
the impact of development CM hove. benefits for the developer in tenns of reduced cost and;n attracting patentEol buyerS by incorporoting features that buyers reportedly consider Produced
by the North Central Texas Council of Governments and the local governments participating in the Regional Storm Water Management Program Draft 
A Guide to Developing Naturally In North Central Texas Why develop naturally? Over the last several years. a number of issues have arisen concerning where and how we develop. Many of
these issues have grown out of a dissatisfaction with the predominant pattern of development that has occurred over the last fifty or so years. Nearly total dependence on the automobile
for travel has resulted in traffiC jams and air pollution. Ubiquitous designs for discount stores and fast food restaurants have eliminated local or regional character. Neighborhoods
lack a sense of community. Open spaces vanish as suburbs spread farther out into fields and woodlands. Natural streams are channelized when increased runoff from development exceeds
the capacity of the natural drainage features. Pollutants from parking lots. roads, and lawns are washed into streams and lakes by storm water runoff. Who's concerned about the problems?
Increasingly, residents and regulators alike are trying to seek out alternatives to a form of development that has exhibited many shortcomings. Sustainable Development. Smart Growth.
New Urbanism. Traditional Neighborhood Development. and Transit-Oriented Development are some of the initiatives that are being promoted nationally in response to what many view as a
serious concem. State and federal environmental regulatory agencies are imposing strict requirements to improve air quality and threatening sanctions that include withholding transportation
funding to cities that violate Clean Air Standards. Water quality regulations are being expanded to include storm water runoff from small and medium Sized cities in urbanized areas in
addition to the larger cities. which have been regulated for some time. Phase I and Phase II storm water regulations require cities to modify development practices in their jurisdictions
to reduce pollution in runoff from developed areas. What changes need to be made? Principles associated with the various progressive development initiatives and regulations differ somewhat.
but most share a number of guidelines either as central components or peripheral elements. Land and infrastructure should be used efficiently and provide for alternatives to automobile
travel. This generally entails building at higher density (on average) within or adjacent to areas with existing infrastructure. Shops. offices. residences, and schools should be located
near to each other to promote walking. biking, or transit usage. Developments should be designed and oriented to pedestrians. rather than the automobile. Narrower streets, windows or
porches facing the street, sidewalk amenities. landscaping. and detailed building designs all serve to create an inviting. human-scale atmosphere. What about neighborhoods? Residential
developments should include amenities such as open space. parks, natural areas and be designed to promote walking or biking. Environmentally sensitive or valuable features such as streams
and wetlands should be protected and a natural buffer maintained. Removal of mature trees should be minimized and they should be adequately protected during construction. Neighborhoods
should be designed at a human scale with reduced setbacks and narrower streets to encourage interaction between neighbors and make the street pedestrian-friendly. Small. community-oriented
commercial areas that provide services such as groceries. dry cleaning. boutiques, and restaurants should be located within walking or biking distance. • Draft 1 December 18. 2000 
What does the consumer want? Surveys of homebuyer preferences demonstrate widespread support for many of the features outlined. A recent national survey exploring the values of homebuyers
determined that a majority rated the following amenities as "extremely important" Natural, open space 77"10 Walking and biking paths 74% Gardens with native plants 56% Clustered retail
stores 55% Wilderness areas 52% Interesting lillie parks 50% In the commercial arena, new town centers and "lifestyle shopping centers" that feature mixed uses such as hotel, office,
entertainment, retail, and housing are becoming increaSingly popular. Addison Circle in Addison, Legacy Town Center in Plano, and North Richland Hills Town Center in North Richland Hills
are local examples of this new trend in development. Are there advantages for developers? Fortunately, these design techniques offer benefits to developers as well as to residents and
the environment. Developments that incorporate these features will command premium prices and allract buyers. One study found that residents are willing to pay an average premium of
11% to live in neighborhoods that are designed to be walkable and compact, with high quality public spaces and a mix of uses. According to a market researcher, "The amenities that top
the list for every demographic group, such as trails, pocket parks and open spaces, are actually some of the least expensive for a developer to include." Density bonuses offered by cities
in return for land set aside as open space can offset the reduction in area that would have otherwise been built upon, resulting in no net loss or only minimal loss of building lots.
In addition, by constructing more compact neighborhoods with narrower streets and by incorporating other design features, costs for roads and storm drain systems can be reduced substantially.
Take a serious look at the Ten Keys to Developing Naturally and see how they can help you meet your objectives and improve our environment. Naturally North Central Texas is going to
develop develop --so let's do it naturally! Ten Keys to Developing Naturally Key 1: Maintain existing terrain By maintaining the existing terrain of the land to the greatest extent practical,
rather than regrading the property, many objectives are achieved. More of the native vegetation, including stands of mature trees can be preserved. The capacity of soils to infiltrate
storm water is maintained if it is not compacted by construction traffic. Minimizing the area disturbed during construction results in less soil erosion and less sediment entering streams.
Natural drainage systems can be utilized and integrated into the comprehensive storm water management system, helping to maintain predevelopment runoff regimes. Recommendations • Limit
clearing and grading to the minimum required to install Ihe infrastructure • Clear individual building lOis immediately prior to building construction Draft 2 December 18,2000 • 
• Maintain exisling nalural topography and drainage patterns • Preserve and protect as many Irees as possible • Avoid clearing and grading of areas with permeable sOils Key 2: Minimize
impervious surfaces Impervious surfaces are Ihose such as roads. parking lOIS. driveways. and rooftops. thai do not allow any infiltration of storm water into the soil. All rainfall
that lands on impervious surfaces beoomes runoff. which can pick up pollutants on the way to the nearest stream or lake. The extra quantity of water that runs off of impervious surfaces
causes streambank erosion and habitat degradation and can also result in downstream flooding. Excessively wide roads and oversized parking lots also detract from the aesthetic value
of neighborhoods and commercial centers. Wide residential streets result in higher traffic speeds. creating dangerous conflicts between cars and residents. particularly children. Cul-de-sacs
with their large turn around circles generate lots of storm water and reduce the connectivity of of the street network. Reoommendations • Reduce residential street widths • Use cul-de-sacs
sparingly and inoorporatesunken landscaped islands in the rniddle of turnarounds where cul-de-sacs cannot be avoided • Minimize street length by ooncentrating development in least sensitive areas • Reduce parking
lot size by lowering the number of parking spaces and by sharing parking among adjacent businesses • Use pavers or porous pavement in parking overflow areas • Reduce the rooftop area
of buildings by constructing multiple level structures where feasible Key 3: Build in the least sensitive areas Concentrating development in the least environmentally sensitive areas
of the property allows natural areas to maintained as open space. Building at higher density in the portion that is developed can result in minimal loss of building lots oompared to
oonventional subdivision layouts. Consumers are accepting of smaller lot sizes if the development is well designed and open space and recreation amenities (walking and biking trails,
small parks, etc.) are provided. The commonly held areas essentially beoome an extension of the individual lot, beyond what would be affordable by individual homeowners, and without
the headache of maintaining a large lot. Studies indicate that homebuyers will pay a premium for lots adjacent to natural open space, and that such properties appreCiate at higher rates
than those in typical subdivisions. By building in the least sensitive areas, direct impacts from construction activities on ecologically valuable features are avoided. Physical separation
also allows for control of runoff from the completed development in order to minimize impacts, both in terms of the quantity of the runoff and the pollutants carried by the runoff. Areas
that should be preserved include wetlands, floodplains, buffer areas adjacent to streams and lakes, prairies, and stands of mature trees. In addition, areas with highly permeable soils
should be oonsidered for preservation to allow for infiltration of storm water. water. Draft 3 December 18, 2000 
Recommendations: • Conduct an inventory of the property's natural features including streams, wetlands, wooded areas, and soils • Locate homes, buildings, parking lots away from streams,
floodplains, and other ecologically and aesthetically valuable areas • Build at higher density in suitable areas, while preserving sensitive or valuable features as permanent open space
Key 4: Provide open space/parks Natural open space is extremely valuable as wildlife habitat, storm water infiltration areas, and as protective buffers for ecologically sensitive areas.
Just as importantly, open space serves as an extension of the individual residential lot. Natural open space is visually appealing, as it breaks up the endlessly monotonous pattern of
rows and rows of houses. Open space and "pocket" parks provide opportunities for recreation including walking, biking, and bird watching, and play. Common open space and pocket parks
within neighborhoods are particularly appealing to families with children. Younger children can play in playgrounds with other children under the supervision of parents. Parents may
allow older children more freedom to play and explore without direct supervision since trails and open spaces are generally located away from traffic and the frequent presence of neighbors
provides a measure of security. Open space sells. Homebuyer preference surveys show that people want open space and recreation facilities within their neighborhoods. Studies also indicate
that homebuyers will pay a premium for lots adjacent to natural open space, and that such properties appreCiate at higher rates than those in typical subdivisions. Clearly, providing
open space in neighborhoods is a win-win proposition. Open space must be protected from further development in the future by placing a permanent conservation easement on the land. Conservation
easements run with the deed to the property and are held by the city or county or nonprofit organization. The conservation easement must specify that the property is to remain undeveloped
and must also list what activities are permitted. OWnership of open space and parks should be transferred to a homeowner association, a land trust, or the city. The city will also require
that a management plan outlining maintenance activities and responsibilities be submitted and approved as part of the plat approval process. Recommendations • Set aside ecologically
sensitive or aesthetically valuable areas • Protect open space areas through conservation easements or by transferring ownership to the city • Incorporate recreation facilities including
walking and biking trails and playground equipment Key 5: Preserve streams and floodplains Natural streams, floodplains, and riparian buffers are vital to the success of natural systems.
Buffered with trees and vegetation, natural streams provide extremely important aesthetic value Draft 4 December 18, 2000 
to neighborhoods and communities. Natural, undeveloped floodplains provide storage for storm flows, minimizing downstream flooding impacts. Streams, be they natural, tree lined watercourses
or concrete drainage ditches are a major indicator of the character of a community. Maintaining streams and floodplains in their natural condition should be a guiding principle for high
quality development projects, which will in turn influence many of the design decisions that follow. In order to maintain viable natural streams, runoff from developments must be controlled.
Stream channels can be severely degraded by erosion if post-development storm water flows are significantly higher than predevelopment flows. Many of the keys to developing naturally,
including limiting impervious surfaces, providing open space and buffers for infiltration of storm water runoff, maintaining eXisting terrain, and others must be implemented to some
extent H natural streams are to be capable of handling storm flows from developed areas. Recommendations • Conduct hydraulic analyses of streams to determine flow capacity • Maintain
vegetated and wooded riparian buffers along streams (100 feet or more recommended) • Incorporate other keys to developing naturally into project deSigns to attenuate storm water flows
• Locate all structures out of the full build-out 1 00 year-floodplain • Do not place any fill material in the 100-year floodplain Key 6: Direct runoff over vegetated areas Discharging
runoff from roofs, roads, and parking lots into vegetated areas, rather than directly into storm drains offers an opportunity for infiltration of storm water runoff into the ground.
Infiltration of storm water runoff reduces both the quantity of water and the amount of pollutants that would otherwise reach a stream or lake. For the runoff that exceeds the infiltration
capacity of the soil, the vegetation through which the storm water runoff flows can trap and remove suspended pollutants before the flow reaches a water body. There are several ways
in which this can be accomplished. For rooftops, downspouts should be directed onto grassed areas rather than onto driveways or parking lots. Runoff from parking lots should be also
discharged to grassed areas, which are referred to as vegetated filter strips. Filter strips function well when runoff enters and flows across as a "sheef' of water, rather than as a
deeper, fast moving channel of water. Vegetated swales, which are engineered to accomplish both infiltration and filtration of concentrated runoff, can be used in lieu of underground
piping for conveyance of storm water runoff once it collects into a concentrated flow of water. Landscaped and vegetated areas, particularly in commercial and multi-family residential
settings, also provide an attractive visual buffer to break up the monotonous pattern of buildings and parking lots. Significant areas of grass, trees, and shrubs also serve to reduce
temperatures compared to vast expanses of asphalt and concrete under the hot Texas sun. With proper design, and accompanied by other design considerations such as reducing overall impervious
surface. etc., vegetated filter strips and vegetated swales can reduce storm drain infrastructure costs as well. Draft 5 December 18, 2000 
Recommendations • Direct roof drains onto vegetated areas rather than driveways or parking lots • Discharge runoff from parking lots as sheet flow into vegetated filter strips bordering
the lot • Incorporate depressed, vegetated areas within parking lots, rather than raised landscaped areas to allow runoff to infiltrate • Use open drainage (vegetated swales) where feasible
instead of underground storm drain systems Key 7: Use native and adapted plants Landscaped areas, with all of their benefits, can also contribute to the pollution of streams and lakes
if they are not managed properly. The use of plants that are not well suited to the climate and conditions in North Texas can result in the need for frequent use of pestiCides and fertilizer
to maintain the plants in a healthy condition. What's good for the plants, however, can be damaging to the environment and to human health as well. The application of insecticides ends
up killing not only the "bad" insects, but also the beneficial ones, such as bees, butterflies, and earthworms. Anything eating the poisoned insects such as amphibians, lizards, birds
and mammals will also ingest these toxins. In addition, pesticides applied to landscape plants and lawns can be washed into water bodies by storm water runoff, where impacts to aquatic
life can occur. Pesticides also present a possible health risk to humans, particularly to children who might play on recently treated lawns. Fertilizer causes problems as well when it
runs off of lawns and landscaped areas and into local waterweys. The extra nutrients may cause aquatic plants (including algae) to experience rapid growth. Under the right conditions,
these plant and algae "blooms" can reduce oxygen levels in the water and kill fish. Another consideration is that landscaped areas must be covered, either with plants or with mulch in
order to prevent soil erosion. Sediment washed into waterweys is a form of pollution that needs to be controlled. The use of native plants, and those that have been adapted to the local
climate and conditions, save money by redUCing the amount of water, pesticides, and fertilizer that must be applied to keep the plants healthy. Recommendations • Use native and adapted
plants for their natural resistance to pests and drought tolerance • Reduce the usa of pesticides, fertilizer, and water for irrigation • Maintain vegetated areas in good condition to
reduce soil erosion Key 8: Consider ways to reduce car travel Automobiles impact the environment in a number of ways, both directly and indirectly. Most people are aware that automobiles
are a major source of air pollution. In the DFW region, car exhaust accounts for almost one-half of the chemicals that contribute to the creation of ozone in the lower atmosphere. Ozone
pollution causes a number of health problems including respiratory system irritation, inflammation and damage to the lining of the lungs, and increased asthma attacks. As population
in the region increases, more cars on the road, more congestion, and longer commutes will lead to more air pollution and more health problems as a result. Draft 6 December 18, 2000 
Many are unaware however, that cars are a significant contributor of pollutants that can negatively impact water quality. Petroleum products including gasoline, oil, and grease drip
from cars onto roads and parking lots and are then carried into waterways by storm water runoff. Metals such as zinc, lead, copper, cadmium, copper, chromium, and nickel are also used
in various car parts that are deposited on roads and parking lots as the parts wear. Indirectly, automobiles contribute to damage of the environment as a result of the sheer magnitude
of impervious surfaces that are required for the operation and parking of vehicles. Roads, parking lots, and driveways generate a tremendous amount of runoff that threatens the equilibrium
of natural streams. If runoff from impervious surfaces is not managed properly, natural channels will be overloaded by storm water runoff, requiring that they be converted to concrete
drainageways. The most effective option for reducing the impact on streams is to minimize impervious surfaces, rather than just attempt to manage the runoff by the use of expensive control
measures such as retention or detention ponds. In order to reduce the need for more highways, wider streets, and expansive parking lots, alternative to automobile travel must become
more feasible for travelers. Incorporating walking and biking trails that feed into a broader network of bicycle and pedestrian transportation facilities is one way to provide alternatives
to car use. Other design options are also effective in reducing automobile travel. Locating concentrated developments near transit facilities gives residents the option to use public
transportation rather than their personal vehicle for trips to work, shop, etc. Designing mixed-use developments in which residences, shops, and schools are in close proximity promotes
walking to the nearby corner store, restaurant or school. In addition to the water quality benefits, altematives that reduce automobile travel will result in less vehicle emissions.
All of these these options serve to reduce the vast and expensive infrastructure required to support automobile travel and will result in improvements in air and water quality and corresponding
benefits for human health. As is the case with many of the keys to developing naturally, the principles outlined here are popular with homebuyers. Homebuyer preference surveys demonstrate
there is a strong desire among consumers for walking and biking trails and clustered retail stores in neighborhoods. Everyone wins when developments and transportation systems are designed
to meet the needs of people first and automobiles are given secondary consideration. Recommendations • Provide walking and biking trails in neighborhoods • Design and build mixed-use
developments that incorporate residential and commercial areas that are within walking or biking distance of each other • Develop near transit lines/facllities • Develop at sufficient
density to support practical transit usage Key 9: Incorporate detention/retention controls There have been a number of changes in the way in which storm water runoff from developed areas
is managed. The traditional approach has been to develop with little regard for storm water other than to construct drainage systems that move the water off the site as quickly as possible.
More recently, devices have been used (to varying degrees in different parts of the Draft 7 December 18, 2000 
country) for controlling the rate of flow and timing of storm water leaving the site, and in some cases to reduce the amount of pollutants in the runoff as well. These controls generally
work by capturing and holding a portion of the runoff and then releasing it slowly over a sufficient period of time to reduce the "peak" flow from the site. As mentioned, the controls
are sometimes designed to hold the runoff long enough to permit settling out of some of the pollutants so that water quality is improved at the same time. Detention controls, or dry
detention ponds, fill up during storms, but they discharge completely and are dry during the periods between storms. Dry ponds have grassed bottoms, and with proper maintenance, can
be used for recreation when they are dry. Retention controls are known as wet ponds since they maintain a permanent pool of water between storms. The banks and outlet of a wet pond is
constructed to provide for storage and subsequent slow release of storm water runoff. Wet ponds look much like any other pond and with careful attention to design and to maintenance,
they can serve as an attractive water feature in residential and commercial developments. Detention and retention controls should ba considered only after all other keys for developing
naturally have been explored and implemented to the greatest extent possible. In many cases, the need for these "treatment" or "structural" controls as they are sometimes referred to
can be avoided altogether, or they can be reduced in size if the amount of runoff and entrained pollutants are minimized by the design of the project. Generally, it is cheaper and more
effective to implement deSign elements that prevent or reduce the generation of storm water runoff and/or pollutants at the source. However, should factors beyond the control of the
developer preclude the full use of other Keys, detention/retention controls shOUld be incorporated into the project. Recommendations • Incorporate the other Keys to developing naturally
to the greatest extent extent possible • Evaluate the need for retention/detention controls based on inclusion of other design elements for reducing storm water impacts • Integrate retention/detentio
n controls in a manner that they function as amenities Key 10: Use slotted grates to remove trash Trash that ends up in streams and lakes is more than an eyesore, it can affect water
utilities, residents, and wildlife. Removal of trash and debris is time consuming and expensive for local governments once it is in the waterway. Prevention is the preferable approach
to litter control. In commercial areas, slotted grates can be very effective in preventing trash and debris from entering the storm drain system and being discharged into streams and
lakes. More advanced storm drain inserts can also trap oil, grease, and grit. These devices are appropriate for high volume parking lots and businesses such as gas stations, car washes,
or automobile service garages. Generally, grates or inserts are not appropriate for use in residential areas (except perhaps apartments) because of the lack of an on-site maintenance
staff. Recommendations • Place slotted grates in storm drain inlets in commercial areas to capture trash and debris Draft 8 December 18, 2000 
• Use storm drain inserts (oil and grit separators) in areas where large amounts of oil and grit can be expected (parking lots with heavy automobile traffic. gas stations, service stations,
etc.) • Ensure that the facility owner is aware of maintenance requirements For more information: ! Organization Internet Address I North Central Texas Council of Governments www.dfwstormwater.com
I Publications Availability Keys I Storm Water Quality Best ManagementIPractices for Residential and Commercial Land Uses in North Central Texas July 1993 Ordering information at htt!;!:lIdfwstormwat
er .com 6,9,10 I I Texas SmartScape CD (Same as above) 7 I I I I I Organization Internet Address , Low-Impact Development Center htto:lliowimoactdevelooment.oro Publications Availability
, Keys I , Low-Impact Development Design Strategies: Downloadable in pdf format 1,2,5,6,9 ,IAn Integrated Design Approach, Prince I !George's County, Maryland, June 1999 IOrganization
Internet Address , Center for Watershed Protection WWW.CWD.oro Publications Availability Keys Better Site Design: A Handbook for Changing Ordering information at : 1, 2, 3, 4, 5, Development
Rules in Your Community I organization web site 6,8,9 (August 1998) Nutrient Loading 'rom Conventional and Ordering information at 2,3,4,5,6, ! Innovative Site Develoement, July 1998
organization web site 9 Organization Internet Address , Maryland Department of the Environment www.mde.state.md.us Publications Availability Keys 2000 Maryland Stormwater Design Manual:
Downloadable in pdf format Volumes I & 1/1, 2, 3, 4, 5, I 6,8,9 Organization Internet Address New Urban News www.newurbannews.com Publications Availability Keys I The New Urbanism and
Traditional Ordering information at 2,3,4,5,8 , I Neighborhood Development: Comprehensive Iorganization web site I IReport and Best Practices Guide New Urban News Magazine ' Ordering
information at , 2, 3, 4, 5, 8 J organization web site Draft 9 December 18, 2000 
: Organization Internet Address I . Smart Growth America www.smartorowthamerica.com Publications Availability I Keys I 􀁾􀁇􀁟􀁮􀁟􀁥􀁟􀁥􀁟􀁴􀁩􀁮􀁟􀁧􀁟􀁳􀁟􀁭􀁟􀁯􀁟􀁭􀁟􀁳􀁟􀁭􀁟􀁡􀁟􀁲􀁴􀁟􀁇􀁟􀁮􀁟􀁯􀁟􀁷􀁴
􀁟􀁨􀁟􀁁􀁟􀁭􀁟􀁥􀁮􀁟􀀧􀁣􀁡___-LD_o_w_n_lo_a_d_a_b_le_i_n_p_df_f_o_rm_a_t___􀀡􀀬􀀮􀁾􀀧􀀠2, 3, 4, 5, I rprganization Nonpoint Education for Municipal Officials Internet Address www.canr.uconn.edufcesfn
emo Publications Numerous free and low-cost brochures : alternative site desian on Availability Ordering information organization web site at Keys Various I I • Organization Internet
Address American Plannin!:) Association www.olannino.oro Publications Availability Keys I i Best Development Practices, Reid Ewing, Ordering information at IVarious I APA Planners Press,
1996. www.plannina.orafbookstore . ! The Principles of Smart Development, 1998 Ordering information at 1, 2, 3, 4, 5, ! www.olannina.orcr/bookstore . 6,8,9 ,conservation Design for Subdivisions:
A Ordering information at 􀁾􀀠1, 2, 3, 4, 5, ,Practical Guide to Creating Open Space' www.planning.org/bookstore 6,8,9 , Networks, Randall Arendt 1996 The Next American Metropolis: Ecology,
Ordering information at 2, 3, 4, 5, 8 Community. and the American Dream, Peter' www.planning.org/bookstore Caltha e, 1993. Web Document Texas Non oint Source Book ,IOrganization Internet
Address IAtlanta Regional Commission www.atlant§[egional.comfdesign . manual IPublications Availability Keys Downloadable in pdf format 1,2,3,4,5,IGeorgia Stormwater Management Design
Manual, Draft, May 2000. 6, e, 9 Draft 10 December 18, 2000 
In cooperation with the North Central Texas Council of Governments Municipal Stormwater Monitoring Program, 􀁄􀁡􀁬􀁬􀁡􀁳􀁾􀀠Fort Worth Area, Texas-Summary of Sampling, February 1997-February
2000 ,l... __L LOCATION MAP Di!'ibl bJ..'ll: from U$ Geu1u:;i;;;l1 􀁓􀁕􀀮􀁦􀁜􀀧􀁾􀁹􀀠EXPLANATION SCil!\\ L2.000,ooo Albtr; 􀁉􀀺􀁱􀁭􀁬􀁬􀀭􀀡􀁬􀁦􀁾􀁡􀀠􀁰􀁲􀁵􀁪􀁾􀁣􀀨􀁩􀁑􀁮􀀠􀁢􀀺􀁬􀁾􀁾􀁤􀀠011
PREDOMINANT LAND USE 􀁓􀁪􀀻􀁭􀀼􀁦􀀻􀀡􀀡􀁾􀀠p:u;:!kb 45.5 illUl 29.5 􀁴􀁫􀁧􀁦􀁬􀀺􀀢􀁾􀀠REACTIVATED DISCONTINUED NEW SITES SITES SITES '0 Industria! 16. Residential 31.... Mixed 3. Residentinl
17. Commercial 35. Undeveloped 40 190Hie<hwav Industrial 5. " . Site numbers 20Commercial 0 Highway referenced in table 1 Figure 1. location of study area and stormwater monitoring sites.
!Il IS MiLES 􀁟􀁾􀁉__-11 During 1992-94, the U.S. Geological Survey (USGS), in cooperation with the Norlh Central Texas Council of Govcmments (NCTCOG) collected stormwater runoff data
for the cities and Texas Depru1ment of Transportation (TxDOT) Districts in the Dallas-Fort WOl1h (DFW) area to meet the regulatory requirements of the application phase for the National
Pollutant Discharge Elimination System (NPDES) stormw.ter permit The Phase I permit requirements applied to cities with populations of 100,000 or greater and to TxDOT districts with
popUlation centers of 100,000 or greater (U.S. Environmental Protection Agency, 1990). The foHowing cities and districts in the DFW area met the population criteria: Arlington, Dallas,
Fort Worth, Garland, Irving, Mesquite, Plano, T"DOT Dallas District, and TxDOT Fort Worth District-The permit applications were submitted tl) the U.S. Environmental Proteetion Agency
(EPA) for approvaL Beginning in 1997. the approved stormwater discharge permits were issued to the seven cities and two T,DOT districts that required a permit-compliance phase with additional
sampling for a 5-year period. In 1997, the USGS began a study in cooperation with the NCfCOG to coHect stormwater samples mid characterize stormwater runoff for the seven cities and
two TxDOT districts for the period 1997-200L At the end of the 5-year permit-compliance phase, the EPA wi[[ transfer the stonnwater discharge permits to the Texas Natural Resource Conservation
Commission for U.S. Department ot the Interior 9' USGS Fact Sheet 042-00 U.S. Geologtcal Survey November 2000 
A. Equipment shelter and solar panel for undeveloped site in Plano, Tex.; the rain gage is mounted just above the solar panel. renewal. The USGS, during an ongoing study, will analyze
the data collected during the 􀁰􀁥􀁮􀁮􀁩􀁬􀁾􀁣􀁯􀁭􀁰􀁬􀁩􀁡􀁮􀁣􀁥􀀠phase and recommend possible changes to the network design and sampling schedule. This fact sheet describes the monitoring
nelwork and sampling schedule during the permit-application phase and the 5-year permit-compliance phase (1997-200 l) and summarizes the sampling during February 1997-February 2000.
Description of Study Area The DFW area is located in north-central Texas ftig. I), and the J. 􀀷􀀰􀀰􀀭􀁳􀁱􀁵􀁡􀁲􀁾􀀭􀁬􀁬􀀱􀁩􀁬􀁥􀀠urca lies within Collin. Dallas, Denton. and Tarranl
Counties.. The DFW area is in the upper Trinity River Basin with three major tributaries oftlle Trinity River draining the area-West Fork Trinity River, Elm Fork Trinily River, and East
Fork Trinity River. Mean annual precipitation in the study area varies from abollt 31 inches in Tarranl County to 36 inches in DHIIns CO"llly, with the months ofApril and Mny typically
the wettest nnd th" months of July and August the driest (Ramos, 1999). Monitoring Sites During the permit-application philse, 30 monitoring sites were estabHshed during t992-93 in small
(160 􀁬􀁉􀁣􀁲􀁣􀁾􀀠01" less) drainage basins. each categorized by a single predominant land usc (11 􀁲􀁥􀁾􀂭IdentiaL 9 industrial, 6 commercial, and 4 highway). Five sites each were
located in [he cities of Dallas and FOli 'North, four in Arlington, three each ill Garland, Irving. Mesquite. and Plano, and two siles eaeh in TxDaT Dallas and TxDOT Fort Wot1h. Pifteen
of the originl.l130 monitoring sites (I-IS, table I) were reactivnted in (997 for the p\!rmil-Compliance phase, including 4 residential, 4 industrial. 4 cOBHuercial. and 3 highway_ Three
siles each are located in Dallas and Fort Worth, two sites each in Arlington and TxDOT Dallas, ;md one site each in Garland, 􀀨􀁲􀁶􀁩􀁮􀁧􀁾􀀠Mesquite. B, Inside an equipment shelter.
Plano, and TxDOT Fort WortlL The remaining IS siles were discontinued (16-30, tuble I). Seven new sites (31-37, tilble I) were established during 1997-98 for the permit-compliance phase.
One site is located in each of the seven cities: no new TxDOT sites were established. Six of the new sites are located in drainage basins with mixed land use, and one site is located
in an undeveloped drainage basin. Three of the six sites with mixed land lise are located at outfalls wirh drainage areas less than 500 acres. and the remaining tht"CC sites me locnted
instream with drainage areas of at least 2,500 acre:;; (table I). Most of the monitoring sites are located <It storm sewer outfalls or concrete-lined open channels. Two siles are located
at natura! channels. Each site houses the monitoring equipment in a shelter (photo A). A rain gage and solar panel are attached to the sheltcl". fn::.ide the shcJter (photo B) are an
automatic sampler, a peristaltic pump. a datalogger, and a gas bubbler systern. The stage of the water in a culvelt or open channel is measured using a pressure transducer and a gas
bubbler system that regulates the periodic rcleas..:: of a bubble of carbon dioxide through an orifice line below tl1..:: water surface. The pressure transducer measures the pressure
required to force the bubble out of the oril1oe line and converts the pressure to the stage of the 􀁷􀁾􀁉􀁴􀁥􀁲􀀬􀀠in feet. The stage then is used to compute the instantaneous discharge
Llsing a different equation specific for a 􀁦􀀱􀁬􀀱􀁭􀁥􀁾􀀠opcn channel, or weir. The datalogger computes discharge, accumulates the volume of runoff, and stores information, Stich as
date, time. precipitalion, stage. discharge, volume, and number of samples caHected. The equipment is pO\vered by a 􀀱􀀲􀁾􀁶􀁯􀁬􀁬􀀠baltery maintained by the solar pl.loel. A telephone
tine and a modem arc installt':d at each sHe (0 provide lelen'lelry to communicate with cach site renlOtely to monitor a storm event. dmvnload data, modify progrmn parameters, enable
or disable the automatic sampler, and notify personnel of a storm event Sample Collection and Analysis Two conditions are required for sample collection: (1) Antecedent dty wCilther
conditions (no more than 0.1 inch of precipitation in a 24-hour period) should occur for the 72 hours prior to the storm event to allow for accumulation of possibk contaminants. 
9 Table 1. NPDES municjpal stormwater Sl'lt;:l$ in the Dallas-Fo(t Worth area and summary of sampling, Febiusry i997-February 2000 !Siles i-15 ".-;!:lbrlsll"I1I1)92-'X' during p..:nn'II-;tflplkativu
􀁰􀁨􀁬􀁬􀁾􀁃􀀺􀀠:;1["... It-;lU ,,:.tablish:u 1'J:l2-·YJ UI'(j'llt p..-rml;-'Jrpli<.:atitln pht:,.e :mJ dh...::>u\imh.'<.i 1")')7-,):' Juring 􀁰􀁾􀁲􀁭􀁪􀁨􀀧􀁯􀁈􀀺􀁰􀁬􀁩􀁡􀁬􀁬􀁣􀁥􀀠pha",:;
sites 31-37 􀁜􀀻􀀮􀁾􀁕􀁬􀁨􀁨􀁳􀁨􀁤􀀠!1}\}7-I)R ..lumg permit->':(lmplian..", pl-mSl!. USGs, ;Ls. 􀁇􀁥􀁤􀁈􀁬􀁾􀁩􀁾􀁤􀀠511".0:: T.\DOT, Tex.\,> [).;::parlm':nl (lfTransptlntt:innl Site
USGS PredQmi-Drainag;;City or no, stai!on Sta1lon name nant land area Collected ScheduledT:<DOT distrlct (109,1) no, use (acres) '1992-94 1997-2001 Feb. 1997Rgactivated sites 􀁭􀀺􀁡􀀩􀁊􀁾􀀵􀀰􀀺􀀧􀁩􀀠
Pjlon :ill\",:'1 Outfall a: \kldmm Rd. Ft'r1 Wtirlh 􀁨􀁬􀁤􀁾􀀡􀁓􀁬􀁤􀀻􀁪􀁪􀀠15! l»l(MS5·1:'i Dr) 3f:!m:hOulr:Jliu[J3dSL fun \Vonh Imlu,.trial 73.7 ,J OatWnOO F::U"\,"fll Hill--. Hi1!ll
S<:hool OlltfaU at Wdlcf Dr. for! WUll!> R,,':>iilcnli,lJ 151 ,, 0S04Sl)1H Do:<:[ C!\'vf,., OUlfa!l illl..},:5W T;.;DOTFort W,lIlh Highw.j), 􀀨􀁪􀀢􀁾􀀬􀀠I 5 080·:J911U TIt,! Parh i\1'11l
OIMall:1I !-J(}W Allillgtnl! C(lmU1<!rciaj :'S.ll 1 6 OSO-l932U Riv,:r LO:f'ac), P;lfk OutfJlI ;,)! Gr":':ll 􀁏􀁡􀁫􀁾􀀠Blvd. Arliug[OlI 􀁒􀁾􀁳􀁩􀁤􀁴􀀡􀁬􀀡􀁬􀁩􀀺􀀱􀀱􀀠160 7 7 I»lO-l9S90
B<-<,l! 􀀨􀀢􀁬􀁜􀀧􀀢􀁾􀀧􀁦􀀬􀀮􀀬􀀠OutEdl tlt ShaLly Gru\-,: Rd. Ir"ing 􀁒􀁾􀁳􀁩􀁵􀁲􀀺􀁬􀁬􀁬􀁬􀀻􀁬􀁬􀀠(>5.3 reb. 2000 lIJ lIJ 'I) W lO 8 08049860 i\'I<)lIH!:lin 􀁃􀁉􀁾􀁶􀁫􀀠Oulrall ,111-10
:-xDOT 􀁄􀁡􀁬􀁪􀁴􀁬􀁾􀀠Highw:I)' 115 7 [J 9 9 00055690 l311dltll411l Br..ute!! Oulf;!11 a[ 1-635 T.\DOT Datla:Higlnvay 7 u 10 00056390 l3aslilll! $lf<:<::'( Ollifall at 1...\ R.!'unio!1
Pk.",,),. D,tlLt-'< Inull"lri.d 49.5 7 o" II OW57U5 Whilo: Rn<:k Cr.:.:k. Ou((all al rn,'i(\lf1 RlI. 􀁄􀁾􀁬􀁬􀁬􀀺􀁩􀀮􀀧􀁜􀀠C()II\IIk:fc:illi 59.1 7 OJ '" 9 11 U8057:+41 N,,:wion Ct'.;..:f,.,
Oulr:111 al'I1!,f';! S1. 􀁬􀁽􀀮􀁤􀁬􀀻􀁬􀁾􀀠􀁒􀁌􀀧􀁾􀁩􀀨􀁫􀁬􀁬􀁬􀁭􀁬􀀠7 13 13 OS061525 Sprlllg Cf':'"1.; O,ul":l11 al P;lrk BlYLl. Plano Commcrcial 7 D '" " OS{l61635 Tribulary In Dttck
Cll'l'k OUllaH a( HlghllA>;N' Rd. G.llbnd Indm.1r!al .'13.9 7 J.\ II) 15 OS061910 Soulh 􀁬􀁜􀀡􀁣􀁳􀁱􀁜􀀡􀁩􀁬􀁾􀀠((I."\.'k o,tlr,111 ill 1-635 I\lcsquili' CUHlIlk'r;:iJII jJ 8 Discontinued
sUes ()8()47H}O Ch.::tr Fork Trinily Riw.Oullilll ai Oak Hill Cr. Pm'! \\bnll Residentml (11,7 7 17 OSO.lS510 Wl'''! Fork Trinily Riwr Outfall al Highway 131 Fort WOIlh 􀁃􀀨􀁬􀁬􀁬􀁬􀁮􀁴􀁥􀁲􀁾􀀧􀁩􀁡􀁪
􀀠[", 7 1& OSU49360 Trihu!m-;: (I> 􀁗􀁣􀀮􀁾􀀨􀀠Fark Tnnity RiwrOulfill! all3ainJ';; Hum R<1 Ar!ingllJll RI.":7.idcllli<11 77.1) 7 ,9 {)SQ..l.<).I70 Tribu!ary to lohu!IDll Cr..􀀧􀀧􀀺􀁾􀀠Oulr;dl
􀀺􀁴􀁬􀁬􀁾􀀳􀁴􀁩􀀠􀁅􀁡􀀮􀁾􀀨􀀠􀀯􀁜􀁲􀀡􀁩􀁮􀁾􀁬􀁵􀁮􀀠int.laslri<1! l'!5.5 :10 OSO--tt)9'5(j 􀁉􀀧􀁩􀁾􀁨􀀠Crl!l'k Olltfi!ll:« 1-20 T.\DOT Foo Wonh Highway ·W.Y 7 0&).55570 [·[.:orl."lol"u
Rd. Ou!fal! a( W;llnul Hill Ln.. Irving Indlililrial .l3A 7" osn55:wo J(}...􀁾􀀠Cr<".;k Out!":J!!:1I o..'lI{(>1l Dr. D.dla.." Indu.,[ria\ 9.0 7 ilS056HlO Tril,;\I!ury (tl Elm Fork Trillit1
Ri\"l."r(h!\fall at C::l:-K'ade 51. In··jug tndu:;,ri:!1 ·t',9 7 ilS057310 􀀺􀁜􀁾􀁨􀀠Cruf,., OU!!;I!! m 􀁗􀁨􀁬􀁬􀁬􀁩􀁾􀀧􀁲􀀠51. D"J.!l'ltl Residcntial 11.3 7 0;;061 j 10 R(1Wl¢u Cr.."k
Oall,l!! at \\'1110;11" Cr......·k Park Plallo R .. 􀁾􀁩􀁤􀀭􀀢􀁮􀁬􀁢􀁬􀀠51..l 7 􀁜􀁽􀀮􀁾􀀩􀀶􀀡􀀳􀀳􀁮􀀠Spl'inl;! CrL'cf,., Outfall 31 A\·I."IIlH! F PlmKl Im.lu;;lnill ·Hi.\! I O:-;0616tiO
5b'PY Hi.lI{)w St. OU1(a!l:lt :-./unhwl.";;t !!iglnmy G;,jrl;md Re_,i,kmi:iI ()7.3 7 nt<.I16l6t)1.l 1-6350011,111 ,II c".II.!n·i!k Rd G.ll"llmd COHlmcrcial .16.:! 7 OR06!9Ij South ;\j,"'luil'"
Crl."c'k Oulf;]!! lit Soulh 􀁐􀁡􀁲􀁾􀁉􀁉􀀧􀀼􀀱􀀩􀀧􀀠􀀬􀁜􀀱􀀮􀀺􀁾􀁱􀁵􀁩􀁬􀀻􀀺􀀠RcsiLlellli;]1 -15.-1 7 30 uSn619·10 Smuh 􀁦􀀾􀁫􀀢􀁉􀁕􀁩􀁬􀁾􀀠􀁃􀁲􀁾􀀢􀁥􀁫􀀠OlJlf:.'.i1 l.!l arm,ln Rd.
􀁾􀁫􀁳􀁻􀁉􀁕􀁩􀁬􀁾􀀧􀀠􀁒􀀻􀀡􀁾􀁩􀁤􀀺􀁣􀁮􀁬􀁨􀀡􀁬􀀠·U\2 7 New slles 3' '6 􀁜􀁾􀀧􀁻􀁕􀀴􀁬􀀺􀁴􀁩􀀭􀁬􀁝􀀠S;Yl."ll!llilfl' 􀁃􀁲􀁾􀂷􀁾􀀱􀀮􀀠ill 51."0U Aw. filft Wo(1I1 ?Ii;v,,,>il :! 1.760
OSO-l9:!4ti Rtf". ('r....do, ;I[ WlwJllIni.l Pnri Hln!. Arlington Mi,;;:d 17.U14 01{055:'1jll Cmhlllwofl<.l Br.mt:h Trihul:lfY OUli:OUli:11l :11 Sf..y Cir. Ir..·ing 􀁾􀁨􀁸􀁥􀁤􀀠I􀁾􀀷􀀮􀀷􀀠();.;05u,IS
U Knighb Br.IUdl TribU[;IQ·.1I CeJatSvrings Rd. D,dla.., "'[[xcd -IS6-1 (*lUfJI515 RL';,:k Br;!II.:h 􀁏􀁵􀁬􀁲􀁾􀀱􀀱􀀱􀀠al Wyll1,!ln.: ilh'tl. Pi;!II(l Urnkvdop.:Ll 70A 30 !;''{0615..J.1
J','1ilb SWII..:!. Triblll:1l1' a\ t\, Filib Sl. ],..!i:-o..-,J 1('iS.S 􀁟􀁾􀀩􀁾􀀷􀁟􀀭􀀬􀁩􀁾􀀢􀁾􀀧􀁩􀀾􀀶􀀺􀁣􀀺􀀻􀀧􀀢􀁾􀀧􀀺􀁩􀀺􀀺􀀬􀁏􀀠NOl'lh /!.\..;....quill' Cn"d. ilt 6dd.n..: Rd_
l\Ii;v...'ti 2 . .100 L'! III 6 9 13 " (2) ll1C total storm precipitation should range between 0.2 and I <5 inches (Baldys and othel"" 1998)< During the permit-application 􀁰􀁨􀁡􀁳􀁥􀁾􀀠seven
samples were collected at each of the 30 ,ites and analyzed lor 188 selected properties and constituents (Btlldys anti others, 1997). Durin.g the 5-year permit-compliance phase, the
13 samples seheduled for the 15 reactivated sites and th(; 24 s<lIllples scheduled for the 7 new sites will be ana)yzed for a reduced list of 23 required properties and constilUents.
The permit-c{)lnpliance sampling schedule is divided into 6'nlonth periods (Seplember-February and March-August), during which a predetermined number of samples are to be collected.
For the reactivate{) sites. five samples were scheduled in the first year (two sUluplcs in the 􀁮􀁮􀁾􀁴􀀠6-month period and three samples in the next period) and two sall1ples per year
(one in each 6-monlll period) for the following 4 ye..1fS. For the new site.<.;. six samples pcr year (three in each 6-month period) are scheduled for the last 4 year" of the 5-ycar
period, Table I list" the number of samples scheduled for the permit-compliance period and lhe nUIHber of samples actually collected during February 1997-Fcbfuary 2000. Some samples
were not collected as scheduled because of extended periods of tittle or no precipitation. Two types of sal11[1les arc collected [or analysis of walet'quality properties and conslHucnts.
Grab samples are coUecred manually, and composite sample.'i are collected by the automatic sampler. The samples are analyzed for sekcted properties and constituents in accordance wilh
guidelines sct by EPA (U.S. 􀁅􀁮􀁶􀁩􀁾􀀠ronmcntal Protedion Agency, )992). Figure 2 shows nn example of the aCCUl1lul"lted precipitation. the discharge, and the times of the grab and
composite aliquot samples for (J storm sampled 011 May 15, 1997. at site 08056390 Bastille Street Outfall at La Reunion Parkway, Dall",. Texas, 3 
0.8 Accumulated ptecipBalion 90 00 w Discharge [50.7 􀁾􀀠Composite sample ;;;; z \ Grab sample ,;'0.6 o t 􀁾􀀠\I-0.5 .n: d \5 .u IIg: 0.4 Ii /I @􀁾􀀠0,3 /1=> , I => " 􀁾􀁏􀀮􀀲􀀠. /J
0,1 /I 􀁾􀀠􀁾􀁸􀀬􀁾􀀭􀁾􀀭􀁾􀀠􀁾􀀠10 􀀮􀀭􀀮􀁕􀁾􀀯**f---􀁟􀁾􀁟􀁾__􀁾􀀧􀀠􀀧􀀭􀀬􀁟􀁾􀀽􀀽􀀽􀀽􀀽􀀺􀀲􀀢􀀧􀁾􀀧􀀽􀀽􀁾􀁏o 1015 103b 1045 1100 1115 1130 1145 1200 1215 1230 1245 1300 1315 1330
'5 May 1997 Figure 2. Hydrograph showing accumulated precipitation, discharge, and times of composite-and grab-sample collection at 08056390 Bastille Street Outfall at La Reunion Parkway,
Dallas, Texas, May 15, 1997. The grab sample typicaHy is collected during the first 2 hours of a stonn to catch the I1rst flush of the basin-.the initial slorm\v,alel' runoff that often
contains aCCllllllllations of possible cOnlatlJ,inants. The grab sample is analyzed for fecal coliform bacteria, fecal streptococcus bacteria, oil and grease, phenols ([xDOT Dallas only).
(tlld licld properties. The tield 􀁰􀁲􀁯􀁰􀁥􀀧􀁴􀁩􀁥􀁳􀀬􀁾􀀠specific conductance. pH, and water temperature-are measured at the time of samp[e collection. The composite sample is a cOI'nbinutton
or discharge-weighted sample aliquots collected throughout a storm by the automatic sampler programmed to (;otlecl discrete samples after a 􀁳􀁩􀁬􀁃􀁾􀀠spccific pre-specified volume
of discharge has passed the site. The composite sample is analyzed for biochemical oxygen demand. chemical oxygen demand. suspended solids. dissolved solids. ammonia plus organic nitrogen.
nitrite p!us nitrate 􀁮􀁩􀁴􀁲􀁯􀁾􀀠gen, lotal phosphorous, dissolved phosphorous, arsenic, cadmium, chromium, copper, lead, nickel (TxDOT Dallas only), zinc, and diuzinon, Data Analysis
and Use The concentratioll data compiled by the monitoring program arc used pdmarily for pennlt compliance to characterize the stormwater runoff in the DFW area. The evenHncan concentrati.on
data can be used to (1) characterize stormwalcr runoff, both for individual land uses and for the entire DRV area: (2) estimate storm loads and mean HI1Hual loads for selected constituents
to receiving waters: and (3) provide policy makers with information to develop effective management practices. These data also are useful for comparison and analysis in other parts of
the state and country_ References Baldys. Stunley, Ill, Raines, TH., lVIanstleld, B,L., and Sandlin, l.T.. 1997, Hydrologic data for the urban stormwater studies in lhe Dallas-Forl \Vorth
<:It'0a, Texas. 1992-94: U.S. Geological Survey Open-File Report 96482. 256 p. ,_1998. Urban stonnwater quality, event-mean 􀁣􀁯􀁮􀁣􀁥􀁮􀁬􀁲􀁡􀁾􀀠tions. and estimates of stofflw.:atcr
pollutant loads, DallasForI Worth area, Texas. 1992,,93: U.S, 􀁇􀁥􀁯􀁬􀁯􀁧􀁩􀁾􀁡􀁬􀀠Survey Water..Rcsources Investigations Report 􀀹􀀸􀁾158, 5 [ p. Ramos. lVI,G" ed., 1999,2000-200 I
Te,"s almanac: The Dallas Morning News, 672 p. U,S. Environmental Protection 􀁁􀁧􀁥􀁭􀀮􀀺􀁹􀁾􀀠1990, National Pollutant Discharge Elimination System permit applkntion regulations tor
storm water discharges-Final rule: U.S, Federal Register. ",55, no. 222, p, 47.989-48,09[, __1992, Nationn( Pollutant Discharge Elimination System stOrlll\vater sampling guidance document:
U_S_ Environmental Pmtection Agency, 121 p, 􀁾􀁓􀁴􀁥􀁦􀁊􀁬􀁵􀁕􀁬􀁩􀀨􀀡􀀠j, Moo}'e. Timothy H. Railles, and Stanley Baldys [[I Any use 􀀨􀁾􀁦trade, prodUCE. orfinlllwmes is}or descrilJlil'e
JW1])oses ollly (//1(/does nol imply endorsemelU by the U.S. Gm'clw/U!jj{. 􀀭􀁾􀀬􀀭􀀭􀀭􀀭Information on technical reports and hydrologic data related to this study can be obtained from:
Fort Worth Subdistrict Chief Phone: (817) 263-9545 U.S. Geological Survey FAX: (817) 361-0459 Fort Wonh -Field Headquarters World Wide Web: 2775 Alla Mesa Blvd, hltp:lltx.usgs.gov/Fort
Worth, TX 76133 'c u.s. 􀁇􀁏􀁖􀁴􀁾􀀧􀁬􀁍􀁅􀁎􀁔􀀠PRINTiNG OfFICE; 2GOO _ f>/l-D89 /<;2021 Rtlqiun No. B