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Chapter 3. Controlling Urban Runoff 3-110 

1 4 . Urban Runoff Management for the Redevelopment Sector 

3. 

2 The implementation measures listed in Section 2 for reducing runoff 

3 volume are expanded in this section because4.1 Introduction

4 It has been estimated that about 50 percent of the importance of addressing redevelopment 

5 residential, commercial, and industrial buildings present in the restoration of year 2030 will be 

6 constructed between 2000 and 2030 (Brookings Institute 2004), creating opportunities for water 

7 quality improvements that our cities must seize if we are to achieve the goals of restoring the 

8 Chesapeake Bay or any other urban waterbodies.

9 The implementation measures specifically applicable to redevelopment (repeated waters. As 

10 redevelopment projects occur over several decades, pollutant discharges for developed areas can 

11 be gradually reduced as practices are installed to incrementally improve the quality of runoff 

12 from Section 2) are belowexisting, untreated developed land. 

Implementation Measure: Develop and implement redevelopment programs that identify 

opportunities for a range of types and sizes of redevelopment projects to mitigate water resource 

impacts that

• Establish appropriate redevelopment stormwater performance standards consistent with 

the goal of restoring predevelopment hydrology with regard to the temperature, rate, 

volume and duration of flow, or more restrictive if needed for site-specific water quality 

protection

• Include development of an inventory of appropriate mitigation practices (e.g. permeable 

pavement, infiltration practices, green roofs) that will be encouraged or required for 

implementation at redevelopment sites that are smaller than the applicability threshold

• Include site assessment to determine appropriate GI/LID practices

• Review codes and ordinances and modify as appropriate to allow and encourage GI/LID 

practices

• Implement GI/LID demonstration projects

• Incentivize early adopters of GI/LID practices

• Maximize urban forest canopy to reduce runoff

• Conduct soil analyses and amend compacted urban soils to promote 

infiltrationRedevelopment: The process whereby an existing development is adaptively 

reused, rehabilitated, restored, renovated, or expanded, which results in disturbance or 

clearing of a defined footprint at the site.

13 It has been estimated that about 50 percent of the residential, commercial, and industrial 

14 buildings present in the year 2030 will be constructed between 2000 and 2030 (Brookings 

15 Institute 2004), creating opportunities for water quality improvements that our cities must seize if 

16 we are to achieve the goals of restoring the Chesapeake Bay or other urban waters. As 

17 redevelopment projects occur over several decades, pollutant discharges for developed areas can 
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Chapter 3. Controlling Urban Runoff 3-111 

1 be gradually reduced as practices are installed to incrementally improve the quality of runoff 

2 from existing, untreated developed land.

3 Sound redevelopment practices incorporate principles of smart growth and sustainable 

4 development (USEPA 2005, 2006). LID practices installed at redevelopment projects in 

5 catchments that are served by combined sewer systems can help reduce the frequency and 

6 magnitude of combined sewer overflows (CSOs) to rivers and estuaries (Limnotech 2007). 

7 Well-planned redevelopment is necessary for many reasons other than just water quality, 

8 prompting a growing number of redevelopment project designers and communities to develop 

9 holistic approaches for achieving water quality improvements in the redevelopment process in 

10 combination with other social, economic, and environmental factors. Water quality programs are 

11 an important component of a healthy, vibrant, livable, and environmentally sound community 

12 and are a key factor to consider in a redevelopment project. 

13 Encouraging redevelopment, rather than Greenfield development, promotes 

14 • Land use efficiency 

15 • Improves the quality of life in urban areas 

16 • Optimizes use of existing public infrastructure 

17 • Provides a tax base to enable maintenance of existing public infrastructure 

18 LID and green infrastructure stormwater requirements create an excellent opportunity to 

19 facilitate mitigation of the effects of past development at the site or watershed scale, and to 

20 address other societal objectives. 

21 4.2 Challenges and Opportunities in the Redevelopment Sector. 

22 Redevelopment projects require innovative, cost-effective, LID solutions to overcome challenges 

23 such as the following: 

24 Site Constraints. Most infill and redevelopment projects are small in area, highly 

25 impervious, and have existing utilities and infrastructure, all of which constrain the use of 

26 some traditional stormwater practices, particularly those that rely on infiltration through 

27 vegetative practices. 

28 High Trash Loads. Runoff from highly urban watersheds is often severely polluted and 

29 contains a high load of trash, litter, debris and gross solids (COB 2006), which can 

30 interfere with the performance of stormwater practices and creates the need for more 

31 frequent practice maintenance. 

32 Compacted and Polluted Soils. Soils have been graded, eroded, and reworked by past 

33 development, often resulting in compaction such that runoff cannot be effectively 

34 infiltrated. In severe cases, legacy problems from past industrial and municipal activity 

35 have created brownfields that must be capped to prevent infiltration from leaching 

36 pollutants or contaminating soils (USEPA 2008a). For those sites with compacted or 

37 polluted soils, using infiltration practices might be limited. Example case studies are 
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Chapter 3. Controlling Urban Runoff 3-112 

1 provided at EPA’s Brownfields Program 

2 (http://www.epa.gov/brownfields/tools/swcs0408.pdfhttp://www.epa.gov/brownfields/too

3 ls/swcs0408.pdf) 

4 Natural Stream Network is Altered or Buried. Urbanization has severely altered, reduced 

5 or eliminated the natural stream network (NRC 2008). The urban stream system that 

6 remains is often highly degraded and altered in size and shape, and most development 

7 projects discharge to existing storm drain pipes or conveyance channels rather than 

8 streams. 

9 Feasibility and Cost of Compliance. The cost of stormwater practices at redevelopment

10 projects in highly urban settings is often more expensive than in new development 

11 projects in greenfield settings, where more surface land is available for the practices 

12 (Schueler 2007). 

13 Redevelopment Should Focus on Both Source Control (Pollution Prevention) and LID. 

14 Almost without exception, most redevelopment sites in the Chesapeake Bay watershed 

15 and elsewhere in the nation often discharge to receiving waters that are listed as water 

16 quality impaired and require pollutant reductions through TMDLs for a range of 

17 pollutants, including bacteria, trash, nutrients, metals and hydrocarbons. All these varied 

18 sources should be addressed in redevelopment. 

19 Smart Growth Considerations. High-density land development is an essential element of 

20 smart growth, green infrastructure, and sustainable cities. Therefore, it is important that 

21 managers select stormwater practices that will be consistent with those important 

22 redevelopment principles. 

23 Because of those constraints, many urban communities in the Chesapeake Bay watershed (and 

24 elsewhere in the nation) have historically waived, relaxed, or otherwise reduced stormwater 

25 requirements for redevelopment projects. That has contributed to the continuing deterioration of 

26 urban waters. However, in recent years, stormwater managers have taken a more creative 

27 approach to treating stormwater from the redevelopment sector that reflects the following 

28 opportunities: 

29 New Redevelopment Practices. In the past decade, considerable research has been

30 conducted, demonstrations made, and experience gained—all of which demonstrate that a 

31 variety of LID practices can be used that are specifically adapted for highly urban areas 

32 (such as expanded tree boxes, green roofs, and permeable pavements, and flexible rubber 

33 sidewalk sections allowing for less destructive tree root growth). The new practices 

34 emphasize the sustainable use of stormwater as part of green buildings and green 

35 infrastructure. In addition, the new practices promote larger sustainability objectives such 

36 as increased energy efficiency and water conservation, greater building longevity, 

37 community greening, safer and more walkable communities, and more creative 

38 architectural solutions. 

39 Green Building and Sustainability Movement. Designers are seeking LEED certification 

40 for their buildings, and points are awarded for using innovative stormwater practices. 

41 Other certification systems such as the Sustainable Sites Initiative (ASLA 2009) reward 
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Chapter 3. Controlling Urban Runoff 3-113 

1 effective stormwater solutions for the entire site and not just the building itself. Together, 

2 such certification systems provide powerful incentives to create innovative stormwater 

3 solutions for redevelopment projects. 

4 Municipal Leadership on Green Infrastructure. Cities have found that a green approach 

5 to designing their streets, parking lots, and buildings can provide multiple benefits in the 

6 urban setting and have retrofitted their infrastructure designs and building codes to allow 

7 for green streets and streetscapes, urban forestry, and landscaping areas to treat 

8 stormwater (COE 2005; COPH 2008; COPO 2008; SMC 2009). 

9 Alternative Strategy to Abate CSOs. Traditionally, most approaches to reduce the effects 

10 of CSOs have relied on extensive mitigation structures such as deep tunnels and swirl 

11 concentrators to store and treat the overflows. In recent years, however, several cities 

12 have realized that using LID practices on both the existing and redevelopment sectors can 

13 sharply reduce the stormwater inflows into CSOs, and more importantly, greatly reduce 

14 the frequency and magnitude of overflow events (Limnotech 2007). For example, most 

15 residents in Southeast Portland, Oregon, are ready and willing to support an ambitious 

16 program to manage stormwater using a sustainable, or as they often prefer, a natural

17 approach. Residents have a strong orientation toward sustainable living, particularly 

18 around walk/bike-friendly streets and organic and water-wise gardening (Campbell 

19 DeLong Resources, Inc., 2008). The practical benefit is that applying LID practices can 

20 help reduce the large capital costs associated with CSO abatement. For example, the City 

21 of Philadelphia is envisioning embarking on an ambitious project to implement LID 

22 practices to reduce the reliance on underground infrastructure (COPHCity of 

23 Philadelphia, 2009).

24 Other examples of cities that are using LID practices as an integral element of their CSO 

25 abatement projects include Washington, DC; Portland, Oregon; and Milwaukee, Wisconsin. In 

26 New York City, the Riverkeeper report Sustainable Raindrops: Cleaning New York Harbor by 

27 Greening the Urban Landscape evaluates the costs and benefits of using green 

28 infrastructure/LID to help mitigate CSOs (http://www.riverkeeper.org/about29 us/publications/reports). Riverkeeper estimates that for $1,000 invested in the Department of 

30 Environmental Protection’s end-of-pipe projects, CSOs might decrease by 2,400 gallons per 

31 year. By comparison, the same $1,000 investment in:

32 • Green streets could decrease CSOs by 14,800 gallons

33 • Street trees could decrease CSOs by 13,170 gallons 

34 • New green roofs could decrease CSOs by 810 gallons; retrofitted green roofs could 

35 decrease CSOs by 865 gallons; and incentivized green roofs could decrease CSOs by 

36 12,000 gallons 

37 • Rain barrels could decrease CSOs by 9,000 gallons 

38 That indicates the value of incorporating LID practices in redevelopment. 
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Chapter 3. Controlling Urban Runoff 3-114 

1 4.1 Establish 3 Stormwater Performance StandardsGoals for the 

2 Redevelopment Sector Consistent with the Goal

3 A number of Restoring Predevelopment Hydrology

4 For all redevelopment sites, establish the means of determining compliance with thedifferent 

5 numeric performance standardgoals have been established for runoff volume reduction or 

6 pollutant reduction. stormwater management in the redevelopment sector, as described below:

7 The federal government is leading by example by requiring runoff volume reduction that would 

either be equivalent to that of predevelopment hydrology, or as a default depth, from the 95th 8 

9 percentile rainfall event. That requirement applies for redevelopment projects at federal facilities 

10 and lands nationwide, and is described in U.S. DoD (2009) and USEPA (2009b). It is derived 

11 from section 438 of the 2008 Energy Independence and Security Act. In the Chesapeake Bay 

12 watershed, that LID requirement would apply to about 1.5 to 1.9 inches of rainfall, depending on 

13 where the project is in the watershed. 

14 • Several cities such as the District of Columbia, Philadelphia, Los Angeles and states such 

15 as Pennsylvania and New Jersey promote sustainable stormwater management and have 

16 established their own requirements for runoff reduction for redevelopment sites that meet 

17 or exceed those required by the state.

18 4.24 Stormwater Management Practices for Redevelopment 

19 A unique set of practices are commonly used to reduce runoff and pollutant loads from the 

20 redevelopment sector, as shown in Table 3-42. The practices can be applied to address untreated 

21 impervious or pervious areas in the redevelopment sector.

22 Table 34-42: Example practices for addressingPractices for Addressing the redevelopment 

23 sectorRedevelopment Sector

Treat impervious cover Manage pervious areas 

Green Roofs 

Rainwater Harvesting, including Blue Roofs 

Foundation Planters 

Permeable Pavers 

Expanded, Compaction-protected Tree Pits 

Flexible Rubber Sidewalk Sections for Tree Pits

Urban Bioretention 

Bioretention 

Conserve and Restore Natural area Remnants 

Soil Amendment and Restoration 

Reforestation 

Conservation Landscaping

Turf Management

Impervious Cover Reduction 

Create Functional Bioretention from Elevated 

Parking Lot Islands and Traffic Medians 

Note: Where surface area is available, typical on-site LID stormwater practices from the new development sector 

can be used to comply. In addition, when feasible on-site practices are not capable of achieving full attainment of 

predevelopment hydrology, restoration practices from the existing development areas may help in mitigation. For 

more detailed information on each practice, please consult the practice profile sheets in Section 6 of this Guide 
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Chapter 3. Controlling Urban Runoff 3-115 

1 Key considerations in applying these practices are as follows: 

2 • Use a Roof to Street Design Approach. Break the site into smaller drainage areas with a 

3 unique LID solution for each area (e.g., roofs, pedestrian areas, streets, open space and 

4 parking lots). In that manner, stormwater management is directly integrated into the 

5 design of buildings, parking lots, hardscapes, open spaces, landscaping, and streetscapes. 

6 That avoids the need for underground structures or consumption of costly surface real 

7 estate for stormwater practices. The basic approach includes 

8 – Managing rooftop runoff through green roofs, water harvesting, disconnection, or 

9 storage and release from foundation planters 

10 – Minimizing surface parking or designingdesigned surface parking to reduce, store, 

11 and treat stormwater using permeable pavements, bioretention, or biofiltrationsand 

12 filters (see SMC 2009) 

13 – Designing urban hardscapes such as plazas, courtyards, and pedestrian areas to store, 

14 filter, and treat runoff using permeable pavers (with storage in the void space of 

15 underlying gravel), stormwater planters, and amenity bioretention areas 

16 – Ensuring that all pervious and landscaping areas in the redevelopment project are 

17 designed for effective stormwater treatment using practices such as soil restoration, 

18 reforestation, and bioretention 

19 – Designing the streetscape to maximize the capture and reuse of stormwater runoff by 

20 using expanded tree pits, street bioretention, curb cut extensions, and other green 

21 street methods (see COPO 2008; COPH 2008; and SMC 2009) 

22 An example of such a design approach is the redevelopment of an office building at 1050 

23 K Street, NW, Washington, DC, in the downtown business district, shown in Figure 3-18. 

24 Figures 3-19 and 3-20 provide additional redevelopment examples. 

25 • Reduce Real Impervious Cover. Ensure that pervious cover performs hydrologically as if 

26 it were an undisturbed pervious area. Deep tilling and amending soils with compost and 

27 other materials can increase porosity and water holding capacity. In many cases, runoff 

28 from rooftops can be effectively disconnected and drained over such improved pervious 

29 areas. 

30 • Identify and Treat Hotspot-Generating Areas. Require that contributing drainage areas 

31 from stormwater hotspots be isolated from the remainder of the site (usually by grading 

32 and drainage) so that the runoff can be fully treated to prevent toxic discharges to surface 

33 water or groundwater. 

34 • Adapt LID to Urban Design. Adapt principles such as Better Site Design (CWP 1998) to 

35 urban environments. Examples include innovative urban parking management solutions 

36 (COE 2005), municipal green street specifications (SMC 2009), context-sensitive road 

37 design standards providing stormwater treatment in the right-of-way (MC 2008), and 

38 modifications to traditional streetscape standards to use street trees as a stormwater 

39 filtering device (COPO 2008; Cappiella et al. 2006; Stormwater Magazine March/April 

40 2010). 
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Chapter 3. Controlling Urban Runoff 3-116 

The potential for green infrastructure to mimic natural systems even in the densest of cities is 

demonstrated at 1050 K Street—a LEED Gold-certified office building in the heart of Washington, DC, on

the site of a former parking lot. The site had been 97 percent impervious. The project design reduced 

impervious area to 67 percent. Runoff from the property occurs only in a major storm event because of 

the green infrastructure practices employed in the building design: 

• Two tiers of green roofs retain rainwater falling on the rooftop 

• Three bioretention cells in the building plaza retain and treat runoff from adjacent impervious areas

• A 5,000-gallon cistern beneath the building complements these features by storing any stormwater 

that cannot be retained. 

• All irrigation water is from the cistern, reducing building water consumption and maintaining cistern

storage capacity. 

This suite of green infrastructure practices provides stormwater benefits, an urban oasis for the tenants 

and passers-by, and a competitive advantage for the building owners (Lanier 2007). 

 

1 Figure 3-18. Redevelopment stormwater retrofits at 1050 K Street, Washington, DC. 

Photos, courtesy Lu Gay Lanier, The Timmons Group
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Chapter 3. Controlling Urban Runoff 3-117 

1 

In 2009 Manassas Park, Virginia, expanded the elementary school, using an existing impervious 

parking lot as the site. The new school incorporates many natural educational features, a historic site, 

and functional stormwater features. Native plants and no-mow meadow grasses are used to enhance 

the educational experience. The post-development runoff is slightly lower than predevelopment 

conditions. See a video highlighting the features at http://vimeo.com/chesapeakebay. 

A 75,000-gallon rainwater cistern, built to potable water standards, collects rainwater from the entire 

rooftop area and is used for toilet flushing and irrigation. It is estimated to conserve 1.3 million gallons of 

water per year. An outdoor classroom with semicircular, stepped seating doubles as a stormwater 

bioretention cell. 
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Chapter 3. Controlling Urban Runoff 3-118 

1 

2 Figure 3-19. Manassas Park Elementary School. 

In 2009 Manassas Park, Virginia, expanded the elementary school, using an existing impervious 

parking lot as the site. The new school incorporates many natural educational features, a historic site, 

and functional stormwater features. Native plants and no-mow meadow grasses are used to enhance 

the educational experience. The post-development runoff is slightly lower than predevelopment 

conditions. See a video highlighting the features at http://vimeo.com/chesapeakebay. 

A 75,000-gallon rainwater cistern, built to potable water standards, collects rainwater from the entire 

rooftop area and is used for toilet flushing and irrigation. It is estimated to conserve 1.3 million gallons of 

water per year. An outdoor classroom with semicircular, stepped seating doubles as a stormwater 

bioretention cell. 
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Chapter 3. Controlling Urban Runoff 3-119 

1 

The Yorktown project serves as a model for residential and business communities demonstrating how 

green roofs and other stormwater management designs can be implemented to improve water quality, 

decrease erosive stormwater, and conserve flora and wildlife resources in the Chesapeake Bay 

watershed. 

In designing the green roof, structural concerns relative to the 30-year-old building were a major factor 

in the decision to use a lightweight building system incorporating waterproofing, root barrier, water 

retention, and drainage system in one layer. The 15 pound/square foot capacity had to include all 

weight associated with the waterproofing, growing media, water retention system, and mature 

vegetation (fully saturated and fully hydrated). The project, including membranes cost $12 per square 

foot (sf) (for a 4,700-sf green roof system). 

It is estimated that the green roof provides a 20 percent reduction in cooling cost and should enjoy a life 

expectancy of more than 40 years. Initial reports confirm that 80 percent of the annual rainfall is 

retained on the roof, via a hydrogel technology along with the design of the porous growing media. 

Other storm water management features consist of rain gardens, a bioswale, and a federally protected 

biohabitat. 
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Chapter 3. Controlling Urban Runoff 3-120 

1 

2 Figure 3-20. Yorktown Square Condominiums, Falls Church, Virginia. 

3 4.2.15 Practice Integration and Assessment Tools 

4 Effective application of the roof-to-street design approach in the redevelopment sector requires 

5 creative integration of stormwater practices in buildings, courtyards, streetscapes, and parking 

6 lots. Multiple practices are used to treat and reduce runoff from small and different urban 

7 surfaces, using a treatment train approach to help ensure the best performance. Redevelopment 

8 programs should identify opportunities for a range of types and sizes of redevelopment projects. 

9 Practices should be identified that can be encouraged or required for implementation at sites even 

10 below applicability area thresholds. 

11 Several tools have been developed to track progress in meeting the performance standards for the 

12 redevelopment sector, and optimize the best and to identify most cost-effective combinations of 

13 practices at the site. Such tools include the following: 

14 • A series of spreadsheets that allow the user to break the site into smaller drainage areas 

15 and size and optimize the most appropriate practices for them. For example Emeryville, 

16 California (COE 2005), developed a spreadsheet-based calculator to determine the proper 

17 size of stormwater treatment devices for new development projects 

18 (see http://ca-emeryville.civicplus.com/DocumentView.aspx?DID=109). Virginia 

The Yorktown project serves as a model for residential and business communities demonstrating how 

green roofs and other stormwater management designs can be implemented to improve water quality, 

decrease erosive stormwater, and conserve flora and wildlife resources in the Chesapeake Bay 

watershed. 

In designing the green roof, structural concerns relative to the 30-year-old building were a major factor 

in the decision to use a lightweight building system incorporating waterproofing, root barrier, water 

retention, and drainage system in one layer. The 15 pound/square foot capacity had to include all 

weight associated with the waterproofing, growing media, water retention system, and mature 

vegetation (fully saturated and fully hydrated). The project, including membranes cost $12 per square 

foot (sf) (for a 4,700-sf green roof system). 

It is estimated that the green roof provides a 20 percent reduction in cooling cost and should enjoy a life 

expectancy of more than 40 years. Initial reports confirm that 80 percent of the annual rainfall is 

retained on the roof, via a hydrogel technology along with the design of the porous growing media. 

Other storm water management features consist of rain gardens, a bioswale, and a federally protected 

biohabitat. 
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Chapter 3. Controlling Urban Runoff 3-121 

1 Department of Conservation and Recreation (VA DCR 2009) developed a spreadsheet2 based tool to estimate stormwater volume reduction and pollutant removal (see 

3 www.dcr.virginia.gov/lr2f.shtml). 

4 • Philadelphia uses a series of checklists and worksheets to achieve the same purposes 

5 (COPH 2008) (see 

6 www.phillyriverinfo.org/PWDDevelopmentReview/RequirementsLibrary.aspx#www.phi

7 llywatersheds.org/what_were_doing/documents_and_data/cso_long_term_control_plan).

8 Urban communities in the Chesapeake Bay watershed and elsewhere should adapt and modify 

9 such integration tools to meet their unique redevelopment conditions. 

10 Designers might also maximize stormwater LEED points to obtain green building certifications 

11 or use the performance benchmarks for sustainable stormwater initiatives (ASLA 2009). See the 

12 example in Figure 3-21. 

13 

The Eastern Village Condominiums structure is a redevelopment of a former office building that has 

been transformed into 56 condominium units in a thriving urban community. It is the first LEEDcertified cohousing structure. Before construction, the site was more than 90 percent impervious 

while the new design decreased the imperviousness of the site to 54 percent. Practices installed at 

the site include a green roof, a vegetated courtyard, and rain barrels. 

Roof area: 12,330 sf 

Planted area: 8,000 sf 

Cost: $36/sf (2006) 
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Chapter 3. Controlling Urban Runoff 3-122 

1 

2 Figure 3-21. Eastern Village Cohousing Condominiums HOA, Silver Spring, Maryland 

3 4.3 Site Evaluations

4 Site evaluations should be conducted to determine the 

5 appropriateness of infiltration practices. Soils should be 

6 evaluated to 4.6 Programmatic Practices for the Redevelopment 

7 Sector

8 The following recommendations help address redevelopment program implementation:

9 Define Redevelopment. Clearly define redevelopment and the minimum land area 

10 triggering stormwater requirements.

11 Establish Redevelopment Stormwater Performance Standards. Establish a defined 

12 performance standard for runoff volume reduction or pollutant reduction for all 

13 redevelopment sites. If it is technically infeasible to achieve predevelopment hydrology 

14 on-site, provide an offset or a mitigation fee if full compliance is not possible. Use funds 

15 from the offsets to finance stormwater retrofit and restoration projects elsewhere in the 

16 subwatershed.

The Eastern Village Condominiums structure is a redevelopment of a former office building that has 

been transformed into 56 condominium units in a thriving urban community. It is the first LEEDcertified cohousing structure. Before construction, the site was more than 90 percent impervious 

while the new design decreased the imperviousness of the site to 54 percent. Practices installed at 

the site include a green roof, a vegetated courtyard, and rain barrels. 

Roof area: 12,330 sf 

Planted area: 8,000 sf 

Cost: $36/sf (2006) 
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Chapter 3. Controlling Urban Runoff 3-123 

1 Conduct Site Investigations. Evaluate soil conditions and determine whether the site is subject to 

2 brownfield remediation. Stormwater designers can use the assessments to determine if 

3 stormwater runoff can be infiltrated, soils need to be capped, environmental and utility 

4 constraints exist, or natural area remnants can be protected or restored. The investigations are 

5 also useful to map the best locations for LID practices and how they can be connected as an 

6 effective system. 

7 4.4 Codes and Ordinance Review

8 Review Codes and Ordinances. Change or supplement codes and ordinances as necessary to 

9 allow the use of certain redevelopment practices (e.g., rainwater harvesting/plumbing codes, 

10 green roofs/building codes; green streets/road codes). See EPA’s Water Quality Scorecard

11 (http://cfpub.epa.gov/npdes/greeninfrastructure/munichandbook.cfm) (USEPA 2009d),), Better 

12 Site Design: A Handbook for Changing Development Rules in Your Community (CWP 1998) and 

13 NRDC’s Out of the Gutter: Reducing Polluted Runoff in the District of Columbia

14 (www.nrdc.org/water/pollution/gutter/gutter.pdf). 

15 4.5 Implement Demonstration Projects

16 : Implement demonstration projects to promote and demonstrate green infrastructure techniques. 

17 That approach is proven to promote progress in implementing innovative practices. 

18 4.6 Incentives for Incentivize Early Adopters

19 . Offer the private sector incentives to install more expensive or (locally) experimental practices. 

20 For example, New York City (Jones 2009) and), the District of Columbia (Anacostia Watershed 

21 Society and DC Department of the Environment 2010) and Baltimore (Green Building Template: 

22 A Guide to Sustainable Design Renovating for Baltimore Rowhouses. Prepared by TerraLogos: 

23 ECO Architecture for the Maryland Department of Natural Resources. December 2001) offer 

24 direct subsidies to partially defray the cost of installing blue roofs and green roofs, and several 

25 west coast communities offer stormwater utility fee discounts for redevelopment projects that use 

26 green streets or green parking lots. 

27 EPA provides examples of program types and municipal case studies in the Managing Wet 

28 Weather with Green Infrastructure Municipal Handbook Incentive Mechanisms (USEPA 2009a).

29 The following are the primary types of green infrastructure incentives:

30 Stormwater Fee Discount: Base the stormwater fee on impervious surface area. If property 

31 owners reduce need for service by reducing impervious area and the volume of runoff discharged 

32 from the property, the municipality reduces the fee.

33 Development Incentives: Offered to developers during the process of applying for development 

34 permits. Examples include: zoning upgrades, expedited permitting, reduced stormwater 

35 requirements and increases in floor area ratios.

36 Grants: Provide direct funding to property owners and/or community groups for implementing a 

37 range of green infrastructure projects and practices.
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Chapter 3. Controlling Urban Runoff 3-124 

1 Rebates & Installation Financing: Provide funding, tax credits or reimbursements to property 

2 owners who install specific practices. Often focused on practices needed in certain areas or 

3 neighborhoods

4 Awards & Recognition Programs: Provide marketing opportunities and public outreach for 

5 exemplary projects.

6 4.7 Maximize Urban Forest Canopy

7 . Maximize vegetation and forest canopy across the site to gain incremental stormwater treatment 

8 using expanded tree pits, green roofs, foundation planters, and urban bioretention. Information 

9 on urban forestry practices is in section 2, and in the fact sheet on reforestation/urban forestry in 

10 section 6.

11 4.8 Amend CompactedAmend compacted urban soils. Urban Soils

12 Urban soils are often compacted resulting in poor infiltration rates. Amending the soil with 

13 compost or another soil mixture can significantly increase the infiltration rate for the soils.

14 Information on soil amendment practices are in section 5 on turf management, and in the fact 

15 sheet on soil amendment in section 6.

16 Exercise Caution with Urban Soil Contamination. Exercise caution in infiltration of 

17 stormwater runoff in redevelopment projects with contaminated soils. Infiltration should 

18 generally be avoided when site history indicates that the site was a stormwater hotspot or 

19 a brownfield. In such situations, EPA recommends using lined stormwater filtering 

20 practices such as sand filters and bioretention to prevent groundwater contamination (see 

21 Schueler 2007 or USEPA 2008).

22 4.9 7 References 

23 ASLA (American Society of Landscape Architects). 2009. Guidelines and performance 

24 benchmarks. Sustainable Sites Initiative Project. American Society of Landscape 

25 Architects, Washington, DC. 

26 Brookings Institute. 2004. Toward a new metropolis: the opportunity to rebuild America. Arthur 

27 Nelson. Virginia Polytechnic Institute and State University. Discussion Paper. Brookings 

28 Institution Metropolitan Policy Project, Washington, DC. 

29 Campbell DeLong Resources, Inc. 2008. Citizen Response to Sustainable Stormwater 

30 Management in Inner Southeast Portland. Focus Group Research Conducted for City of 

31 Portland Environmental Services, Portland, OR.. 

32 Cappiella, K., T. Schueler, and T. Wright. 2005. Urban Watershed Forestry Manual. Part I: 

33 Methods for Increasing Forest Cover in a Watershed. U.S. Department of Agriculture 

34 Forest Service, Newtown Square, PA 
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